Malawian cichlids. Intertidal zone (estuaries) Marine life in polar ecosystems

Snow flakes, so softly falling on the mountain peaks, are the most destructive force. They form into snow caps many meters thick. The lower layers of the caps under the pressure of the upper ones are converted into ice. It binds protrusions, penetrates into cracks and clefts. And the snow keeps falling, and the ice, under the influence of its own gravity, begins to slide down the slope, dragging away stone blocks and slabs. Usually the movement is so slow that only the widening breaks in the snow cover give it away. But sometimes a huge layer suddenly breaks off from all supports, and thousands of tons of ice, snow and stones roll into the valley.

All the big rivers, the Amazon and the Zambezi, the Hudson and the Thames, as well as thousands of lesser ones, reach their estuary completely muddy with rainfall. Even the most transparent river waters are full of microscopic particles - mineral and decomposed organic substances. Mixing with salts dissolved in sea water, they stick together and sink to the bottom, forming huge mudflats.

Estuary silt has a very special texture, stickiness and smell. If you step into it, it will stick to your leg so much that it can tear off your boot. It is so fine-grained that the air does not seep through it, and the gases released by the decaying organic residues inside it remain there until they escape from under your soles, dousing you with the smell of a rotten egg.

Twice a day, the nature of the waters washing these mudflats changes dramatically. At low tide, especially when the rivers are swollen with rain, fresh water predominates, while at high tide, the water in the estuary can be equal in salinity to sea water. And twice a day, a significant part of the silt can come out of the water into the air. It is quite obvious that organisms living in such a place must be resistant to numerous changes in physical and chemical conditions. But the benefits associated with this are very great, for the estuary receives daily food from both the river and the sea, and potentially the water in it is richer in nutrients than any other - both salty and fresh. And therefore, those few organisms that withstand such stringent requirements thrive there in incredible numbers.

At the upper end of the estuary, where the water is only slightly brackish, live thin as hairs tubule worms. Their front end is immersed in the silt into which they eat, and the back end waves in the water in order to better be washed with oxygen. Up to half a million of them can live on one square meter of silt, and they cover it like thin reddish-red wool. Closer to the sea, where the water is slightly saltier, hordes of centimeter-long crustaceans build burrows for themselves and sit in them, capturing the passing nutrient particles with hooked antennae. Tiny, wheat-sized rissoid snails extract food from the upper creamy layer of silt, and with such success that more than forty thousand of them were extracted from one square meter.

Closer to the ebb tide, especially where sand is mixed with silt, sandworms live. These worms also feed on silt, but enrich it before they consume it. Each sandworm, about forty centimeters long and as thick as a pencil, digs a hole in the form of a steep arc with two exits to the surface and strengthens the walls, lining them with mucus. It fills the upper part at one exit from the arc with loose sand, and then, clinging to the walls with bristles on its sides, it begins to move back and forth along the bottom of the mink, like a piston in a pump, drawing water through its sand filter. The organic particles it carries get stuck in the sand. Having ceased pumping water, the worm begins to eat sand, digesting everything edible in it, and spewing the rest into the other horn of the arc. Approximately every three-quarters of an hour, he pushes the spewed sand out of the mink, so that neat pyramids form at the exit. In the same place, at the very surface of the water, heartworms are buried. These mollusks do not compete with sandworms for silt, but suck up food directly from the water through two short, fleshy siphons.

At low tide, all these creatures stop feeding and take steps to keep themselves from drying out. The silt around the rissoids has not yet completely compacted, and the water, receding, carries away most of it, and tiny snails lie on top of each other in layers a few centimeters thick. Each seals the entrance to the shell with a small disc that completes its leg. The cockles tightly squeeze the valves of their shells, and the sandworms simply remain in the mink, which is so deep that the water does not escape from it.

But desiccation is not the only danger threatening these creatures during low tide hours. All of them are vulnerable to air attack, and hungry birds now flock to the estuary. The food they choose is largely determined by the size and shape of the beak. Crested duck and red-headed pochard rummage through the silt and grab tubifexes. Plovers and plovers with short sharp beaks gorge themselves on rissoids, extracting the body of the mollusk coiled in a spiral with a lightning strike. Herbalists and sandpipers, whose beaks are twice as long, probe the top layer of silt in search of crustaceans and small worms. Oystercatchers with strong scarlet beaks specialize in heartworms. Some open shell shells, others choose smaller and thinner shells and break them. Curlews and Godwitches, who have the longest beaks, reach the sandworms and extract them from their burrows.

And the river still carries new sediments, and the shoals are gradually growing. A green film of algae begins to form on them, compacting particles of silt. As soon as this happens, other plants can already take root in it. Now the silty shoals begin to rapidly rise higher and higher, as the particles of silt brought by the splashing waves are no longer carried back by the ebb, but are retained by the roots and stems of plants. Little by little, they rise so high that they hide under water only at the highest tides. Their shores are strengthened, and the inhabitants of the estuary have to cede their territory to the inhabitants of the land.

On the European coasts, an active role in this process belongs to the saltwort, a small plant that, with scale leaves and swollen translucent stems, resembles desert succulents. Actually, the similarity is not simple. Flowering plants have evolved on land, and all their chemical processes are connected with fresh water. Sea water is dangerous for them, because due to the salts dissolved in it, its density is higher than that of their juice, and their roots begin to exude moisture, and not absorb it. Therefore, plants in a salty environment need to accumulate moisture in themselves just as much as cacti in the desert.

In tropical estuaries, silt is retained by mangrove forests, consisting of shrubs and trees - both low and twenty-five meters high. They come from different families, but the conditions of life in brackish swamps led to the development of similar features in all of them.

Trees first of all have to solve the problem of how to survive in viscous unsteady silt. Deep roots are useless here, because warm silt already a few centimeters below the surface is deprived of oxygen and sour to causticity. This is why mangrove trees have a flat root system that rests on the surface of the mud like a raft. Taller trees receive additional stability due to the curved roots extending from the middle part of the trunk, which serve as props for it. At the same time, the roots must provide the tree not only with stability, but also with nutrition; and the horizontal position of the mangrove root system contributes a lot to this, since the nutrients necessary for the tree are not buried in acidic mud, but lie on its surface, where they were left by the tide.

The roots also help the tree get oxygen and get rid of carbon dioxide, a product of its life processes. Again, there is no oxygen in the mud. Mangroves get it directly from the air through small areas of spongy tissue in the bark on prop roots. In the same mangroves that have not acquired such roots, this tissue is located on the nodular vertical outgrowths of horizontal roots. The mangroves that grow closer to the sea have developed conical respiratory roots that, unlike ordinary roots, grow vertically upwards, outpacing the silt that settles there faster, and surrounding the tree with countless rows of sharp pegs that most of all resemble some kind of fantastic defensive system in the medieval spirit.

Salt causes the same problems for mangroves as it does for saltwort. They also have to keep moisture in their tissues, and they prevent it from evaporating in the same ways as desert plants - dense waxy skin on leaves, the location of stomata at the bottom of tiny dimples. But they still need to prevent the accumulation of salt in their tissues, which would seriously disrupt their life processes. Some mangroves manage not to draw it in with water thanks to a special membrane that covers the roots, as, in particular, in saltwort. Others, deprived of such protection, suck up the dissolved salt by their roots, but get rid of it before its concentration becomes dangerous. They either have special organs in the leaves that exude a rather strong saline solution, or from the juice it enters the already drying leaves, which then fall off along with all the excess salt.

As silt accumulates on the seaward side of the mangrove swamp, mangrove plants immediately master it with the help of special seeds that germinate on branches and release a stem that reaches almost half a meter in some species. Some of these seeds fall straight down on the tangled roots and take root there. The underside releases roots, and the stem unfolds the leaves. Others fall at the height of the tide, which carries them away. In brackish marsh water they float upright, but if the tide drags them out to sea, in denser sea water they rise higher into the air and capsize. In this horizontal position, the green skin cells begin photosynthesis and nourish the young plant. The tender bud at the end, which is to be given leaves, remains moist, not scorched by the sun, and cools all the time. In this position, the mangrove baby remains alive for up to a year, having traveled hundreds of kilometers during this period. If the current eventually carries it into another estuary with less saline water, it will again assume a vertical position, with its roots down. When, at low tide, the tips of the roots touch the soft silt, they begin to grow into it and branch at high speed, and after a while a new mangrove tree rises to the sky.

The mangrove swamp can be crossed by several free channels, but in general it is so densely overgrown that even the smallest and narrowest shuttle gets stuck there. If you intend to explore such a swamp, you can do this only on foot during low tide hours. This is not the best place to walk. Thick, curved support roots constantly sag under your weight and the foot slides off. Many are lined with sharp shells that scratch your shin if you slip, or split your palms if you try to grab onto them so as not to fall headfirst. Everywhere smells of rot. Water drips and trickles down from the roots. Clicking sounds are heard in the stuffy air - these are crabs and mollusks hiding in their shelters, tapping their claws and slamming their shells. Mosquitoes squeak all around and sting you mercilessly. The branches overhead are so intertwined that not the slightest breeze brings coolness, and the air is so saturated with dampness that sweat pours from you in hail. And yet, the mangrove swamp has a peculiar undeniable beauty. Water seeping through the roots casts silvery reflections on the undersides of the leaves. Crossing arcs of support roots, pegs sticking out of the silt and nodes of respiratory roots form endless patterns. And life is everywhere.

A whole army of various animals is busy collecting food left by the ebb. Small littorin-like sea snails slowly crawl along the silt, eating scraps of algae. Ghost crabs, five centimeters across, scurry about it in search of organic debris, looking for danger with eyes that are not placed on the tips of long stalks, but surround them, providing the crab with a 360 ° field of view. Alluring crabs carefully emerge from their holes and are accepted to process the surface layer: they grab a dense lump with claws and bring it to a pair of jaws bordered with bristles, moving back and forth in front of the mouth opening. The lump of grains of sand is held together by the spoon-shaped bristles of one jaw, while the others sweep all the nutritious particles from it into the mouth behind. Inedible grains of sand accumulate in the lower part of the mouth apparatus, where they are compacted into a ball, which the crab picks up with its claws and throws it away, moving to a new place to repeat the whole operation from the beginning.

The females of the fiddler crab use both claws, while the males are forced to make do with one claw, the same as that of the females, while the second is noticeably larger and brightly colored in pink, blue, purple, or shines with white. Its purpose is to serve as a signal flag. The male waves it to the female while doing pirouettes. In different species, choreography and semaphore are combined in their own way. Some rise on tiptoe and draw circles with their claws, others frantically swing them from side to side, others do not move their claws, but bounce. But the meaning is always the same: the male is ready to mate. The female, having learned the signal of her species, sooner or later will run up to the male, follow him into his mink, where they will mate.

Crabs originated in the sea, where most of their species still live today, breathing with the help of gill chambers inside the shell, through which oxygenated water is passed. Fiddler crabs, however, also need to breathe in the air. They solve this problem simply by keeping water in the gill chambers. Naturally, oxygen in such a small amount of water is soon depleted, but the crab immediately renews its supply, driving water through the mouth apparatus and whipping it into foam. The newly oxygenated water returns to the gill chamber.

Fish also come out of the water and crawl through the silt of the mangroves. These are mudskippers. The largest of them are about twenty centimeters long. Like crabs, they store water in the gill chambers, but they cannot enrich it with oxygen and regularly return to the ducts to replace the previous supply with fresh water. But these fish have an absorbent surface that hard-shelled crabs lack: skin. And a significant part of the oxygen they need is obtained through it, much like frogs. However, for this the skin must be moist, and jumpers from time to time quickly roll over the silt to wet the sides.

When they need to rush forward quickly to grab a crab or avoid danger, they turn their tail to the side, snap it and fly through the mud like a bullet. However, they usually move much more slowly, relying on pectoral fins, which have bony supports inside the body, are controlled by strong muscles and are equipped with a joint, so that it looks like the jumper is crawling, leaning on his elbows. In some species, another pair of fins closer to the abdomen has merged into a sucker, with which such mudskippers can be held on roots and trunks.

These fish live in mantras in many areas of the world. There are usually three main species in each swamp. The smallest stays in the water the longest and gets out of it only at low tide. Flocks of them crawl in liquid silt at the water's edge, filtering it in search of small worms and crustaceans. The area flooded in the first hours of the tide belongs to noticeably larger jumpers. These are vegetarians, content with algae and other single-celled plants. Each fish has its own area in which it digs a hole for itself, jealously guarding the silt around. Sometimes it encloses its territory with low ramparts of silt with a total length of several meters in order to prevent neighbors from entering it, and also to some extent prevent complete drainage of the silt. Where the populations are numerous, these areas merge and the entire shoal is divided into polyhedrons. Inside each walks the owner, like a bull through a fenced meadow. The third type of mudskipper occupies the highest part of the swamp. These are predators that prey on small crabs. They have holes, but the rights to the surrounding territory are not claimed, and several jumpers can search for prey in the same area without disputing it from each other.

Mudskippers not only feed out of the water, but also conduct mating courtships there. Like most fish, they wave and vibrate their fins. Since both pairs of fins are used for locomotion, two long dorsal fins are used in the courtship ritual. Usually they are pressed to the back, but, starting courtship, the male rears them, and they amaze the eye with the brightness of their color. But this alone is not enough to attract a friend: on a flat swamp, a small fish is visible only to its neighbors. Therefore, the male jumper, demonstrating his beauty to the largest possible number of spectators, beats with his tail and soars up, unfolding the banners.

The species that lives at the water's edge, as far as we know, does not care about its offspring in any way. The low tide carries away the fry as soon as they hatch, and the tiny jumpers join other fry and larvae drifting near the sea surface. The vast majority of them will become someone's prey or will be carried away to the open sea far from the mangrove swamps, and they will die.

The second species, however, provides some protection to its young. The male digs a hole in the middle of a fenced area and surrounds the entrance to it with an annular shaft. The silt here is so close to the level of non-flowing water that a pond forms inside the shaft. The male is located on the shaft, where the female comes to him. Mating takes place in a secluded burrow at the bottom of a pond. Caviar is laid there, and fry remain there even at the height of the tide, until they grow up so much that they are already able to escape from enemies.

The third type of mudskippers does not build ponds - perhaps at a higher level they would be poorly filled. But their minks are very deep and go into the mud for more than a meter. And there is always water at the bottom, so at first the juveniles are protected.

Mudskippers, like alluring crabs or oysters, are essentially marine animals that have adapted to spend part of their life in water, and part in the air. And some animals moved to the swamp from other places and adapted to the same.

In Southeast Asia, a small snake crawls into mangroves to hunt mudskippers, which even penetrates into their holes. She perfectly adapted to life in the water: her nostrils close, and a special valve in her throat closes when she opens her mouth under water to grab prey. Another snake, a close relative of the first, does not hunt fish but crabs, and has developed a poison that is especially effective on crustaceans. The third snake on the nose, oddly enough, has two movable tentacles that help her navigate the muddy water. These swamps are also inhabited by an amazing frog, the only one in the world whose skin can withstand contact with salt water. She feeds on insects and crustaceans.

The most enterprising, curious and omnivorous visitors to the mangroves are monkeys, crabeater macaques. Macaques on their hind legs fearlessly enter the water up to their waists. Crabs are his favorite treat. Usually, the agile crab first manages to slip away from the monkey into a hole, but the monkey settles down near the entrance and waits patiently. In the end, the crab cautiously looks out, checking if everything is calm around, and then the monkey grabs it. But he should be careful, because the crab has claws, and often the hunt ends with the furious cries of the monkey, which waves its injured paw in the air.

Twice a day the huge silt arena juts out into the air and is flooded twice. Water returns quickly and silently. The balls of roots disappear under the running ripples, and the mangrove forest is transformed. For some of the inhabitants of the silt - worms, crustaceans and mollusks - this brings a pleasant respite. They are no longer in danger of being attacked from the air or in danger of drying out. But for others, things are getting worse. Some crabs are so adapted to breathe air that they die when immersed in water for a long time. And everyone builds a vault over his mink that holds an air bubble - oxygen in it is enough for the crab until the next retreat of the water. Small mudskippers climb up the roots as if fleeing a flood. Perhaps these are young individuals who have not yet acquired their own territories, and therefore they do not have a mink to hide in it when large hungry fish swim in with the tide in the mantras. Yes, juveniles, perhaps it is safer to wait out the tide in the air.

Algae-eating sea snails also crawl up the roots next to jumpers. If they remained on the muddy bottom, where there are no stones with secluded cracks, they could also become victims of fish. However, they cannot move at the speed of jumpers and have difficulty keeping up with rising water, so they leave their silty pastures long before the tide reaches them, demonstrating a remarkably accurate sense of time. Their internal clock gives them even more complex signals. On certain days of the month, the tides are exceptionally high, and the snails would not have had time to climb out of reach. During such periods, they not only do not descend into the mud between high tides, but, on the contrary, crawl higher along the mangrove roots so as not to be trapped.

Insects that fed on the silt, also fleeing from the water, are in abundance on the mangrove roots and under the leaves. However, even there they are in danger. Along with other fish, counting on something to profit from in the mangroves, archers swim there, keeping close to the surface of the water. They are more than twenty centimeters long, their eyes are large, and the lower half of their mouth is protruding. Their eyesight is so sharp that, despite ripples and refraction, they distinguish an insect sitting above the water. Having outlined the prey, the archer presses its tongue against a long groove in the palate, sharply closes the gill covers and throws up a jet, as if from a water pistol. The fish may have to repeat this operation once or twice, but it does not give up, so in the vast majority of cases the jet eventually knocks the insect into the water, where it is immediately swallowed. Insects nestled higher attract other predators. Ghost crabs climb trees, turn over leaves and grab the flies sitting there with their claws.

Refugees hiding on the roots remain under siege for several hours. But then the ripples on the water disappear, and for several minutes it seems motionless. The tide begins. Ripples appear again, but now they go around the roots on the opposite side: the swamp is again gradually drained. As the water leaves, it leaves a fresh supply of edible bits for crabs and mudskippers, as well as a new layer of sticky silt that extends the mangroves just a tiny bit into the sea.

If land advances in the estuary, then in other places the offensive is carried out against it. Where the seashore is not protected by sediments, and especially where it forms cliffs, the waves beat at its base. During storms, the waves, raging, throw sand and heavy stones into the cliff. This constant bombardment unmistakably reveals all the weak points of the cliff - the cracks hiding in it, the slightly softer layers of the rock - and over time they turn into deep clefts and caves. The land is receding, and only lonely bizarre rocks remind where its former border passed not so long ago. Larger stones hit the very bottom of the steep bank, causing it the greatest damage, undermining it. And here comes the big chunk. For some time, a pile of stones will protect the base of the cliff. But little by little, the sea takes possession of the debris - it rolls the larger ones from place to place, crushes the small ones into very very small fragments, which are then picked up by the coastal current and carried away with them. Once again the cliff is deprived of protection, and the sea resumes its attack on land.

Animals not only live in this dangerous zone of destruction, but also contribute to it. Sea borers are bivalves that live in soft rocks like limestones or sandstones. The valves of their shells are connected not by ligaments, but by a kind of hinge. The mollusk puts out a fleshy leg from one end of the shell, attaches itself to the rock, and then presses the jagged edges of the valves to its surface and, swaying from side to side, scrapes the stone alternately with one or the other valve. Very slowly, a small hole turns into a tunnel up to thirty centimeters long, at the far end of which the driller is located, extending two connected siphons along the stone corridor outward, in order to suck in and throw out water through them, in complete safety from the impacts of the stones played by the waves. But a quiet life continues only until the block of stone is so worn out that it falls apart into pieces. Then the driller should immediately start drilling a new tunnel, as long as it is intact.

Sea dates also climb into limestone, but not by drilling through them, but by dissolving the rock with acid. Their own shells, like those of any molluscs, consist of the same substance as limestone - calcium carbonate, and the acid would dissolve the shells at the same time, if they were not covered with a brownish stratum corneum, which gives them a resemblance to dates. The higher above the ebb line a marine organism lives, the greater the difficulties it faces: it stays out of the water longer between high tides, it can move more easily in the sun and receives more abundant doses of very unpleasant rain jets. This hazard scale has led to clear zones. Each is dominated by organisms best able to cope with this combination of difficulties, and therefore the rocky shores are striated in the most striking way.

Unlike silt, rocks offer plants a secure foothold, and rocky shores are usually clad in seaweed. At first glance, it may seem strange that in the sea there are no plants comparable in complexity to the flowering plants on land. But in the latter, a significant part of the tissues serves to solve problems that do not exist in the sea. A plant on land is forced to diligently absorb water, without which life is impossible, and distribute it to all parts of its body. It should pull the crown up so that competitors do not shade it, do not deprive it of the necessary share of sunlight. He needs the means by which the male and female cells are connected, and the means by which the seeds get to new places. And therefore, on land, plants acquired roots, stems, trunks, leaves, flowers and seeds. But in the sea all these problems are solved by water. It provides the algae with both support and all the moisture they need. She also transfers germ cells when they are released, and scatters spores. Since algae do not have vessels full of juice, the salinity of the water does not create any problems with the preservation of their internal fluids. Seaweeds, like all other plants, except for fungi, naturally need sunlight, and it does not penetrate particularly deep into the water column. Therefore, algae for the most part either swim freely or attach to the bottom, but where it is relatively shallow.

Just below the low tide, brown algae and kelp grow - they are very reminiscent of belts and in some places form dense masses of multi-meter ribbons swaying near the surface, where it is light. They firmly cling to stones with rhizoids, which, unlike the roots of land plants, do not have an absorption function and serve simply as anchors. These algae withstand some contact with air at especially low tides, but they cannot live closer to the coast. There, their place is taken by fucuses, smaller plants with gas bubbles in the blades, thanks to which they stay near the surface closer to the light. Fucuses of other species live even higher. The water is never deep there, and these fucus do without bubbles in short blades that do not need to be lifted. All these algae of the intertidal zone have a surface covered with mucus, which retains moisture for a long time and protects them from drying out. Species near the highest limit endure contact with air for four-fifths of the time. Many other types of algae also grow along the coast, but brown ones predominate almost everywhere and give each zone its characteristic appearance.

Some coastal animals also settle in certain zones. At the highest level, inaccessible even to the most unpretentious fucuses, where even the highest tide does not reach, and sea water enters only in the form of splashes, tiny sea acorns live. Attached to stones, tightly closing shell lids, these barnacles perfectly retain the very small amount of moisture they need inside. Their need for food is so small that they, incredibly, manage to extract sufficient nutrition from the spray.

Somewhat lower, the rocks are often surrounded by a dense bluish stripe of mussels. These mollusks are not able to stay in the air for as long as sea acorns, which defines the upper limit of their habitats. The lower one is set by starfish. The hunting techniques of these predators are straightforward, time-consuming, but destructive. The star climbs onto the mussel, clasps it with rays, along the lower edges of which there are suction cups, the so-called ambulacral legs. Slowly, slowly, the star opens the shell valves, protrudes the stomach from the oral cavity in the center of the body, presses it with a gasket to the soft parts of the mussel body, dissolves them and sucks them up. Starfish swarm on the sea floor just below the lowest tide line and devour various mollusks there. It is very difficult for mussels to survive in such conditions. But out of the water, starfish cannot feed, although they do not die in the air immediately, and therefore, half a meter above low tide, the conditions for the existence of mussels are already more favorable, and two or three meters above it, they completely take over the shore.

Mussels are attached to stones with a bundle of sticky threads, and where the surf is relatively strong, it is difficult for them to hold on. Then their place can be taken by relatives of sea acorns - sea ducks. Their body, the size of a large bean, is enclosed between calcareous plates, and they are securely held on stones with the help of a long, wrinkled stalk as thick as a little finger.

In this intertidal zone, next to mussels and sea ducks, there are many other animals that, however, do not occupy such a dominant position. Sea acorns, larger than their relatives in the splash zone, settle on mussel shells. They feed on nudibranch snails, mollusks without shells. In the recesses between the stones, where the water remains even at low tide, multicolored sea anemones wave their tentacles. Round sea urchins, bristly like pincushions, slowly crawl over the stones, scraping algae from them with teeth protruding from the mouth opening in the middle of their ventral side.

Although these zones with specific communities of animals and plants seem so clear-cut, and their boundaries so definite and strict, they can by no means be called permanent and unchanging. Their inhabitants are always ready to take advantage of the slightest opportunity to expand their territory. A strong storm is enough to pluck a couple of mussels - a bald spot forms in their continuous carpet. And here the waves can tear off their entire strips. And in the water there are always tiny fleets of larvae, both mussels and barnacles, just waiting for the opportunity to attach themselves somewhere. And it is likely that sea ducks will be able to capture a bridgehead in the territory of mussels.

On the northwest coast of America, a seaweed has developed a way of actively invading mussel banks. Its elastic half-meter stem ends with a corolla of curved slippery plates, giving it a resemblance to a miniature palm tree. This peculiar crown allows algae to deal with mussels. In the spring, a young algae, thanks to a happy coincidence, can cling to the mussel shell with this adaptation. In the summer, at low tide, the sea palm throws out spores that slide along the plates onto the surrounding mussels and get stuck between them. With the onset of autumn storms, waves that under normal circumstances did not cause much discomfort to mussels can fall under the crown of a palm tree and carry away the algae. Since the algae attaches to the shell more firmly than the mussel itself to the stone, it drags the mussel with it. Now young sea palms on a mussel bank get more space and quickly occupy the cleared stone with a new generation.

Taken individually, these inhabitants of the seashores cannot count on a long life. Sooner or later, the restless waves will crush the stones into powder. Shore currents pick up the fragments and carry them away, continuously sorting them by size, and then throw them off the lee side of some cape or line the bottom of the bay with them.

On such sandy shores, life is much poorer than in other places of the littoral - the border strip between sea and land. Here, each wave of each ebb and flow plows the surface of the sand for at least a few centimeters, so that the algae cannot gain a foothold. Therefore, herbivorous animals do not form communities there. And the rivers don't bring food supplies there twice a day. The edible particles that are left on the sand by the waves cannot provide food for any large animals, because the layers of sand act like filters in sedimentation tanks. The constant supply of oxygenated water to the sand allows bacteria to freely exist up to a certain depth. And they quickly decompose and absorb about 95% of all organic matter brought by the waves. Therefore, no worm is able to exist by eating sand, like worms in mantras - silt. The inhabitants of the sandy shore, extracting food from the water, must be ahead of the bacteria living in the sand.

Sabellida worms get out of the situation by gluing together a tube of grains of sand and fragments of shells, the end of which sticks out several centimeters above the sand, and protruding a whisk of tentacles from it to select edible particles suspended in water. For safety, marine cuttings are buried in the sand, but they expose two tubes above them into clear water and suck a stream through them into the filter between the wings. The mask crab leads a similar lifestyle. It does not have a fleshy siphon like molluscs do, so it constructs a suction tube by putting two antennae together. Some types of sea urchins also bury themselves in the sand. Their needles are much shorter than those of their relatives, the inhabitants of the rocky shores. With the help of these needles, they dig in, rotating them, as if on hinges, which makes these sea urchins look like miniature threshers. Having dug in, the hedgehog fastens the grains of sand around with mucus, thus constructing for itself a chamber with strong walls. Sea urchins, like starfish, have ambulacral tubular legs. In burrowing hedgehogs, a pair of legs is very lengthened, and the hedgehog exposes them through the sand. Cilia covering the legs drive water through the tubes, so that the hedgehog receives oxygen and edible particles dissolved in it through one, and spews waste through the second. These urchins hiding in the sand are rarely seen alive, but their beautiful whitewashed skeletons are often carried by the waves onto the beaches. A species that burrows relatively deep is heart-shaped, while those living closer to the surface are round and flat.

Most of the food on the beach - to the great inconvenience for so many marine animals - accumulates at the upper tide line, where the waves leave a large amount of all kinds of organic residues: scraps of brown algae and fucus plucked from rocks, jellyfish that the wind drove to the shore, dead fish , shellfish eggs - the terms change from high tide to high tide and from one season to another. Sea fleas - amphipods - get all the moisture they need from wet sand and hide for most of the day under wet heaps of algae thrown onto the beach. When the air cools with the onset of night, they get out - 25 thousand per square meter - and begin to destroy decaying plants and animal corpses. But they are the lucky exception. Most of the marine inhabitants of the beach are not able to get to these riches.

However, on the southern coast of Africa, one mollusc, the puddlefish, has perfected a very ingenious way to get to these hoards with a minimum of effort and with a minimum of risk. The snail lies buried in the sand near the ebb tide. As the tide rolls over her shelter, the plow crawls out of the sand and sucks water into her leg. The leg swells and takes a shape resembling a plowshare, although its function is closer to a surfboard - the wave carries it, and hence the snail, higher to the shore, lowering the mollusk onto the sand in the same place as its other cargo. This snail is very sensitive to the taste of decomposition products in water and, having found it, draws in its leg and crawls to where it is stronger. Around a dead jellyfish, dozens of plowfish gather in a matter of minutes. They immediately start eating until the tide reaches its highest point and their prey is surrounded by water. It is dangerous for them to be at the upper tide line: busy with food, they can miss the beginning of the ebb and stay on a dry shore. When the water rises higher, the plows leave their prey and burrow into the sand, from which they get out only at low tide, inflate their legs and roll down with the waves to a great depth, so that there they wait in the sand for the next tide.

Only a few marine animals are able to stay alive, having fallen beyond the upper limit of the tide. Turtles for such excursions are forced by their origin. Their ancestors lived on land and breathed the air. Over countless millennia, sea turtles have become excellent swimmers, learned to dive and stay under water for a long time, and their legs have changed into long wide flippers. But turtle eggs, like the eggs of all reptiles, can only develop in the air - the embryo needs gaseous oxygen, otherwise it will die. Therefore, every year, sexually mature female turtles, having mated in the ocean, must leave its safe expanses and get out on land.

Ridleys, perhaps the smallest of the sea turtles, at just over half a meter long, breed in colossal aggregations that are a most amazing sight. On two or three secluded beaches in Mexico and Costa Rica, for several nights between August and November (scientists have not yet learned how to determine the exact time), hundreds of thousands of turtles come out of the sea and crawl along the beach. The lungs and dense skin preserved from their ancestors do not allow them to either suffocate or dry out, but the flippers are poorly adapted for movement on land. However, nothing can stop the turtles. They crawl and crawl until they reach the top of the beach where the vegetation begins. There they begin to dig nesting holes. There are so many of them that they climb on top of each other, looking for a suitable place. Vigorously digging flippers throw sand at their neighbors, touching their shells. But now the hole is ready. The turtle lays about a hundred eggs in it, carefully fills them with sand and returns to the sea. This goes on for three or four nights, during which time up to a hundred thousand ridleys can visit one beach. The development of the embryo lasts forty-eight days, but often before the expiration of this period, new hordes of turtles appear on the beach. Again the sand is strewn with crawling reptiles. They also begin to dig holes, and many quite by accident destroy the nests of their predecessors. Leathery shells and decaying embryos are scattered all around. Only one egg out of five hundred goes through the entire development cycle, and a young turtle is selected into the world. And this is still a very good ratio.

The factors driving this massive oviposition have not yet been fully established. It is possible that Ridleys visit such a small number of beaches in such numbers only because they are brought there by currents. On the other hand, if they spread their landfalls more evenly throughout the year, large permanent populations of predators such as crabs, snakes, iguanas and kites would be concentrated near their beaches. In the present state of affairs on these beaches, the rest of the time there is so little food that turtles almost do not meet such enemies there. If this is the case, then such mass character is bearing fruit: in both the Pacific and Atlantic oceans, ridleys remain one of the most common turtles, while the number of other species has declined markedly, and some are threatened with complete extinction.

The largest of them all, the leatherback turtle reaches a length of over two meters and weighs more than half a ton. It differs from all other turtles in that its shell is not horny, but made of hard, like rubber, skin with longitudinal ridges. She lives in the open sea and leads a solitary lifestyle. In tropical seas, the leatherback turtle is found everywhere, but it was also caught far in the south - in Argentina and in the north - off the coast of Norway. Nesting beaches of this species were found only a quarter of a century ago. Two were found: on the east coast of the Malay Peninsula and in South America - in Suriname. Both leatherback turtles are chosen to lay eggs during the three-month season, several dozen individuals in one night.

Females usually appear in the dark at high tide when the moon rises. A dark hillock appears in the waves of the surf, gleaming in the moonlight. Leaning on huge flippers, the turtle gets out on wet sand. Every few minutes she stops to rest. It takes her at least half an hour to crawl to a sufficient height, since the nest should be out of reach of the waves, and on the other hand, you can only dig in wet sand that does not crumble. Often the female finds a suitable place only after two or three unsuccessful trials. But even then she works with great zeal: from under the front fins, the sand flies back. Soon the wide hole becomes deep enough. Then, with careful and precise movements of the hind flipper, the female digs a narrow vertical tunnel in its bottom.

To the sounds carried by the air, she is practically deaf, and human voices do not disturb her. But shine a flashlight on her while she crawls along the beach, and she can return to the sea without laying eggs. When the nest is ready, even the brightest light will not make the female stop laying. Pressing her hind flippers to the sides of the ovipositor, she quickly, group by group, directs the white balls of eggs into the tunnel, sighing heavily and moaning. Mucus oozes from her large, shiny eyes. Half an hour later, all the eggs are laid, and the female carefully fills the hole, crushing the sand with her hind flippers. She usually does not return to the sea immediately, but crawls along the beach, sometimes starting to dig, as if she is trying to confuse the trail. In any case, by the time the female heads for the water, the beach behind her is so dug up that it is almost impossible to recognize the nests.

However, people spying on her do not particularly need to guess. In Malaysia and Suriname, during the season, every night from dusk to morning, the beach is observed, and eggs are removed from the nest almost directly from under the laying female. Currently, a tiny fraction of these eggs are bought by government organizations in order to breed turtles in incubators, while the lion's share of them is sold in local markets and eaten.

It is possible that we do not yet know all the nesting beaches of the leatherback turtle. Perhaps some of these sea travelers come ashore on some uninhabited islands and lay eggs there that are not disturbed by man. They do not travel alone. The inhabitants of the littoral, which, having become adults, can no longer move away from shallow waters, at earlier stages of their development managed to travel in the form of seeds and larvae, eggs and juveniles. And for them, the island may not be a densely populated place where competition is as great as on their native coast, but a haven that offers them the freedom to evolve into entirely new forms.

David Attenborough. LIVING PLANET. PUBLISHING HOUSE “MIR”. Moscow 1988

- August, 29th 2012

The diversity of marine life on a sandy bottom can hardly be compared with life literally seething among the underwater rocks. Here there is a place for algae bushes to gain a foothold, and among these dense thickets countless fish, crustaceans, and mollusks can hide and live. There are a lot of shelters here - caves, cracks, where you can wait out the storm and hide from predators.

Any solid surface in the sea is used repeatedly: an algae is fixed on a stone, other algae, sponges, bryozoans grow on it; someone else settles on them; tiny mollusks and various crustaceans crawl along the branches. Of course, life on rocks is much richer and brighter than sandy. And in order to see it, scuba gear is not needed, since its greatest diversity is not in the blue depths, but relatively shallow - up to 10m. So, knowing how to dive correctly with fins (or without), but without fail with a mask, you can easily see all the brightest and most wonderful.

There are more than a hundred species in the Black Sea. But the most important and numerous underwater thickets are formed by the main alga - brown - called bearded cystoseira. Its forests surround the shores of our sea wherever there is solid ground. This is exactly the algae that, after a storm, forms whole shafts along the beaches, smelling sharply of iodine - the very smell of the sea. Visitors to this pungent smell is not too to their liking, but it is so unusually memorable!

In these drying brown bales, one can see amphipods and other small crustaceans, familiar from the sandy shallows, very similar to wood lice. These are isopods, or isopods. They are also called spherols-watermelons, for the fact that they seem to “roll” among the stones of the beach and the passed grass. They not only look like wood lice - they are their closest relatives. Know that our ordinary gray ground woodlice are also isopods, and they must be respected simply for the antiquity of their kind (besides, they are completely harmless creatures). This unique crustacean has managed to reach the land completely and still lives on land with gills that are protected by a shell-cap.

The closest relatives of wood lice and isopods are sea cockroaches, but they have nothing to do with our land cockroaches. They just look a little like them in shape, and in color - grayish-transparent and very cute. Very small, unlike the North Sea "cockroaches" the size of a palm (!). They spend their whole quiet life among underwater algae and, like isopods and crustaceans, serve as orderlies. Thanks to all of them, the sea does not smell of decay. So in the sea there is no one unsympathetic, unnecessary, and everyone works to the best of their ability and ability for the benefit of their Big House. And we must not forget that we come to this House of Theirs as guests and behave with dignity and nobility, not outrageous, ruining and destroying everything in our path, but humanly. Have you forgotten how?

A few steps from the shore, among the stones and algae - shrimps - elegant palemons. They are very beautiful, almost transparent, with magnificent blue and orange bandages on the legs. If you sit quietly in the water next to them, you can see that the shrimp do not swim, but walk slowly, turning over their legs (and how can they not get confused in them ?!) - they are grazing: they nibble on young algae seedlings. But if the shrimp feels your presence, then in an instant it will fly away from you, like a spring, in an unknown direction. This jump is the work of a muscular abdomen and caudal fin. On the branches of coastal algae, a sea goat “grazes” - a tiny crustacean only 3-4 mm long - tender and transparent. Quite a large shrimp - speckled palemon. It is distinguished by many small specks and wide lobes on the muzzle. Palemon prefers slightly saline waters, therefore, as a rule, it is found near the mouths of rivers flowing into the Black Sea. It is there that the locals collect them in nets, so that later, no longer transparent, but red, boiled, they are sold along the beaches and streets of resort towns.

One of the typical inhabitants of the rocky coastline is crabs. It must be said that crabs, crayfish, shrimps, lobsters, lobsters - all these are the names of close relatives from the order of decapods - the most complex and highly organized crustaceans. Shrimps are called small crayfish, and crabs (this is the English word - crab) are crayfish that do not have a muscular abdomen with a fin (therefore they cannot jump back). Lobsters and lobsters (French names) are large sea crayfish, and lobsters are the same, only in English. The body of crabs is flattened and shortened; the head and chest are covered with a carapace (shell) of a rectangular or oval shape. On the ventral side of the cephalothorax there are 5 pairs of legs, and the first pair is always with claws (the limbs of crabs are regenerated, that is, restored when lost, like the tails of lizards).

The very first on the rocky coast you can meet marble crabs. These are the only Black Sea crabs that run out of the water and travel along coastal rocks and rocks. However, at the first sign of danger, they instantly take off and rush into the water or the nearest gap. Because of their dark color and long legs, they are often referred to as spider crabs. They are small in size (no more than 4 cm) and you will not find them deeper than 5 m. If a marble crab is huddled in a slot, then you can’t pull it out of there for anything! Yes, and it’s not worth it - it can bite quite strongly with sharp claws. If you still caught a crab, then hold it by the sides of the shell at the back. And then it's better to let go - you should not make fun out of a living being. There is nothing special in the Black Sea crabs because of their small size.

Another notable crab is lilac, or water-loving. It is slower and more inconspicuous than marble, and is found not only in shallow water, but at depths up to 15m. He has an unusual ability to dig into the ground and stay there for no reason for weeks (!) With such habits, perhaps you can call him a water-loving philosopher. Otherwise, what else can you do with practically no food and air, how not to philosophize? There is another mystery of lilac crabs - their massive kills. They can happen both in summer and in autumn, and then their small stiff bodies dot the whole coast. Maybe some kind of disease, unknown to other types of crabs, so overnight mows down their lilac rows, or maybe it's from their love for a solitary philosophy: "woe from wit" ...

Or here is such an amazing specimen - an invisible crab. Invisible - because no one has yet been able to see him among the algae (unless you fill a large basin of water with algae and “calculate” him by moving among them). He himself is rather thin, with long legs, and at the same time he is also an amateur gardener - he plants various small algae bushes on himself to disguise himself. Yes, and walks like a flower bed among the grass - go and see.

The largest crabs of the Black Sea are stone (7-8 cm wide). They prefer to live deeper, although they are often found not far from the coast, but this is only in deserted rocky places. If all benthic crustaceans are primarily scavengers (according to the nature of their diet), then the stone crab, strong and aggressive, can be a fast and agile predator. In ambush, he lies in wait for snails, worms and small fish. Its claws have monstrous strength - they bite, like seeds, shells of mollusks and hermit crabs. Their muscle fibers at the molecular level differ from the muscles of animals and humans. In this we absolutely lose to them. The color of the stone crab's shell is always the same as that of the stones among which it lives. Basically, it is a red-brown color, but stone crabs living among yellow sandstones are themselves quite light. They are quite pugnacious among themselves: they fight for territory or prey up to the loss of claws (among the stones you can often see their separately-rolling fighting organs).

It looks like a stone hairy crab, only its size is half as large. And the shell of a dark purple color is covered with a thick layer of yellowish bristles-hairs. It lives closer to the shore, under rocks. Its diet is not too different from other crabs, but it is especially dangerous for various gastropod mollusks - like nuts, their strong shells prick, only fragments fly.

We also have a very small crab - a pea crab. Usually he lives among mussels, sometimes even inside the shell of a live mollusk (!). But you can find them on the stones of shallow water, only it is very difficult to see them - they are the size of a child's fingernail.

Remember, we talked about hermits-diogenes, who prefer the sandy bottom to the stones? So here, in the stone underwater kingdom, there is a kind of hermit crabs - klibanaria. He is several times larger than Diogenes and chooses for himself not small shells of nana or tricia, but empty shells of rapans. Rapanas, like all mollusks, move rather slowly along the bottom, but if you see that one of them is literally rushing over the stones, then grab it and look rather - you will surely see our wonderful Klibanaria. He is stunningly handsome, like an inhabitant of a coral reef - bright red legs and mustaches and the same red, but also with white polka dots claws!

Another small crab lives on underwater rocks (shell width is not more than 2 cm). He lives among mussels and has a deep pink color with an orange underbelly. His whole shell and paws are studded, as if with light hard moss, with numerous outgrowths. That's what it's called, the moss-legged crab.

If in the sand we met burrows of mole crayfish, then in the biocenosis of stones there is a “filterer” (filtering is such an unusual way of feeding) - the crab-like crayfish of pisidia. He sits under the stones, clinging to them, and waves his paws, forcing water with all kinds of food under the stone - he feeds like that, preferring not to go for food himself, but for her to go to him, and, I suppose, at the same time he says: “according to pike command, at my will ... "

The stones are overgrown - also the kingdom of gastropod mollusks - armored and nudibranchs. Nudibranch mollusks do not have shells and rather resemble slugs crawling along algae branches. There are few of them, but the world of shellfish is very diverse. Who has not collected entire collections of shells along the seashore as souvenirs before leaving home? But all this is empty houses of mollusks. The way of life of all of them is very similar: almost all of them eat with the help of a radula - a special grater tongue, with which they scrape their food from stones and algae stems (almost everything is eaten). There are also those who, having opened their shells, are waiting for someone of the right size to grab it and digest it. There are quite a lot of them all, but the most known to us are those whom we ourselves are not averse to eating, namely: mussels and rapana. The large and beautiful gastropod mollusk rapana is already quite familiar to us (its lacquered shells of various calibers are sold in all souvenir shops), in fact, it appeared relatively recently (about 60 years ago) and arrived from the Far East with ballast water ships. Brought it to us on our head!

Since then, many settlements of the bivalve mussel, our other edible mollusk, have suffered greatly. After all, the rapana is a cruel predator that paralyzes its victims with poison and eats away their bodies with its proboscis. The villain prefers mussels, although he also attacks oysters, scallops, cockles and even crabs. The meat of the rapana itself is quite tough and the longer you cook it, the more “rubber” it becomes - not like, in my opinion, tender tasty mussels. And it would be absolutely impossible for us and such a neighbor to be left without mussels, but smart people came up with the idea of ​​growing them on special marine farms, especially since mussels breed all year round, releasing a huge number of planktonic larvae into the water. And their nutritional qualities are only slightly inferior to the famous oysters. Mussels live in mass settlements - "brushes". On any solid object in the sea (on a stone, on piles under bridges), you can see their dark wedge-shaped valves attached to the surface with a bundle of thin threads - byssus.

It is remarkable that mussels are the most active filterers of sea water: they receive oxygen and food (phytoplankton) by passing water through their mantle. One large mussel filters 3.5 liters of water per hour. Can you imagine how clean the water along the coast would be if there were enough of these mollusks in it? Almost everyone knows mussels, but not everyone knows the chiton - another shellfish. The tunic sits on its “leg”, breathes through gills and feeds with the help of a radula. Its calcareous shell consists of 8 separate scutes with a crest-keel in the middle. For them, our sea is rather fresh, so they do not grow more than 15 mm in our country. And there is one eccentric among the mollusks called petrikola. So during his lifetime he voluntarily puts himself in a cell and lives in it until the end of his days as a prisoner. Petrikola the Prisoner, that's what we'll call him. This mollusk pickles minks in limestone with its acid secretions, settles there, and then, as it grows, only expands the chamber, leaving the entrance narrow (no entry, no exit). Its ribbed uneven doors remain inside even after the death of the inhabitant.

Isn't it all wonders of the underwater world?! - I'll ask you. Maybe someone will not agree, but it will be just out of harm;))

Extreme life - questions and answers in our material.

Is there life on sea ice?

Despite the cold and ice, many living creatures live in the polar regions. Mammals such as walrus, sea dog and many whales live in the Arctic. Whites, for example, hunt on the Arctic ice for ringed seals, which they watch for near ice holes. There are no land predators in Antarctica. However, thousands of penguins live here, spending most of the year on the frozen continent or on ice blocks in the sea.

What are the living conditions on the coast?

We know that seashores look different. There are flat shores with sandy and pebbly beaches, steep rocky and swampy shores. Since the conditions on them differ, each coastal form presents its own separate habitat for living beings.

What living creatures live on rocky shores?

On the rocky coasts, the conditions for life are quite harsh: the animals and plants living here are forced to fight the surf, experience the effects of heat, cold and salty winds. Nevertheless, they have a huge number of living creatures - algae, molluscs, sea anemones, sea acorns and sea snails that live on the rocky bottom. The stagnant waters are home to starfish, shrimp, crabs and small fish. Of the plants, algae are the most common.

What do the animals on the rocky shores eat?

Sponges, sea acorns and sea anemones feed on what the surf brings. Snails eat algae growing on rocks, while trumpeter clams drill holes in the shells of other mollusks and eat their meat.

What birds are found on the rocks?

Puffins, common and herring gulls live on the rocky shores. And such birds as storm-petrels, petrels and kittiwakes come here only to make nests. Since the steep banks are very often inaccessible to predators, they settle here with their offspring in whole colonies.

What animals live on sandy and pebbly beaches?

Only a few species of animals are able to live on sandy and pebble beaches. The waves constantly roll over the pebbles, the sand dries in the sun, is blown away by the wind and cannot provide protection. Only invertebrates (animals without an internal skeleton) can adapt to these conditions, which is why millions of molluscs, worms, crayfish, crabs, sea urchins and starfish live here.

How do sandworms hide?

It is difficult to meet animals while walking along the beach. However, if you pay attention, you will see tiny holes in the sand, holes and mounds that indicate that someone lives here. For example, the sandworm lives in a U-shaped funnel, the depth of which can reach 40 centimeters. It feeds on sand, digests nutrient particles, and throws the remains to the surface. During low tides, lumps of feces can be seen, which indicate the presence of a sandworm.

What is special about atherine fish?

These thin silvery fish live off the coast of warm seas. From March to September, females spawn on the beaches. They wait until the strong waves of the surf carry them to the sandy shore at night. Tiny eggs have small appendages with which they cling to aquatic plants and hang on them until small fish appear.

How does a sand crab live?

The length of the sand crab is only 4.5 centimeters, it digs complex passages and minks in the sea soil, the depth of which reaches 50 centimeters. When the sand crab burrows into the soil, it draws in water with its long antennae and uses the oxygen it contains.

How are sand dwellers protected?

There are practically no stones on sandy beaches under which animals would find protection.

Therefore, most of their inhabitants defend themselves by burrowing into the sand. However, this does not always help, because during high tides, fish come to the shore and swallow everything they see. And at low tides, sand dwellers become victims of coastal birds, which pull them out of the sand with their long beaks.

What do the scabbards look like?

These live in muddy soils. They got their name from the shape of the shells. The length of these animals in the North Sea reaches 17 centimeters, and in North America - 25. "Sheath" live in deep holes in the sand and stand upright, "upside down." Behind them are two short tubes - "input" and "output". During high tides, bivalves emerge from the sand to filter out the plankton.

How do plants manage to grow in the dunes?

The dunes are an inhospitable habitat that is in constant motion. Plants living here have to endure drought, wind, salt and sea foam. The dunes grow grasses with long roots, well adapted to quicksand. They strengthen the soil, as a result of which other plants can grow here: for example, seaside eryngium, couch grass or sea mustard.

What animals live in the dunes?

The dunes are home to many species of animals that can tolerate the heat and dry climate well. Wind and sea foam do not harm them. To escape the heat, most of them are active only at night. In the dunes there are moles, scarab beetles, hedgehogs and lizards, as well as wild rabbits, red foxes.

What are salters?

Soleros is a salt-loving plant with a fleshy, thick trunk that looks like a cactus. He is one of the first to settle in the marshy soil of the sea coast. Saltwort can be eaten. It is best to marinate them, then they acquire the most pleasant taste. Very young plants are so tender that they can be eaten raw, like a salad.

Do animals live in saline meadows?

Although, at first glance, it will seem strange - saline meadows are the habitat of many animals. Their deepest (usually flooded) areas are especially rich in plankton. Many worms, mollusks, crabs and fish live here. Insects and spiders live in salty meadows located further from the sea. In addition, these places are the habitat of coastal birds, which, with their long beaks, look for food in the swamp.

How do plants survive in saline grasslands?

There is a lot of salt in saline meadows, so the plants that grow here are called salt-loving, or solonchak. Unlike other plants, they do not experience problems with salt. Most require salty soil to grow at all (eg, salt marsh asters and salt marsh plantains). Plants have adapted to their environment in different ways. Some, in order to survive in these places, remove the salt they get from the soil through special glands in the leaves; others save it in stems and leaves, which they shed when their growth time is over.

Who is a sea mouse?

Marine is a shallow-water polychaete annelids up to 20 centimeters long. It lives in the silt of the North Sea. The body of the worm is covered with iridescent bristles that prevent silt from entering the animal's respiratory system. The sea mouse feeds mainly on carrion.

What birds are called coastal?

Coastal birds include many bird families with the same characteristics: they are all long-legged and have long beaks. As a rule, they roam in shallow fresh and salt waters.

or live in swamps. Coastal birds include oystercatcher, plover, and snipe.

How do mangrove trees reproduce?

Mangrove trees reproduce in a strange way: they are viviparous plants - their seeds germinate right on the tree. The sprout, or seedling, has a bulb-shaped root and reaches a length of 30 centimeters. In the end, the sprout falls off and sinks into the silt, where it takes root. This is how a new tree appears!

Who is a "crab eater"?

You probably won’t believe it, but the “crabeater” is the name given to the long-tailed macaque that lives in the mangrove swamps of Southeast Asia. In fact, these monkeys are omnivorous (eat fruits, leaves, insects), but their main food is crabs and shellfish. As a rule, they climb down from the trees and catch a treat from the water. Hence their name.

What's unusual about mudskippers?

The mudskipper is the only fish that can live both in water and on land. Its feature is that it can breathe on land, because at low tide its gill slit closes. In addition, this fish, with the help of thick pectoral fins, can crawl on muddy soil and even climb trees. The mudskipper lives in mangrove swamps, between mangrove roots, in muddy soil. There he looks for small crustaceans and worms.

Where did the fiddler crab get its name from?

Fiddler crabs live on beaches and in tropical mangrove swamps deep in the sand or silt. Males have claws of different sizes. They use a large claw to attract a female or threaten an opponent. Since they seem to be beckoning, these crabs are called "beckoning". If during the battle he loses his large claw, a new one appears in its place, and the other, small one, increases.

Extreme life in nature - questions and answers

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Aquariums and Malawian cichlids, modern aquarium design: on our website

ANNOTATION

The extraordinary rise and fascination with cichlids in the early seventies of the world aquarism owes the appearance of the Malawian cichlids of the “Mbuna” group, which received this name from local fishermen. The inhabitants of the rocky shores of Lake Malawi, feeding mainly on algae, a lush carpet covering rocks and stone placers to a depth of 20 meters, were distinguished by an exceptionally bright color that competed with coral fish.

Subsequently, many hundreds of other species of Malawian cichlids and their geographical races have appeared among aquarium lovers. The amazing beauty and brightness of the Malawian cichlids provokes lovers to create arrangements with live plants such as the so-called Dutch aquarium, which is completely different from natural biotopes.

Based on the author's many years of practice, practical recommendations are given to reduce the problems of caring for fish to a minimum, completely surrendering to observing the unique intellectual habits of cichlids, whether it's just content for decorating the interior, their mating games, reproduction or offspring care.

Introduction

The first wave of Malawian cichlid fascination swept the aquarium world only 30 - 40 years ago. Since the beginning of the 70s, Malawians have appeared in our country. Their popularity among Russians does not decrease even now - more than 100 species of strong, beautifully colored fish with the most interesting behavior, like all cichlids, inhabit our domestic reservoirs.

Lake Malawi, or as it was called before - Nyasa is located in the southernmost part of the African rift. - So, in scientific terms, they call a break in the earth's crust, thanks to which the deepest lakes of East Africa - Victoria, Tanganyika, Malawi, as well as the Siberian pearl of Russia - Lake Baikal were formed.

According to the latest data (June 2003, M.C. Oliver), 343 cichlid species belonging to 56 genera live in Lake Malawi. The vast majority of these fish are endemic, that is, they are not found anywhere else. Only 4-6 species of cichlids belonging to the genera - Astatotilapia, Oreochromis, Pseudocrenilabrus, Serranochromis, Tilapia (according to various authors) are also found in other African water bodies. A few hundred more species are known to aquarium lovers and specialists, but have not yet found their scientific description. Moreover, as new areas of the lake and its deep waters are explored, the latest species, subspecies and color forms of Malawian cichlids are becoming known.

According to the characteristics of nutrition and lifestyle in nature, Malawian cichlids are usually divided into two large groups:

1. Mbuna - a group of cichlids living near the rocky biotopes of the coastal part of the lake, near the islands and underwater reefs. The basis of the natural diet of these fish is algae covering stones and rocks with a continuous carpet, as well as various aquatic organisms hiding among these algae;

2. A complex of cichlids originating from haplochromis and inhabiting a wide variety of biotopes of the lake, including underwater caves, sandy ones, overgrown with higher aquatic vegetation, as well as transitional zones between rocks and sand. This also includes groups of Malawians under the names known to amateurs as “utaka”, “usipa”, etc.

Strictly speaking, the fossil ancestors of the Mbuna are also Haplochromis, but historically, this name, given by local fishermen in the Chitonga language, is so rooted in science and in the aquarium trade that now they have begun to gradually forget about it. It is the common ancestors for both groups that determine the characteristic way of reproduction of Malawian cichlids, in which females incubate eggs and larvae in their mouths for three weeks. During this period, female fish do without food and should not be provoked in an aquarium by throwing food in front of their noses. Carried away by food, hungry fish can spit out eggs or larvae, or even swallow them altogether. Many years of breeding experiments indicate that some females are not able to normally incubate eggs and quickly eat them. Therefore, in order to obtain offspring from such fish, it is necessary immediately after spawning to select eggs from females and incubate them artificially in incubators. The development of eggs, larvae and characteristic developmental defects are shown in the photographs. It is interesting to note that the size of eggs in different species is also different. Moreover, it was possible to establish that the same females are able to spawn different sizes depending on the diet, and the ratio of males and females in future offspring also largely depends on the conditions of keeping and feeding the fish in the aquarium. Frightened when catching and transporting fish, they sharply lose their brightness, which is almost a natural phenomenon for cichlids, so their true color can only be judged by adult active specimens grown using vitamin-rich feed and in a calm environment. If stronger territorial fish live in the neighborhood, Malawian cichlid juveniles may never reach the color characteristic of the species at all, and the only way to solve the problem is to plant a group of fish weakened by constant stress of oppression separately. Here, normal coloration can be expected within a few days.

The apogee of the manifestation of the vital activity of fish and the development of secondary sexual characteristics associated with this - elongation of the fins, an increase in brightness and stabilization of color, the development of a fat pad in the forehead in males, etc., is the repeated participation of fish in reproduction. The resulting cycles of mate selection, territory acquisition and defense, clearing of the presumed spawning site (or sites), pre-spawning games with a demonstration of strength and beauty, spawning itself and the complex of most active actions determined by this - contribute to the development of color and , so to speak, the self-affirmation of males and females, as the true owners in the aquarium. The fancier should also not forget that the female "Mbuna", as well as the males, are territorial and armed with sharp grater teeth, allowing them to scrape algae from rocks, and they will not miss the opportunity to use them in defense and attack, if it is a question of expulsion. from its territory of a potential invader. That is why it is impossible to recommend the combination of females engaged in incubation of eggs in the mouth in small aquariums.

Aquarium device

All cichlids of the African Great Lakes, including Malawians, are very similar in terms of water properties and conditions in the aquarium. Slightly alkaline (pH 7.5 - 8.5), medium hardness or hard water with a temperature of 25-27 degrees, suits most species, however, there are also their own characteristics for the inhabitants of each lake and group of fish.

Regular water changes (the more the better!) or sophisticated filtration and regeneration systems, including mechanical, biological and chemical filter elements (preferably the use of activated carbon), allow you to minimize the problems of caring for fish, completely devoting yourself to observing the unique intellectual antics of your pets. Whether it's just keeping cichlids for beauty, their mating games, breeding or caring for offspring. The long-term practice of the author, regarding the aquarium maintenance of cichlids of the African Great Lakes, has shown that adding 60-80 g of sea (in extreme cases, ordinary table) salt and 5-6 teaspoons of baking soda per 100 liters of water to water has a beneficial effect on fish . At the same time, a stable biological regime is established in the aquarium with a slightly alkaline pH reaction with water. It is desirable to maintain rigidity within 8-15 degrees and avoid sudden jumps in hydrochemical parameters when changing water.

An aquarium for keeping adult Malawian cichlids should be as large as possible. The minimum size is 1 m with a capacity of at least 200 liters. Be sure to have a large number of shelters for fish, as well as a free area for swimming. For decoration, as a rule, large stones and plastic imitations of caves are used. It is very important that the shelters are located along the entire height of the aquarium from the bottom to the very surface of the water, which allows to some extent to divide the territories by “floors”. If the size of the aquarium is minimal, shelters should be located along the entire back wall at a certain distance from it (usually 5-8 cm), allowing the fish to maneuver freely, moving from “floor” to “floor”.

Coarse sand and several flat stones are laid at the bottom, which can be used by the inhabitants as spawning grounds. Fish love bright light and slightly alkaline water of medium hardness. The optimum temperature is 27 degrees. The properties of natural waters can be briefly characterized by high transparency (up to 17-20 meters), pH 7.7 - 8.6 and electrical conductivity of 210 - 235 microsiemens per centimeter, at a temperature of 20 degrees. A constantly running filter and powerful water aeration are a must. As mentioned above, the most important condition for well-being is regular water changes - twice a week, 25% of the volume of the aquarium gives good results. Water for replacement is obtained by mixing hot and cold tap water, with the addition of a chlorine-neutralizing agent, such as “Chlorine-minus”, salt and baking soda. It is quite possible to keep a “duck” in a Dutch aquarium slightly modified with a few stones at the bottom, filled with numerous plants. Obviously, in this case, salt and soda additives are harmful (for aquatic vegetation). It should also be borne in mind that some types of cichlids are very partial to certain types of plants. For example, Livingston's nimbochromis and polystigma with obvious pleasure (and in large quantities!) Eat vallisneria. At the same time, you can arrange an aquarium in such a way and pick up cichlid communities and live plants that it will simply be impossible to take your eyes off it.

Malawian aquarium with live plants

The amazing beauty and brightness of Malawian cichlids provokes amateurs to create aquarium arrangements that are completely different from natural biotopes. The first to succumb to this temptation were our German colleagues, as well as cichlid lovers from Holland. Following this, the cichlids of other European countries picked up the baton, including the countries of the former Eastern bloc - Poland, Hungary, Czechoslovakia. The huge popularity of the Malawian cichlids in Europe, in my opinion, arose. It should be noted that overseas arrangement of an aquarium with cichlids, similar to the Dutch one, did not find a sufficient number of supporters. Even the most recent publications in American magazines (for 2000 - 2003) testify to the commitment to the traditional decoration of the aquarium with stones, driftwood and plastic crafts.

In Japan, the developed countries of Southeast Asia and Australia, I also did not notice a clear interest in the system of decorating cichlid aquariums with live aquatic plants. Of the cichlids in the natural aquariums of Takashi Amano, you can only see butterfly chromis and apistograms. The variety of representatives of the underwater flora in African lakes is small and includes only a few species of plants belonging to the genera of pondweeds (Potamogeton), vallisneria and nymphs. It is these plants that should decorate aquariums-bitops (see the book "Aquarium. Design and care device"). African anubias plants, often used by amateurs to decorate aquariums, are not found in the natural biotopes of water bodies in East Africa, but they are well suited for such water bodies due to their durability and hard leaves.

As is known, the main food of the Mbuna group cichlids is algae, violently covering rocks and underwater placers of stones, as well as aquatic organisms that live in this underwater carpet or near it. In other words, fish feed mainly on plant food, that is, plants. On the other hand, at depths of more than 20 meters, the amount of light becomes less and less and, in the end, it will be clearly insufficient for algae and, moreover, for higher aquatic vegetation. Therefore, in fish living at great depths, the share of plant food in the diet will be the smaller, the deeper they live in natural biotopes. Of particular interest in this sense are the inhabitants of underwater caves and grottoes. There, even at shallow depths of several meters, there is clearly not enough light for aquatic vegetation.

As it was possible to find out from the study of books and articles by E. Koenigs, G.-I. Herrmann, A. Ribbink, A. Shpreynat and others, from watching a number of videos, as well as personal conversations with the authors of underwater field observations, the most promising in this regard will be, first of all, representatives of the genera Aulonokara, Otofarinx, as well as plankton-eating haplochromids (Utaka) among the cichlids of Lake Malawi.

In addition to the above features of the diet of cichlids, another problem becomes obvious - the problem of the suitability of the living conditions of aquatic plants in terms of water mineralization (especially its hardness) and pH.

It is known that the water in the African Great Lakes is slightly alkaline - pH 7.6 - 9.0. It is desirable to create the same conditions in the aquarium. However, reference books on aquatic plants usually indicate that pH 7.5 is almost the upper limit of the active reaction for their normal growth. At higher pH values, it is very difficult to provide sufficient levels of carbon dioxide in the water necessary for the assimilation and growth of aquatic vegetation. According to this, it became clear that the Malawian water is not very suitable for aquatic plants - so you need to accustom the fish ?? - Not at all. The experience of growing aquatic plants in artesian water suggests that it is easier to accustom plants to such a hydrochemical regime.

In terms of lighting, there are usually no problems, since both fish and plants love bright daylight. Experience shows that commercially available metal halide lamps with natural color rendering are best suited for this. However, ordinary daylight fluorescent tubes are quite suitable for fish and plants, as long as the fish look beautiful and the plants have enough brightness. As practice shows, when creating a Malawian aquarium with live plants, it is only important to avoid typical mistakes.

Let's imagine that in a traditional Malawian aquarium with shelters made of only stones, you plant a twig of sinnema or hygrophila. What will happen? The answer is obvious - it will simply be eaten in the next hours, or even minutes.

If you plant a “tasteless” cryptocarina, for example, Cr. pontederifolia or nymphaeum, they are unlikely to be eaten, but most likely spoiled. They will gnaw through the leaves, taste the petioles ... Well, what if you plant hard-leaved echinodorus, anubias? Most likely they will also be slightly spoiled. - In some places they will gnaw to holes, in some places they will try to bite.

But then why do cichlids practically do not touch them in an aquarium with lush thickets of aquatic vegetation? Unclear.

The situation seems hopeless, but then what to do? The answer is simple - to teach the fish not to touch the plants. How to do this will be discussed below. Or maybe such plants are known that fish do not eat at all and do not spoil? Yes, there are, for example, some types of rotala (in more detail these and other plants will be described in the book "The World of Aquatic Plants", which is being prepared for release).

More than once I had to observe bewilderment among my new visitors - connoisseurs of aquatic plants. Disputes most often arose just at aquariums with Malawian and Tanganyika cichlids. Some said - reinforcement, others a new fern, others ulvaceus ... In fact, these were most often ordinary garden crops tied to a pebble - spinach, lettuce, celery in all their numerous varieties. The fact is that all newly arrived cichlids were accustomed in this way to a plant-based diet. Experience shows that no matter how “good” so-called balanced fish foods are, they still lack one or another component in the daily diet. Having satisfied their need for vitamins and microelements in this way, cichlids begin to pay little attention to most ornamental aquatic plants (they are not as rich in useful substances as, for example, spinach), and spend all their energy on sorting out relations with their fellows. In this case, the color of the fish becomes truly irresistible. I’ll tell you a secret that at first, due to a lack of vitamins in the diet, they also gnawed and spoiled the plants. Indeed, even on African aquarium farms, fish are fed for a long time with dry food or their local substitutes before being sent. The basis of these substitutes is most often flour. There is no need to talk about vitamins and microelements here. If such fish are placed in an aquarium with live plants, then this vegetation will not be good. If you do not have time to teach fish not to eat plants, you should definitely be guided by the main rule - there should be a lot of plants and they should be fully developed. Only in this case, the fish will not destroy them all at once, in addition, some inevitable losses in the foliage will not be so noticeable.

Planting small cuttings in the hope that they will grow over time is a waste of time and money. At best, only gnawed "sticks" will remain in the aquarium. From all the above, the conclusion suggests itself - isn't it easiest to introduce African cichlids to plants at a very early age? Quite right. When breeding African cichlids, this is exactly what I do: I always put aquatic plants with the fry from a very young age. Most often it is Javanese moss, hygrophila and ceratopteris fern. With good lighting, these plants not only serve as an excellent top dressing due to biological fouling and an abundance of soft young leaves, but, in addition, purify water from pollution, being a kind of living filter. True, Javanese moss has to be periodically (usually once a week) taken out of the nursery aquarium and washed, since there is a lot of dirt on it.

As the fry grow, they have to be transferred to larger aquariums, where I usually grow echinodorus, microzorium, wallisneria, ludwigia and large species of hygrophila. Years of experience have shown that Hygrophila is the key plant in cichlid aquariums. Fish like it very much because it probably contains a lot of useful substances. With a wide variety of species and forms, these plants, in addition, are a wonderful decoration of the aquarium. With a lack of nutrients in the water or substrate, these plants often lighten or turn yellow a little, which makes them even more attractive.

And now let's look at the characteristic representatives of the Malawian cichlids from the two groups mentioned above, as well as the basic rules for keeping these fish in the most favorable conditions.

Mbuna group.

The extraordinary rise and fascination with cichlids in the early seventies is due to the appearance of the Malawian cichlids of the “Mbuna” group, which received this name from local fishermen. The inhabitants of the rocky shores of Lake Malawi, feeding mainly on algae, a lush carpet covering rocks and stone placers to a depth of 20 meters, were distinguished by an exceptionally bright color that competed with coral fish. The most popular among “Mbuna” were representatives of the following genera: cynotilapia - Cynotilapia Regan, 1921, iodotropheus - Iodotropheus Oliver et Loiselle, 1972, labeotropheus - Labeotropheus Ahl, 1927, labidochromis - Labidochromis Trewavas, 1935, melanochromis - Melanochromis Trewavas, 1935 - petrotilapia Petrotilapia Trewavas, 1935 and pseudotropheus - Pseudotropheus Regan, 1921.

It should also be noted that in modern literature, 2 more genera of cichlids of the mbuna group are additionally represented - Maylandia Maylandia Meyer & Foerster, 1984 (synonymous - metriaclima Stauffer, Bowers, Kellogg & McKaye, (1997) and tropheops - Tropheops Trewavas, 1984. Both of these The genera were originally proposed as subgenera of the Pseudotropheus group.Each of these genera includes more than 50 species and variations of cichlids.

It turned out that by carefully selecting the communities of these vegetarian fish in terms of size, color, and temperament, it is possible to create solid collections in one large aquarium, the structure of which was described above. Instead of algae, lettuce, spinach, dandelion and even parsley leaves, steamed oats and peas, black and white bread, etc. can serve as food. Small additions of animal feed - coretra, daphnia, enchitra and bloodworm, high-protein dry feed (up to 20-30% of the total) - supplement the diet. Fish in the aquarium grow larger than in nature, and give numerous offspring.

With improper feeding, when animal foods predominate in the diet, it is not uncommon for fish to develop a disease specific to Mbuna. It is expressed first in the appearance of long whitish excrement, which, in the form of thick threads, dangle for a long time at the anus. In the future, the fish, as it were, swell up, refuse to feed, lie down on the bottom and soon die. The dissolution of metronidazole (aka Trichopolum) in the water of the aquarium helps to cure the fish at the rate of one tablet of 0.25 grams per 50 liters of water. To do this, it is very convenient to take two tablets at once and rub them between your fingers near the surface of the water somewhere near the sprayer so that the solution mixes better. Some fish come up and grab the falling particles of the medicine, but that's okay. Moreover, it has been noted that the dissolution of Trichopolum even stimulates spawning in cichlids. The filter should be turned off and aeration increased. On the fifth day, 50% of the water is changed, adding a medicine from the same calculation. Metronidazole can be bought at a regular pharmacy. At the end of the treatment, the appetite of the fish is restored, but in order to avoid a relapse, the cichlids should be transferred to a strict plant-based diet. A similar disease has been noted in other lake cichlids and is undoubtedly caused by the stress of inadequate feeding. As a preventive measure, it is recommended to feed fish with metronidazole once a month at the rate of 0.7 g of the drug per 100 g of feed.

Labeotropheus Trewavasae Fryer, 1956- one of the first Malawian cichlids that got into the aquariums of Russians. Under favorable conditions, the fish grow up to 18-20 cm, while the females are approximately 25% smaller. In nature, it is smaller, only rare males grow up to 13 - 14 cm. The habitat of labeotropheus in the lake is limited by the upper seven meters of rocky ridges, lushly overgrown with algae, where they find places for feeding, shelter and spawning grounds. Only occasionally individuals were observed at depths up to 40 meters. Males are exceptionally beautiful - blue in color with a bright orange to red dorsal fin. The females of the original form are grayish-yellow with dark speckles and spots, but the variation with orange females has gained the most popularity. These fish can be distinguished already at a very young age - females are orange-yellow, males are dark brown-gray. They are very territorial, especially during the mating season and need a large aquarium, preferably at least 1.5 meters long. Spawning is better in the cave, as it is noted that the fertilization of eggs occurs outside the oral cavity of the female and the fertilized eggs remain unprotected for a longer time. Three weeks later, the females release the fry in shallow water, where they further develop and grow in well-heated water. In conditions of aquarium cultivation at the age of 8 - 9 months, fish are already able to bear offspring.

Fuelleborn's labeotropheus - Labeotropheus fuelleborni Ahl, 1927 very polymorphic and impressive appearance. Depending on the habitat, individuals are found from dark blue to blue and from almost orange to bright yellow in black-brown spots of flowers. For the outgrowth of the nose characteristic of the genus, the fish also received the name cichlid-tapir. Under favorable conditions, the fish grow up to 18-20 cm, while the females are approximately 25% smaller. The habitat zone of labeotropheus in nature is limited by the upper seven meters of rocky ridges, lushly overgrown with algae, where they find places for feeding, shelter and spawning grounds. They are very territorial, especially during the mating season and need a large aquarium, preferably at least 1.5 meters long. Spawning is better in the cave, as it is noted that the fertilization of eggs occurs outside the oral cavity of the female and the fertilized eggs remain unprotected for a longer time. Three weeks later, the females release the fry in shallow water, where they further develop and grow in well-heated water. In conditions of aquarium cultivation at the age of 8 - 9 months, fish are already able to bear offspring.

Melanochromis auratus - Melanochromis auratus (Boulenger, 1897)- the most widespread species in Lake Malawi. It is found everywhere and does not have pronounced color variations, although specimens of more intense coloration have been noted for the islands of Maleri, Mbenji and Mumbo. In nature, they do not grow more than 10 cm, although individuals exceeding this size by one and a half times in aquariums are far from uncommon. Along with the labeotropheus and zebra, the auratus are the pioneers of the Malawian boom around the world. The coloration of males and females differs sharply and resembles a negative and a positive in a photograph. Active males are almost black with a creamy longitudinal stripe running along the body from head to tail. The dorsal fin and upper back are light yellowish in color with a bluish tint. Females, and especially fry, are very brightly colored. There are two longitudinal black stripes on a golden yellow background. One right in the middle of the body, the second in the upper torso. Almost the same stripe on the dorsal fin. This stripe runs down the center of the creamy dorsal fin. Both juveniles and adults look very impressive and therefore these fish are constantly present in the aquarium market, despite their pronounced viciousness and territoriality. Fish are omnivores, however, when feeding, more attention should be paid to vegetable top dressing, as fish are prone to protein poisoning due to overeating food of animal origin. Several species of melanochromis are known that are very similar to auratus, especially at an early age, such as Chipok's melanochromis (Melanochromis chipokae Johnson, 1975). The nature of these fish is about the same aggressive.

Iodotropheus – Iodotropheus sprengerae (Oliver & Loiselle, 1972). Small, growing in an aquarium up to 6 - 10 cm, the fish are close to cinotilapia in their habits and style of ritania. Males are brown-violet, head and upper back orange. Females are smaller, greyish-brown in color. Iodotropheus fry are very attractive. When fed with brine shrimp or spring red cyclops, they become a beautiful dark cherry color. Due to this feature, fish are of interest for commercial breeding and, therefore, they are not difficult to acquire from hobbyists. Iodotropheuses are very early maturing and sometimes begin to breed at a size of only 3.5 - 4 cm. The offspring, initially numbering only a few fry, can eventually reach up to 50 young fish. The fish are very fast and active and can spawn in almost any, even the smallest areas in the general Malawian aquarium. The iodotropheus that have entered the culture of aquarium breeding take their original origin from the island of Boadzulu, where they are found at depths from 3 to 40 meters. Recently, 2 more species of iodotropheus have been described.

Cynotilapia afra - Synotilapia afra (Guenther, 1893). appeared in Moscow in the mid-eighties simultaneously with several color forms. The behavior of the fish resembles the pseudotropheus zebra. However, their diet is dominated by all kinds of planktonic organisms. Males are more inclined to eat plant foods, since during the spawning period they are tied to small underwater caves, where spawning usually occurs, and they try not to move far from them, being content only, for the most part, scraping algae from the surrounding rocks and stones. Inactive males, juveniles and females of cynotilapia often gather in large flocks and gradually roam in the upper and middle parts of the underwater rocky biotopes, occasionally sailing into open waters. Near sandy biotopes and in Vallisneria thickets, they are quite rare. More than 10 color variations of cinotilapia are found in natural waters. Flitty's cynotilapia is occasionally found in our aquariums. Cynotilapia fleetii Bakker & Franzen, 1978. According to the catalog of A. Ufermann and co-authors, the name of Flitty's cynotilapia is purely commercial in nature and does not have a real scientific description. Flatty's Cynotilapia is indistinguishable from Psedotropheus Greshakei (Psedotropheus greshakei) in appearance, so it is possible that this name would be correct. Males are bright blue with a purple tint. Their dorsal fin is orange-yellow, in some specimens it is bright orange. Females and fry are much more modestly colored, which largely limited their popularity. The size in the aquarium is up to 15 cm, in nature it is almost twice as small.

Petrotilapia - Petrotilapia tridentiger Trewavas, 1935- one of the largest fish of the Mbuna group, reaching a length of 17 cm in natural conditions. Widely distributed and quite numerous throughout the lake. The main difference between these fish is the presence on the jaws of a kind of grater in the form of numerous small three-toothed teeth. In the lake, petrotilapia occupy the smallest rocky biotopes, where algae flourish, which form the basis of their nutrition. Males are bluish-gray with a metallic sheen. Females are somewhat smaller, brownish-yellow. Narrow dark stripes across the body complement the coloration of both sexes. The fry of petrotilapias are unprepossessing in color, so their content in the aquarium is the lot of mbuna lovers and collectors. There are 3 more species, as well as several subspecies and color options of petrotilapia, however, in all cases, their fry and females are rather modestly colored and the prospects for their mass appearance in amateur aquariums are small. However, in the composition of the Malawian aquarium, representatives of the genus petrotilapia undoubtedly attract attention and complement its originality, thanks to the unusual appearance of numerous small reddish teeth. In addition, as already mentioned above, these fish “scrape” stones and shelters, while located at a right angle to the substrate. The nature of petrotilapias cannot be called angelic, but they do not practice special aggressiveness and long-term pursuit of their prey. The maintenance, reproduction and development of eggs and juveniles is the same as in other representatives of the mbuna.

Maylandia Livingston -Maylandia (Pseudotropheus) livingstoni (Boulenger, 1899)- widely distributed throughout Lake Malawi, as well as in Lake Malombe located nearby on the south side. The main color of the fish is golden sand - it allows them to be well camouflaged on the sandy biotopes of lakes, where they spend most of their lives at depths of 5 to 25 meters. Several populations of this species are known, differing in their coloration and size. Males can reach 14 cm (even more in an aquarium). However, a natural form is known to the north of Monkey Bay, the size of which is half as large. These fish were previously assigned to another species, Maylandia (Ps.) lanisticola. Lanistikola was considered a shell pseudotropheus, since fry and adolescents of these fish were often found in the shells of the gastropod mollusk Lanistes. However, subsequent underwater observations and a more detailed study showed that individuals not ready for spawning are hiding in the shells. They just use them as hiding places. The fry, released by the females “for a walk” near the shells, probably also climb there. However, not a single case of a female incubating eggs in her mouth was found in the shell. It is interesting to note that under natural conditions these fish make certain migrations during the breeding season. Living most of the time on the sandy bottom and feeding there on small invertebrates and bottom sediments of a plant nature, during the spawning period, these fish approach the sand-rock transition zones, where spawning occurs. Apparently near the rock biotopes, the fish feel more secure. However, females incubating eggs again swim away to sandy substrates, where, subsequently, they release fry.

Melanochromis Johanna - Melanochromis johanni (Eccles, 1973) one of the most popular Malawian cichlids, distinguished by its exceptionally beautiful - yellow-orange coloring of fry and females. Males with the onset of puberty completely change their color, becoming blue-black with two bright bluish-blue stripes along the body. Such a transformation for mbuna is not uncommon, which, of course, causes understandable bewilderment among novice cichlid lovers. However, at an early age, it is quite difficult to distinguish between males and females. Other things being equal, the males are slightly larger and have more pronounced yellow specks-releasers, similar to eggs, on the anal fin. The size in nature does not exceed 8 cm, females are smaller.

Reproduction is the same as that of other Malawians. The females, which incubate the eggs for three weeks in their mouths, hide among the rocks in shallow water. The previously considered subspecies M. johanni with discontinuous longitudinal stripes is currently described as an independent species - Mel. Interruptus Johnson, 1975.

Likom's pearl – Melanochromis joanjohnsonae (Johnson, 1974)- previously these fish were assigned to the genus Labidochromis. The species name also changed and these fish were known as M. textilis and M. exasperatus. Grow up to 9 cm, females are smaller. Bright, including all colors and overflows of mother-of-pearl and pearls, the coloring forms the basis for females and juveniles. These females are very difficult to distinguish from female labidochromis females L. flavigulus, L. maculicauda, ​​L. strigosus and L. textilis. For adult active males, a bright blue color with sparkles is more characteristic. On the dorsal fin, a rather wide dark border is also characteristic of male labidochromis. In his book on cichlids and other fish of Lake Malawi, Ed Koenigs notes the increased aggressiveness of the males of this species, which demonstrate these qualities all year round. At the same time, they occupy a large area reaching 3 meters in diameter. Under natural conditions, fish feed on small invertebrates, looking for them among algae and in adjacent open waters. At first, these melanochromis were caught only off the island of Likoma, but subsequently they were settled off the western island of Tumbi, where they are now perfectly settled and have become quite ordinary fish, near their new home. Maintenance and reproduction, as in previous species. In aquarium conditions, Cyclops and Coretra serve as excellent food for them, providing a constant brightness of color, despite the fact that these fish are not too picky and eat everything.

Freiberg's labidochromis Labidochromis freibergi (Johnson, 1974)- this type of labidochromis, like iodotropheus, begins to multiply at an early age. The mouth of females is tiny and it is quite difficult to extract large eggs from there for artificial incubation. Unfortunately, due to the faded, unattractive coloration of juveniles, this species, like many other labidochromis, is extremely rare in our aquariums and only among Mbuna collectors. Females of many species are almost indistinguishable from each other. But the males of labidochromis are completely different from females and, often, are very brightly colored.

Pseudotropheus zebra - Pseudotropheus zebra (Boulenger, 1899)- one of three species of Malawian cichlids that first appeared in Russia in 1973. Differs in surprising polymorphism. Over 50 natural color variants are currently known. In modern literature, most of these variations are attributed to various species of the genus Maylandia mentioned above. Classical descriptions of zebra variations in the literature have received the following generally accepted designations:

BB - (Black Bars) - striped zebra; corresponds to the traditional form of coloration in males with dark transverse stripes on a pale blue background (now Maylandia zebra);

B - (Blue) - blue form;

W - (White) - white form;

OB - (Orange Blotch) - yellow-orange form with black-brown spots;

RB - (Red - Blue) - orange-red female and blue male, the so-called red zebra;

RR - (Red - Red) - red female and red male, the so-called double red zebra (now Maylandia estherae (Konigs, 1995).

Other color variations Ps. zebra is named, indicating, together with the designation of the area in the area where the capture was made. For example, the blue zebra from Maleri Island (Ps. zebra B Maleri Island); striped zebra Chilumba (Ps. sp. zebra BB Chilumba); golden zebra Kawanga (Ps. sp.”zebra gold” Kawanga), etc. The affiliation of certain color variations and local forms to the described new species of Maylandia has not yet been finally settled - many aquarium and natural hybrids have appeared. In addition, the color of fish is largely dependent on their age and condition. So, for example, fry of the classic striped zebra have a uniform grayish-brown color, which only at the age of 6-7 months begins to turn into striped in males and spotted in females; RB red zebra fry are brightly colored already at a young age, while females are orange-red, and males look dark gray and only become pale blue at sexual maturity.

Pseudotropheus M6- Pseudotropheus spec. "M6" - appeared among the first Malawians in the mid-seventies. At that time, many species of cichlids were not described and ended up in our aquariums with alphanumeric indices. M6 clearly belong to the group of one of the most beautiful species of pseudotropheus - Ps. elongatus Fryer, 1956. Despite their very attractive coloration and unique elongated shape, true elongatus did not take root in our aquariums due to excessive aggressiveness and nondescript coloration of juveniles. The huge variability of elongatus in Malawi (more than 25 color options) nevertheless led to the fact that some species or subspecies still found their place with us. So, for example, M6 presented by Koenigs as a variant of the elongatus from the island of Boadzulu - Ps. sp. "Elongatus Boadzulu" turned out not to be as vicious as a real elongatus. However, at the same time, the M6s are taller and therefore not as unique as the classic look. But their calmer character did its job and M6 no - no, and it is also found in cichlids. In nature, M6 rarely grows up to 8 cm, females are even a quarter smaller. But in an aquarium, on protein feed and in a calm environment, these fish grow almost 2 times larger. Keeping and breeding with some experience is not a problem.

Tropheops - Tropheops (Pseudotropheus) tropheops Regan, 1922- found in the lake near rocky biotopes almost everywhere. The natural size does not exceed 14 cm. In aquariums, it is often somewhat larger. Like the previous species, tropheops are surprisingly variable. Currently, at least 30 local forms and variations are known. The colors and their combinations reflect almost all the colors characteristic of the mbuna - from bright yellow with an orange tint to dark blue, almost black. Two- or three-color coloration is not uncommon. In addition, the ornament includes all kinds of specks and stripes. Males are larger than females and, as a rule, are brighter, more multicolored. All species and variations of the genus Tropheops (6 species) are recognized as typical representatives of rock cichlids of the Mbuna group. The basis of their nutrition in nature is almost exclusively formed by algal fouling and small planktonic organisms found among algae.

Group “Utaka” and related species.

A group of Malawian cichlids, inhabiting mainly coastal biotopes, as well as underwater “chirundu” reefs that do not reach the surface of the water and feed on zooplankton, is called “Utaka” by local fishermen. Previously, all these species were assigned to the genus Haplochromis - Haplochromis Hilgendorf, 1888, but the revisions of the last decades have made their own significant adjustments. Many species were discovered and described during the cichlid boom of the seventies and eighties. However, to date, Malawian novelties regularly appear in cichlidophiles around the world. In aquariums, large collections can be created by placing other close species of cichlids, similar in temperament, with representatives of the duck group, whose diet is based on small aquatic invertebrates and fish fry. In his home collection, in a more than modest apartment, the author in the early 80s managed to collect up to 50 species of these cichlids. Among the entire tropical variety in our aquariums there are representatives of the following genera: Aristochromis - Aristochromis Trewavas, 1935 (only 1 species); Astatotilapia - Astatotilapia (Guenther, 1894) (1 non-endemic species); Aulonocara - Aulonocara Regan, 1922 (21 species and many color variations); Baccochromis - Buccochromis Eccles & Trewavas, 1989 (7 species); Champsochromis - Champsochromis Boulenger, 1915 (2 species); Copadichromis - Copadichromis Eccles & Trewavas, 1989 (27 described species and many local forms); Cyrtocara - Cyrtocara Boulenger, 1902 only 1 species - blue dolphin); Dimidiochromis - Dimidiochromis Eccles & Trewavas, 1989 (4 species with color variations); Fossorochromis - Fossorochromis Eccles & Trewavas, 1989 (monotypic genus); Letrinops - Lethrinops Regan, 1922 (26 species); Mylochromis - Mylochromis Regan, 1922 (18 very similar species); Nimbochromis - Nimbochromis Eccles & Trewavas, 1989 (7 species); Otopharynx - Otopharynx Regan, 1920 (13 species); Placidochromis - Placidochromis Eccles & Trewavas, 1989 (8 species); Protomelas - Protomelas Eccles & Trewavas, 1989 (16 very variable species); Sciaenochromis - Sciaenochromis Eccles & Trewavas, 1989 (6 species of which 2 are sometimes classified in the genus mylochromis). The fish presented above, as a rule, are completely unsuitable for joint keeping. Representatives of another Malawian group - “Mbuna”, are distinguished by increased territoriality and, as a result, aggressiveness and are much more disposed to a vegetarian diet.

Aulonocara jacobfreibergi (Jonson, 1974) previously belonged to the genus Trematocranus - Trematocranus Trewavas, 1935. Among the first Malawian cichlids were brought by the author in 1976 under the name Trematocranus auditor and were the beginning of the cichlid craze in those years. Size up to 13 cm in nature, but, like most Malawians in the aquarium, grow much larger. Females are much (sometimes almost twice) smaller. Unfortunately, both females and juveniles of all aulonocara are very modestly colored grayish with metallic glints, which limits the commercial value of these fish, despite the exceptionally attractive coloration of adult males. - Few lovers are found to wait almost a year for these ugly ducklings to turn into beautiful swans.

Natural habitats are rocky biotopes in which spawning males occupy small underwater caves. Fish form many local races, markedly different from each other, along the entire length of the lake from south to north. Like all aulonokars, the method of obtaining food is very interesting - fish, obeying the underwater currents, seem to hover almost without movement, above the surface of the bottom covered with sand deposits, instantly rushing down, at the slightest stirring in the sand. Feeding in captivity does not pose any problems - the fish are omnivorous and eat almost any kind of live, dry and cooked food with equal pleasure. As with all African Great Lakes cichlids, tubifex feeding should be avoided to avoid disease.

Queen Nyassa - Aulonocara nyassae Regan, 1922- got its name for the majesty of movements, behavior and wonderful coloration of males with a characteristic red spot located directly behind the gill covers. Females and fry, as well as all other representatives of the genus, are painted very modestly. However, according to modern information, fish under this name have never been exported, and the fish described above most likely belongs to a different species - A. hueseri Meyer, Riehl et Zetsche, 1987. However, no one in Russia was engaged in strict scientific identification.

Golden Queen - Aulonocara baenschi Meyer & Riel, 1985 took its name from the first imported aulonocara that appeared among German aquarists in the early 70s, as Queen Nyassa (Kaiserbuntbarsch). Zaokensky cichlid lovers call these fish peacocks (Peacock Cichlid), which reflects both the brightness of the color of the aulonocara, and the characteristic movements of the tail and fins, like an opening fan or peacock's tail in the process of mating games or rivalry. Unlike the previous species, this species is known only from one large reef, located at a depth of about 18 meters, 5 kilometers from the village of Benga, opposite the Nkomo River (southern part of the lake). The natural size of the fish does not exceed 9 cm, in the aquarium they are noticeably larger. Spawning occurs year-round, both in nature and in the aquarium. Females incubate eggs in their mouths for 3 weeks at a temperature of 27 degrees.

Aulonocara stuartgranti Meyer & Riehl, 1985- occurs near the northwestern part of the lake shore in transitional zones of rocky and sandy biotopes. The name of these aulonocars is given in honor of the English businessman-aquarist Stuart Grant, who settled in Africa, purchased land on the lake from the Government of Malawi and built a station there for the collection, storage and export of Malawian cichlids. In addition to catching fish at the Stuart Grant station, breeding of rare species and forms of cichlids is carried out, as well as scientific research and study of the flora and fauna of the lake. A small hotel on the territory of the station is capable of hosting groups of fanatical aquarists who wish to see all this unique underwater diversity with their own eyes.

Aulonokars are very cautious and shy, hiding between rocks and stones at the slightest carelessness of an underwater observer. They feed on sandy soils looking for small benthic invertebrates. Males ready for spawning are most often found directly in front of rocks or in the first rows of rocks. Spawning takes place in small caves. Then the females, incubating the eggs, hide between the stones. After spawning, females form small groups that are located between the territorial zones of males.

Aulonocara maleri (Aulonocara sp. “Maleri”) among lovers of the whole world has several names - yellow peacock, sunny peacock or orange aulonocara. In addition, this species of fish was assigned to the geographic race of Bensha Aulonocara (A. baenschi). The names speak for themselves and it seems to me that there is no need to describe the coloration in detail.

Fish are common near the islands of Maleri, Chidunga, Namalenji, and others in the southern part of the lake. Males from Maleri Island are small - up to 9.5 cm. "Giants" from Namalenji Island can reach 13 cm, but form a very small natural population. Females are greyish, characteristic for all aulonocara coloring, 2-3 cm smaller than males.

In aquariums, the most common is a small form from the Malery Islands, which is often called by a double name - Maleri Malery's aulonocara. Accordingly, the form from the island of Namalenji will be called the Aulonokara Maleri Namalenji. Inhabiting, like Mbuna, rocky and transitional biotopes, these aulonocara feed mainly on benthic organisms of animal origin. They breed in small caves made of stones, which are guarded by males in bright spawning colors. Local catchers still find these fish, having seen the bright, like sun glare, overflows of spawning males. The pink aulonocara, which appeared in recent years among aquarists as a result of long-term selection work, is very similar to all yellow-pink aulonocara, but the female is almost the same color as the male, but somewhat dimmer.

Aulonocara Maylanda - Aulonocara maylandi Trewavas, 1984- these fish are distinguished by a bright yellow stripe running in mature males in the upper part of the head from the tip of the snout to the base of the dorsal fin. In good males, this bright stripe passes to the dorsal fin.

At present, at least 20 species and color variations of aulonocara are offered to the attention of aquarists, which easily interbreed. For this reason, each species of these fish is recommended to be kept in a separate aquarium, which makes it difficult to create their collections. Fry from different Aulonocara species should also not be mixed in the same pond, as they are very difficult to distinguish. The same applies to adult females.

Haplochromis Borley - Copadichromis borleyi (Iles, 1966)- is generally considered one of the most attractive Malawian cichlids. Originally found near the islands of Likoma and Chizumulu, Borla's haplochromis has several color variations, of which we most often have the red Kadango caught from the so-called Crocodile Rocks. Fish are distinguished by the orange-red coloration of the body of males behind the gill covers. In males outside the period of spawning activity, 3 rounded dark spots on the body are clearly visible, which are located diagonally, starting from the caudal peduncle. The fry are also quite attractive - their orange fins contrast beautifully with their silver body. Males grow to a size of about 15 cm, females are smaller. The coloration of females in many respects resembles the coloration of juveniles. In nature, fish adhere to rocky biotopes at depths of at least 12 - 15 meters. At the same time, the basis of their diet is plankton. Males during the spawning period are very territorial and zealously guard the chosen site somewhere under an overhanging rock. Often they build a kind of nest, clearing the place from sand and organic residues that have settled on stones. There have been cases of spawning in caves. At the same time, the spawning process itself can also occur in the “upside down” position.

Nimbochromis polystigma - Nimbochromis polystigma Regan, 1922- characterized by numerous small spots, which can vary in color from dark brown to brownish-orange, depending on the local race. Moreover, males in breeding plumage become monochromatic and are colored blue-green with a purple tint. In nature, fish grow up to 23 cm in an aquarium, usually somewhat smaller. Males are larger than females. Natural habitats for polystigma include thickets of valisneria, however, during the moments of hunting, they do not limit themselves to anything and, pursuing prey, equally swim on stones and sandy biotopes. Underwater observations also note a method of luring fish juveniles similar to that described below for Livingston's nimbochromis. Fish can hunt both singly and in packs. Pack hunting often occurs in thickets of aquatic plants. At the same time, the flock “combs” its possessions section by section, eating up all the little fish that comes across their path. In an aquarium, polystigmas perfectly eat almost everything that they are not offered. Similar to the previous species, Vallisneria or other plant foods are needed to normalize digestion in their diet. Sometimes, only by transferring obese fish in an aquarium to a strict plant-based diet (90% plant food and 10% animal food) can their ability to reproduce be restored. Usually it takes 1 - 2 months. All this applies to other Malawian cichlids. For Mbuna, the diet can be even more restrictive and include almost 100% vegetable matter.

Cichlid - dormouse or Nimbochromis (formerly haplochromis) Livingston's Nimbochromis livingstoni (Guenther, 1893) is one of the most popular aquarium cichlids due to the attractive coloration of fry and adult fish. The natural diet consists of small fish, which they attract, depicting dead, half-decayed fish lying motionless on the bottom. Curious juveniles that are within reach are instantly grabbed and swallowed by them. Like the previous species, N. livingstoni is a characteristic inhabitant of the lake, the color of which does not allow it to be confused with any other species. Reproduction and maintenance in the aquarium is typical for other members of the group.

Nimbochromis fuscotaeniatus (Regan, 1922) relatively new species in our aquariums. Males in mating coloration are very similar to other types of nimbochromis - polystigma, Livingston, Linni. However, their coloration is more orange-red. In a calm state, the spots and stripes of a characteristic species are clearly visible in the fish, which make it easy to distinguish between pure species that have not been mixed by hybridization. The female nimbochromis fuscoteniatus is easily distinguished from other nimbochromis species due to a continuous longitudinal stripe in the middle of the body. Protomelas phenochilus (Trewavas, 1935) is one of the most beautiful Malawian species. The bright blue basic coloration of adult males is decorated with matte silver spots of the most diverse form. With age, this silver becomes more and more, and the fish become simply irresistible. Females are much more modest in color and, like juveniles, resemble "haplochromis" electra (now Placidochromis electra). Like blue dolphins (Cyrtocara moorii), phenohilus, similar in shape to them, feed on the remains of large letrinops cichlids (Letrinops praeorbitalis) constantly digging sand. Accompanying letrinops everywhere, they manage to pick up edible parts among the dregs raised by these fish. According to observations in the aquarium, neither small nor large phenochilus have "bad" habits and, with good nutrition, do not pay attention to aquatic vegetation.

Placidochromis electra - Placidochromis electra (Burgess, 1979)- also called deep-sea haplochromis, since most fish are easiest to find at depths below 15 meters off the island of Likoma. However, several more local populations have recently been discovered. The fish are mainly found on sandy bottoms and are light blue in color. Under conditions of deep-sea lighting, their coloration is an excellent camouflage. Characteristic of the species is the presence of a clearly visible dark stripe behind the gill covers. There are no other species with similar coloration in Lake Malawi. Males are brighter, larger and grow up to 17 cm in natural conditions. Their diet is based on various small invertebrates and algae. Like blue dolphins, they often accompany large letrinops burrowing in the ground, picking up what they can. When choosing spawning grounds, males are not too picky, so spawning can occur both on sand and on a rocky substrate.

Aristochromis - Aristochromis christyi Trwavas, 1935- one of the largest species of Malawian cichlids presented in our aquariums. Males grow somewhat larger than 30 cm, females are smaller. Only Fossorochromis rostratus reaches the same approximate size. Aristochromis are real predators. At home, they are found in transitional biotopes between rocks and sandy-silty bottom and feed on small fish, often representatives of Mbuna and their juveniles. Observations in the aquarium show that these predators are able to grab and tear fish up to 10 cm in size. The unique outlines of Aristochromis, their characteristic color with an oblique stripe, attract the attention of aquarists despite the habits of obvious predators, constantly busy tracking and stalking prey. Unlike Mbuna, Aristochromis have specific breeding seasons. During these periods, males become completely blue with a greenish tinge. In this case, the band completely disappears. Males in this color are not engaged in hunting, and their main goal is to attract sexually mature females and spawn. Spawning takes place among the rocks. Spawned females usually hide in caves, where they subsequently release juveniles. Care for the fry continues by the female for about a month. Due to their large size, the reproduction of Aristochromis in the aquarium has not yet been sufficiently mastered. Species close to them in appearance and hunting manner belong to the genera Exochochromis and Champsochromis, which are extremely rare among aquarists. Appeared under the name "Red-Top Aristochromis" cichlids, in fact, belong to the genus Otopharynx.

Protomelas taeniolatus - Protomelas taeniolatus (Trewavas, 1935)- belongs to the Utaka group - haplochromids feeding on plankton in open waters. Most often, these fish are caught in shallow water. Males grow up to 16 cm, females are smaller. The coloration of the sexes is very different; females, like juveniles, are silvery with a longitudinal dark stripe, while males are distinguished by bright, multicolored coloration with numerous blue-green spangles on a cherry background of the body. In addition to size, males look more powerful. Judging by the fact that the fry of these fish are found in the lake at the end of November, they have a more or less pronounced seasonal pattern of reproduction (at the end of autumn). Spawning takes place on a sandy substrate, where the males dig out a kind of nest. In the conditions of the aquarium, no seasonality was noted. It is also variable and occurs near the rocky biotopes of the lake at depths of no more than 10 meters.

This one was first introduced by the author in the seventies under the name boadzulu. In those days, under this name, several haplochromid species, which vary greatly in color, were exported - H. steveni, H. fenestratus, H. hinderi, etc. The real boadzulu, judging by the available information, did not get into the aquariums of cichlid lovers. Local residents everywhere catch representatives of the Utaka group and eat them, after drying them in the hot African sun.

Cornflower blue haplochromis - Sciaenochromis ahli (Trewavas, 1935) known to us as haplochromis Jackson. Males of surprisingly bright cornflower blue color reach 20 cm in length and feed on fry of other Malawian cichlids, as well as juvenile catfish hiding between rocks. Females are smaller and, like fry, show protective coloration. Except during the breeding season, the fish are not territorial and therefore many brightly colored males can be kept in the same aquarium together with other species of utaka and some mbuna (see photo on page 2 of the cover). Males of northern populations have more yellow-orange pigment, especially in the coloration of the anal fin. Surprising for the living world, the brightness of the blue color is retained by adult males throughout their lives, noticeably intensifying at moments of irritation, aggression and spawning activity. Like other Malawians spawning without any pronounced seasonality, females incubate eggs in their mouths for three weeks.

Cornflower blue "haplochromis" was assigned to the genus Sciaenochromis (Sciaenochromis), in which it is to this day. However, in addition to the name Sciaenochromis ahli, fish exclusively similar to the cornflower "haplochromis" began to be called S. fryeri. This is how long the chain of renaming turned out to be. The natural diet of cornflower blue "haplochromis" consists mainly of mbuna fry, which are found between stones all year round, and also in the winter months, despite the vigilant protection of producers, they manage to "steal" fry from the nests of flathead catfish Bagrus meridionalis. The spawning season for these catfish, called "campango" by the locals, usually lasts from November to February.

Cichlid - knife or compressiceps - Dimidiochromis compressiceps (Boulenger, 1908) one of the unusual in shape and most interesting in behavior small predator. In early writings on ichthyology, these fish were described as the most unique representatives of Lake Malawi, specializing in feeding on the eyes of other cichlid species. In fact, everything is not so scary - German hobbyists considered these small fish hunters to be the ideal fish for guppy breeders. Feeding compressiceps with substandard fish culled by the breeder guarantees the normal development of the knife cichlid. Hunting for fry is very peculiar - while the fish swim head down. Reproduction of compressiceps occurs, as in other Malawian cichlids. Among the genus Dimidiochromis, one more species is found in our aquariums - Dimidiochromis strigatus (Regan, 1922). The red form of compressiceps is known, but so far very rare in our country.

Consists of living organisms, the habitats they live in, non-living structures, and how they all interact and influence each other. Marine ecosystems are found in or close to salt water, which means they can be found from the sandy beach to the deepest regions of the world's oceans. An example of a marine ecosystem is a coral reef with its inhabitants (fish, sea turtles, algae, etc.), as well as water, stones and sand in the area.

Ecosystems can vary in size, but all of their components are dependent on each other - so if one part of the ecosystem is removed, it affects all the others.

The ocean covers 71% of the planet, so marine ecosystems make up the majority of the Earth. This article provides an overview of the main types of marine ecosystems, with examples of the habitats and marine organisms found in each.

Rocky coast ecosystem

Along the rocky shore, you can find rocks, small and large boulders, stones, as well as tidal pools, which are capable of supporting incredible diversity. There are also intertidal zones - areas of the coast that are flooded with sea water during high tides.

Rocky shores are extreme habitats for marine life. They are characterized by powerful waves, high winds, and constant tides that can affect water availability, temperature, and salinity. At low tide, the threat of predation to marine animals increases significantly.

Sea life of the rocky shore

The specific types of marine life vary by geographic location, but in general, some types of flora and fauna found on the rocky shore include:

• Seaweed;
• Lichens;
• birds;
• Invertebrates such as crabs, lobsters, starfish, hedgehogs, mussels, snails, sea limpets, ascidians and sea anemones;
• Seals and sea lions.

Ecosystem of sandy beaches

Sandy beaches can seem lifeless compared to other ecosystems in the seas and oceans - at least to marine life. Most of the sandy beaches are exposed to human impact! However, they have an amazing variety.

Animal ecosystems on a sandy beach, like those on a rocky shore, must adapt to an ever-changing environment. They need to deal with tides, wave action, water currents that can sweep animals off the beach and move sand and rocks.

The marine life of a sandy beach may burrow into the sand or move quickly away from the waves. Intertidal zones are not uncommon within this ecosystem. Although the scenery is not as dramatic as on the rocky shore, tide pools can still be found left behind after the ocean recedes at low tide.

Marine life sandy beaches

Occasionally, on sandy beaches, sea turtles can be seen emerging from the water to lay their eggs, as well as pinnipeds such as seals and sea lions resting on the beach.

Typical types of marine life include:

• Seaweed;
• Plankton;
• , such as amphipods, isopods, flat shield urchins, crabs, mollusks, worms, snails, flies and plankton;
• Fish, in shallow water along the beach line. These include skates, sharks, flounder, etc.;
• Birds such as plovers, gerbils, hymentoed snails, godwit, herons, terns, turntables and curlews.

Mangrove ecosystem

Areas consisting of salt-tolerant plant species. They tend to be located in warmer areas between 32°N and 38°S. Mangrove trees have roots that hang down into the water, providing hiding places for a variety of inhabitants, and an important refuge for young marine animals.

marine life mangroves

Species that can be found in mangrove ecosystems include:

• Seaweed;
• birds;
• Invertebrates such as crabs, shrimp, oysters, snails and insects;
• Dolphins;
• Manatees;
• Reptiles such as sea and tortoises, alligators, crocodiles, caimans, snakes and lizards.

Salt marsh ecosystem

Salt marshes provide a buffer between the ocean and the mainland. These areas are flooded at low tide and contain salt-tolerant animals and plants.

Salt marshes are important in many ways: they provide habitat for marine life, migratory birds, are important nurseries for fish and various invertebrates, and protect the rest of the coast by buffering wave action and absorbing water during high tides and storms.

Marine life of salt marshes

Examples of salt marsh flora and fauna include:

• Seaweed;
• Plankton;
• birds;
• Sometimes marine mammals such as dolphins and seals.

coral reef ecosystem

Healthy coral reef ecosystems are filled with an amazing variety of life, from hard and soft corals to invertebrates of various sizes, and large animals such as sharks and dolphins.

The main part of the reef is the coral skeleton, which is composed of limestone (calcium carbonate). It supports tiny organisms called polyps. When the polyps die, they leave the skeleton behind.

marine life coral reef

• Invertebrates: hundreds of species of corals, sponges, crabs, shrimp, lobsters, anemones, worms, bryozoans, starfish, urchins, nudibranchs, octopus, squid and snails;
• : a wide variety of fish, as well as sea turtles and marine mammals such as seals and dolphins.

seaweed forest

The algae forest is a fairly productive ecological system. The dominant life form in this underwater forest is, you guessed it, algae. They are found in cooler waters ranging from 5 to 22°C at depths of 2 to 30 meters. This ecosystem provides food and shelter for a range of organisms.

Sea life in the seaweed forest

• Seaweed;
• Birds (gulls, terns, waders, cormorants, etc.);
• Invertebrates such as crabs, starfish, worms, anemones, snails and jellyfish;
• Fish, including sardines, garibaldi, perch, seabass, barracuda, halibut, mackerel and sharks (eg horn shark and leopard shark);
• Mammals such as sea otters, sea lions, seals and whales.

polar marine ecosystem

Polar ecosystems are extremely cold oceanic waters at the Earth's poles. These areas are characterized by both low temperatures and temperature fluctuations depending on the amount of sunlight.

Marine life in polar ecosystems

• Seaweed;
• Plankton;
• Invertebrates: One of the most important invertebrates of the polar waters is the krill;
• Birds such as penguins are known for their cold hardiness, but they are found only in the Southern Hemisphere;
• Mammals such as polar bears, various types of whales, as well as seals, sea lions and walruses.

deep sea ecosystem

The term "deep sea" refers to parts of the ocean that are more than 1,000 meters deep. But compared to some areas of the ocean, this is shallow water, since the deepest areas reach about 11,000 meters in depth.

Lack of light is one of the main problems for marine life in this ecosystem, but many animals have adapted to see in low light conditions, or no need to see at all. Another problem is pressure. Many deep-sea dwellers have soft bodies, so they can easily endure high water pressure.

deep sea life

The depths of the ocean are difficult to explore, which is why we are still learning about the types of marine life found there. Here are some examples of the inhabitants of the deep sea:

• Invertebrates such as crabs, worms, jellyfish, squid and octopuses;
• corals;
• Fish such as anglerfish and some types of sharks;
• Mammals: sperm whales and elephant seals.

hydrothermal vents

Although typically found in the deep reaches of the ocean, hydrothermal vents serve as their own ecosystem.

These holes are underwater geysers that spew mineral-rich, very hot water into the ocean. Hydrothermal vents are located along tectonic plates where there are cracks in the earth's crust. Sea water in cracks is heated by terrestrial magma. Under pressure, water erupts and cools, and minerals are deposited around the vents.

Doesn't sound like a very cozy place to live, does it? Despite the darkness, heat, water pressure, and chemicals that are toxic to most other marine creatures, some organisms thrive in hydrothermal ecosystems.

Marine life at hydrothermal vents

• - microorganisms that carry out chemosynthesis, which means the conversion of chemicals around hydrothermal vents into energy. They are the backbone of the hydrothermal ecosystem;
• Invertebrates such as rifts, limpets, clams, mussels, crabs, shrimp, lobsters and octopuses;
• Fish such as eelpouts;
• Colorful coral reef near the Similan Islands, Thailand.