Schooling zebrafish in your aquarium, how to care for and breed? Danio pink (Danio roseus) Danio disease and treatment
In the aquariums of European zebrafish lovers, pink appeared in 1911. Since then, he has become their permanent resident. This is due to the unpretentiousness, peaceful and playful disposition of the fish and its good breeding ability. Danios are usually kept in a common aquarium. Even a novice can handle it.
Description
The pink zebrafish belongs to big family cyprinids. It has an elongated and, as it were, flattened body from the sides, two pairs of antennae located at the edges of the mouth, shiny scales on the back and sides, having a complex combination of colors: olive, blue, green, gray.
The belly is colored pink. In sexually mature males, it acquires a rich bright pink hue. Young fish from the sides have red wedge-shaped stripes that run from the tail to the middle of the body, transparent fins with a greenish tint and a small cherry or red anal fin.
An adult pink zebrafish grows up to five centimeters in length. AT vivo you can find specimens up to eight centimeters.
In nature, this fish is widespread - from India to the countries of Indochina. There, large flocks of zebrafish live in the water of small streams and rivers.
Danio pink - how to distinguish a female from a male
Be able to identify gender aquarium fish ok important, especially if you want to breed them and get offspring in as soon as possible. Undoubtedly, you can experiment and gradually put several fish into a separate “house” and wait for the females to start spawning. In fact, there are signs by which an experienced aquarist determines the sex of the fish.
Female
It’s good if the beginner managed to notice how the fish spawns, and he was able to mark it in some way. Then this individual can simply be placed in the spawning ground. It is more difficult when this is only the first offspring, or the female must be selected from the “herd” upon purchase.
The easiest way in this case is to focus on the size that the zebrafish has pink. The female (adult) is larger than the male, it has a rounded belly, while the male is smaller in length and much thinner. According to this principle, you can only choose adult fish of the same age, since the first few months the male zebrafish can be larger than the representatives of this species.
Male
A method proven by many aquarists to find a male among fish is coloring. Pink zebrafish(male) has stripes on the body much brighter than the female. This is very important during the “mating season”, when the female chooses the largest and brightest partner for herself before spawning. It is always the leader in the pack. Some aquarists distinguish the sex of the fish by the shape of the anal fin - in females it is slightly rounder and larger. But this is an unreliable criterion for selection, in this case it is easy to make a mistake - in fish it has almost the same size. Try to watch the fish during the mating season. Males always develop very great speed, circling around their "ladies of the heart." Therefore, inside such a circle is a female, and a fish rushing around her is a male.
For many beginner aquarists, the first fish is the pink zebrafish. Its content is not too difficult, a beginner can easily handle it. You will need a rectangular aquarium with a volume of at least 50 liters and a height of about thirty centimeters. It should be covered with glass or a lid, as these fish are not only swimmers, but also excellent jumpers.
You can use fine granite chips, clean and coarse river sand, pebbles as a soil. Plant small-leaved plants along the back and side walls. At the front glass, the space remains open.
Water parameters
It should be noted that the pink zebrafish is not too picky about the composition of water (chemical). For this species, it is not too important how many salts are contained in the water. A hardness not exceeding 20°dH is suitable for it. pH - 6-7.5. Comfortable water temperature +18 - +22°С.
The aquarium must be provided with filtration and artificial aeration of water. Once a week, you should change a fifth of the water to settled fresh.
Lighting
Danio pink loves bright lighting. For this purpose, it is more expedient to use LB fluorescent lamps. They are best placed along the front glass. Danio pink will only benefit if oblique incident rays illuminate it. It is desirable that natural sunlight enters the aquarium for two hours a day.
Compatibility
Danio pink, as well as other members of its genus, is a peace-loving fish. She gets along well with other species that need the same conditions of detention, and at the same time is not very cocky.
Feeding
I must say that this small fish has an excellent appetite. She eats all types of dry and live food of the appropriate size. You can feed danios with coretra, bloodworms, daphnia, young brine shrimp. They also pick up small insects from the surface of the water.
Danio pink - breeding
Two males go to spawn for one female. Sometimes several individuals are deposited in the same ratio. The fact is that female zebrafish, like other species of the genus, often have cysts. Because of this, the female may be infertile. And one more subtlety - decanting caviar from fish small breeds quite problematic, so females up to a year old are selected for spawning. Choosing males is much easier.
Two weeks before the start of spawning, females must be separated from males and kept separately. During this period, they are intensively fed with live food. During this time, the female's abdomen will noticeably round, which indicates readiness for spawning.
We prepare the spawning ground
It should be at least ten liters per female. We lay a separator mesh at the bottom. It covers the entire bottom and is located at a height of about two centimeters from it. Instead of a net, many aquarists use small-leaved plants that are pressed to the bottom with pebbles. It is important to properly prepare the water. It must be fresh and settled. One third of it should be boiled water. This will allow you to get optimal hardness - no more than 10°dH. pH = 7.
The water temperature when transplanting fish into the spawning ground should be the same as in the aquarium where they were previously kept. Water should cover the separator mesh no more than 5 - 8 centimeters.
In the evening, males are sent to the spawning ground, and after a few hours, females. Set the temperature on the thermostat to 26-28°C. And then the lights are turned off in the spawning ground. The next morning, at dawn or when artificial lighting is turned on, spawning begins.
It continues for several hours. During this time, the female spawns more than two hundred eggs, painted in a soft milky color. After that, the parents should be removed from the spawning grounds. In addition, you can remove the separator mesh by carefully but carefully brushing off the eggs from it.
Incubation continues for two days. After about four days, the fry will already be able to swim, and they will be able to get their first "lunch" - ciliates, Artemia nauplii, live dust. Over time, they are transferred to larger foods and moved to a larger aquarium. At six to eight months, the danio pink reaches puberty. Reproduction of these fish is not difficult, but it will require accuracy from a beginner.
Diseases
Danio is loved by almost all beginner aquarists. This is an unpretentious, beautiful fish that does not create problems in the growing process. But, unfortunately, like other inhabitants of the aquarium, she can get sick, and her owner must be able to distinguish the symptoms of the disease and treat his pet.
Bloating
Zebrafish diseases have various symptoms. In this case, the abdomen increases by 2 times. Beginning aquarists confuse this phenomenon with overeating or the presence of eggs, but in most cases this is a sign of a disease. Danios are prone to it, and owners often face this problem.
Danio lies at the bottom, almost does not swim. For treatment, use "Metronidazole" (1 tablet per 30 liters of water). After 7 days, the disease should go away. Such treatment will be useful for other inhabitants of the aquarium, as a prophylactic.
growths
They appear on zebrafish pink extremely rarely. But if this happens, it is necessary to increase the level of salt in the water and the temperature. The fish should be placed in liter jar and add 2 tablespoons of salt (tablespoons). Hold it in this solution for 15 minutes (water temperature +28 degrees), then transplant into a common aquarium. The growths will come down in two days.
Swimming in circles
Sometimes you can notice that the zebrafish begins to swim in a circle, but at the same time remains quite active, reacting to its neighbors in the aquarium. Most often this happens when poisoning. Some specimens are too sensitive to nitrates, so you need to change the water, and change 1/3 of the aquarium water every three days.
bulging eyes
This disease is typical for adult fish. It happens during spawning. The body does not change its color, but the abdomen is significantly enlarged, which at first glance seems natural during spawning. But then, for fifteen days, the eyes of the fish protrude from their sockets, and then fall out. A blinded fish dies of exhaustion. A white thick mass is found at autopsy behind the eyeball, which causes bulging eyes. Poor quality water is the cause of this disease. Treatment: water change (partial) - every 2 days.
Trichodinosis
The causative agent of this disease can be Trichodina ciliates. It has spike-like processes. With their help, it is attached to the fish. This mainly occurs on the gills and skin of zebrafish. It enters the aquarium along with soil, plants, food, if they have not been properly disinfected.
Symptoms of the disease: the fish rubs against hard plants and objects, more often than usual swims up to aeration. With the development of the disease, the body color fades, a grayish-white coating can be seen on the skin. It separates into large flakes.
Treatment of trichodinosis: it is necessary to increase aeration, increase the water temperature to 31 degrees. Such therapeutic baths should be done in a separate aquarium with the addition of table salt or tripaflavin.
To prevent diseases of zebrafish pink, simple rules should be followed. All items that are placed in the aquarium must be thoroughly disinfected in manganese or boiling water.
Size of hydrobionts - M L
Add to cart Remove from cart
Fish size
M - up to 3 cm, XL - up to 4 cm.
Habitat
The main habitat of these fish are quiet rivers Thailand and about. Sumatra.
Description
The length of this species of zebrafish is up to 6 cm. The body is elongated, slender, moderately flattened laterally. 2 pairs of antennae. The back is gray-olive, the side is gray-green, silvery and, depending on the lighting, casts greenish, bluish or purple. Along the body, starting at the level pectoral fins and gradually expanding towards the caudal peduncle, there is a red stripe with a blue border, which becomes weaker with age and may disappear altogether. Dorsal yellowish green, anal fin cherry to orange red, tail greenish. Fish are especially beautifully colored when kept in a large flock.
The male is more intensely colored; there may be a cherry-red spot in the middle of the tail. The female is much fuller, especially before spawning.
All zebrafish are exceptionally strong fish with excellent health, so even completely inexperienced lovers succeed in keeping them.
Small pebbles or gravel are perfect as soil. Plants can be planted at your discretion, only the main thing is to leave an open, well-lit section of the aquarium for a flock of zebrafish to swim.
Optimal water parameters for keeping zebrafish: Temperature (t) 20-25°C (summer), 17-21°C (winter). Water hardness (dH) 5-15°. The recommended stiffness is not more than 10°. Acidity (pH) 6.0-7.5.
For the well-being of the fish, it is necessary to change the water every 7-14 days up to 20-25% of the volume of the aquarium, as well as good filtration with aeration. It is good when the temperature of the replacement water is 2-3 degrees higher than the aquarium water, and it is infused.
Breeding
Achieving spawning in zebrafish is very simple. Failures are mainly due to the shortcomings of the conditions of detention. One of these shortcomings can be called too heat water in the aquarium winter period.
Before spawning, males and females should be seated and, after raising the temperature to 23-25 ° C, feed them well with bloodworms or tubules for several days (the latter are worse).
A three-liter glass jar is the most excellent spawning ground for small species. For large species, a cylindrical jar with a diameter of 40 centimeters is most suitable. In these vessels, the bottom is convex in the middle, which is very important. But in extreme cases, you can use a rectangular jar or aquarium with a bottom size of 40 × 20 centimeters for large species.
An excellent plant substrate for spawning is spawning or moss, which amateurs call fontinalyss (Amblystegium riparium). In extreme cases, you can use peristolistol. Plants are laid on the bottom, and pressed with well-washed pebbles. Spawning is poured with tap water, previously settled in a glass or enamel bowl for 6-8 days. You can take water from a clean, safe in all respects aquarium, but in this case it must be properly aerated by strong blowing or repeated pouring from vessel to vessel. The water level in the spawning ground for small species should be 6-9 cm, for large ones - 10-15.
Experiments have shown that the fertility of eggs increases sharply when not a pair, but three adult zebrafish (one female with a rounded abdomen and two males) are used for spawning. The foregoing does not apply to zebrafish. Producers are planted in the spawning area in the evening, and the next day spawning is usually observed, starting the earlier, the brighter the spawning area is lit. If spawning does not follow, the fish should be left in the spawning area for another day, if even then they do not spawn, they are caught, and the eggs are gently squeezed out of the female, squeezed into a wet cotton wool. The operation is easy. The fleece with the female is clamped between the thumb and forefinger of the left hand, the abdomen up. Caviar is squeezed out with light movements of the index finger of the right hand, directed from the head to the tail of the female. After such an operation, the female is ready for spawning in a week.
Chasing the female, the males now and then squeeze out (or rather knock out) eggs from her. And this is where the advantage of a spawning tank with a convex bottom becomes indisputable. The eggs of the zebrafish are non-sticky and, falling to the bottom, they roll along it to the edge of the vessel, under the plants. As a result, they are all preserved. otherwise, all open caviar would have been eaten.
When spawning is over, the fish need to be planted, and it is useful to start blowing the spawning tank.
The temperature during zebrafish spawning can be from 22 to 28°C.
The larvae hatch in 3-4 days. On day 6-7 they need to be fed with ciliates.
Further, two days later, it is useful to pour the larvae into a jar large sizes and another week to feed infusoria or dust. When the larvae grow up, they should be given cyclops. Soon they will be colored, turning into fry.
Feeding
Danios are undemanding to feed. However, preference should be given to live ones over dry and artificial ones, and bloodworms, coretra and small soft daphnia are the best for living zebrafish. Feeding two or three small portions a day is better than feeding once, especially during the breeding season. With a single feeding, it is preferable to do this in the morning. Danio takes food from the surface of the water, but can also sink to the bottom for food.
Instructions for use
Important! In winter, if you do not set goals to get offspring at this time of the year, zebrafish should be kept at lower temperatures than in summer.
DISEASES OF DANIO
Buying a zebrafish Special attention pay attention to integrity skin and fins. At the same time, the fading of the color does not always indicate illness, just moving - transplanting during the sale process could cause a shock. But even if the zebrafish looks healthy, it must be kept in a separate aquarium in quarantine for a couple of weeks.
The zebrafish is very disease resistant. Despite the fact that she rarely gets sick, you need to have aeration in the aquarium. For the correct maintenance and prevention of diseases in zebrafish, a clean water regime is very important. When feeding her, one must adhere to the rule - it is better to underfeed than to overfeed. It is overfeeding that is usually the cause of zebrafish illness.
Most often, danios suffer from bulging eyes. The disease usually strikes them at the age of several years during spawning. The color of the body does not change, but the abdomen noticeably increases, which looks natural during the spawning period. For two weeks, both eyes protrude more and more from their sockets, then one by one they fall out. Blind fish die from exhaustion. At autopsy, a thick white mass is found behind the eyeball, which causes bulging eyes. The reason is poor quality water. Treatment: partial water change every 2 days.
Another disease that zebrafish suffers from is trichodinosis. The causative agent is the ciliate Trichodina, which has spike-like processes with which it is attached to fish. Localized on gill filaments and skin. Enters the aquarium along with plants, soil and food if they have not been properly disinfected.
Signs of illness: the fish begins to rub against hard objects and plants, more often than usual swims up to aeration bubbles. As the disease progresses, the color of the fish fades, a grayish-white coating is visible on the skin, which is separated by flakes. Treatment of trichodinosis: increased aeration, raising the water temperature to 31 degrees. Therapeutic baths are made in a separate or shared aquarium with table salt or tripaflavin.
Danios are prone to obesity.
Prevention of zebrafish diseases
To prevent zebrafish diseases, you must follow simple rules. All items brought into the aquarium must be disinfected: in a manganese solution, in boiling water or with other disinfectants.
Danio is the favorite fish of almost every novice aquarist. She is beautiful, unpretentious, very friendly and does not create any problems in the process of growing. But, like other inhabitants of the aquarium, she can get sick and who, if not her owner, should study her “tricks” and know how to cure a pet? Consider the main diseases and ways to deal with them in order to meet the problem with all weapons!
The main diseases of zebrafish pink
Bloating. The first signs of the disease are an increase in the belly by 2 times. Some aquarists confuse this with overeating or caviar, but in most cases it is bloating. Zebrafish are prone to it and very often their owners are faced with such a problem. Danio lies on the bottom, practically does not swim, does not contact with fish, and the stomach is much larger.
It is necessary to treat with metronidazole (1 tablet per 30 liters of water). In a week the disease should pass. For prevention, you can “drink” other residents in the aquarium - there is nothing wrong with that.
Swimming in circles. In some cases, the fish begin to swim in a circle, but remain quite active and react to other participants in the "movement". As a rule, this behavior occurs when poisoning. Some individuals are very sensitive to the amount of nitrates, so you just need to replace the water with normal composition and periodically (1 time in 3 days) change 1/3 of the aquarium water.
growths. There are practically no such growths on zebrafish, but if such a disease occurs, then you just need to increase the salinity of the water and the temperature. Separate the fish into a jar and add 2 tablespoons of salt. Keep it there for 15 minutes at +28 degrees, then put it back in the general aquarium. The fluffy growths will die and disappear in a couple of days.
Danio - fish that appeared in my aquarium thanks to dad. This is after I swapped my gouramis for neon ones. Out of a dozen danios of two species (striped and pink), 5 pieces are now left. We need to think about buying more or just try to breed these funny fish. But that's in the future. I decided on this page to collect the most full information about aquarium zebrafish, along with my photos and not my videos
By the way, zebrafish are quite agile fish and it was extremely difficult to photograph them. In general, I would not really like to have such fish rushing around the aquarium in my relaxing pond. But my father decided otherwise.
Danio (lat. Danio) is a genus of small ray-finned fish of the carp family, some species are common in the aquarium hobby. They inhabit reservoirs with stagnant and running water in Southeast Asia. The most popular in the aquarium hobby is the zebrafish.
The zebrafish is a model organism in developmental biology and is known in the English language literature as the zebrafish. Zebrafish is the first pet genetically modified with bioluminescence genes in 2003 (GloFish)
GloFish is a proprietary commercial brand of GloFish that sells genetically modified fluorescent fish; originally they were zebrafish (lat. Danio rerio) - a type of unpretentious and popular aquarium fish of the carp family. Genetically bred GloFish individuals are distinguished from their original form by a red, green or orange fluorescent coloration that becomes more visible and intense under ultraviolet light. Although not originally bred as ornamental fish, they became the first genetically modified pets available to the public.
Transgenic zebrafish differ from their original form in body color. DNA fragments of jellyfish (lat. Aequorea Victoria) and red coral (from the genus lat. Discosoma) are built into their DNA. Zebrafish with a fragment of jellyfish DNA (GFP gene) have green color, with coral DNA (RFP gene) is red, and fish with both fragments in the genotype are yellow. Thanks to the presence of these foreign proteins, the fish glow brightly in ultraviolet light.
The transgenic form prefers more warm water- about 28 °C. Maintenance, feeding or differences in breeding and development of genetically modified Danio Rerio have not been noticed: transgenic fish are also unpretentious in maintenance and peaceful.
History of GloFish
The natural zebrafish from which GloFish was grown lives in the rivers of India and Bangladesh. It has a size of about three centimeters in length and gold and blue stripes located along the body. Over the past 50 years, these fish have been sold in the US ornamental fish market for over $200 million, but despite this, no one has been involved in their reproduction in the US, primarily because they are tropical fish and cannot exist in temperate North American climate.
In 1999, Dr. Zhiyuan Gong and his colleagues at the National University of Singapore worked on the green fluorescent protein (GFP) gene, which nature has endowed only in some Pacific jellyfish. This gene is responsible for the synthesis of a phosphor protein, which emits rays of a pleasant greenish color in the dark. They inserted this gene into a zebrafish embryo, creating a genome that gave the fish natural-like bright fluorescent colors. white light and from ultraviolet radiation.
The original goal of genetic engineers was to make it easier to observe the internal organs of these translucent fish. But the photograph of a fish glowing with a greenish ghostly light, shown in scientific conference, saw a representative of a company engaged in the breeding and sale of aquarium fish. By order of the company, the zebrafish genome was supplemented with a red glow gene isolated from sea coral. The resulting breed was named "Night Pearl".
In the United States, luminous zebrafish were originally obtained in order to create living indicators of pollution: in the presence of certain toxic substances in the water, the fish had to change color. But in 2003, businessmen and scientists entered into a contract, according to which the first genetically modified GloFish fish appeared on the market.
In addition to the red fluorescent zebrafish sold under the brand name Starfire Red, green and orange-yellow fluorescent zebrafish were introduced by mid-2006, followed by blue and purple zebrafish in 2011. These fish lines have been traded under the trade names Electric Green, Sunburst Orange, Cosmic Blue, and Galactic Purple. .Galactic Purple). All of these fish have been genetically engineered using recombinant DNA from various marine corals.
In 2012 appears new variety fluorescent aquarium fish under the brand name of the green variety of the English. "Electric Green" GloFish, which were bred by the same method as the previous ones, but instead of zebrafish, ordinary thorns (lat. Gymnocorymbus ternetzi) were used. In 2015, luminous green Sumatran barbs (lat. (Puntius tetrazona)) were introduced.
Despite the widespread opinion about the sterility or sterilization of genetically modified fish in order not to spread them in natural water bodies, it is possible to get completely healthy and viable offspring from GloFish. and the sale of GloFish fluorescent fish is strictly prohibited.
The sale and possession of GloFish remains illegal in California due to an ordinance restricting the farming of any genetically modified fish. The regulation was introduced prior to GloFish sales, mainly due to concerns about the biotechnology of fast-growing salmon. Although the fish commission refused to grant an exemption (on ethical grounds) in December 2003, it subsequently reversed course and decided to move forward with the goal of deregulating GloFish.
Canada also bans the import and sale of GloFish due to lack of sufficient information to make a safety decision.
Within European Union import, sale and storage of these fish is not allowed. However, on November 9, 2006, the Ministry of Housing, Spatial Planning and environment The Netherlands found 1400 fluorescent fish, which are sold in various stores from aquariums
But back to the zebrafish. Danio rerio is a model organism that is used to study vertebrate development and gene function in vertebrates. Early work by George Streisinger at the University of Oregon showed the potential for using Danio rerio as a model organism; the importance of this model has been confirmed by many genetic studies. Danio rerio is one of the few fish species that have been on an orbiting space station.
As a subject of developmental biology, Danio rerio has some advantages over other vertebrates. The embryo develops quickly, going from egg to larva in just three days. Embryos are large, hardy, strong, transparent and develop outside the mother, which facilitates manipulation and observation.
Antisense Morpholino technology is often used to turn off genes or change splicing in Danio rerio. Such oligonucleotides are synthetic macromolecules containing DNA or RNA nucleotides that bind to complementary RNA sequences and reduce gene activity. Morpholino oligonucleotides can be introduced into embryonic cells after the 32 cell stage, resulting in an organism in which gene activity is reduced only in those cells derived from the modified cell. Although cells of the early embryo (less than 32 cells) are impermeable to large molecules, they allow Morpholino molecules to penetrate between cells.
On January 23, 2013, Spanish scientists conducted an experiment to introduce the hoxd13 gene, borrowed from four-legged mice, into the fish genotype. Fish have a similar gene, but do not show sufficient activity. As a result of the experiment, the fish received the rudiments of limbs suitable for movement on land.
Danio species from kwitri.ru
The most common species in modern aquariums remains zebrafish, or zebrafish. As in other species, the female has a more rounded abdomen. Often there are veil forms. The body length of the fish is up to 7 cm.
They are very similar in color and size. The main difference is the orange stripe that runs from the middle of the body to the tail fin of the pearl zebrafish. The body length of the fish is up to 6 cm. This species looks more advantageous with the right lighting. The fish reach sexual maturity at eight months.
Leopard zebrafish got its name for the corresponding color - there are many irregularly shaped dark-colored spots on the body. The body size of the fish is up to 5 cm.
Danio orangefin- got its name because of the color of the fins, their edges are painted yellow-orange. In mature males, the coloration is more pronounced. The body length of the fish is up to 5 cm.
Danio firefly, or danio chopra - a small (up to 3 cm in length), bright fish, painted in orange-yellow tones. The caudal fin appears to be bifurcated due to yellow-colored outer rays, while the central part remains transparent. Along the crest of the back from the head to the dorsal fin there is a luminous strip, and in females it is yellowish, in males it is reddish. In mature females, a bright orange stripe runs along the body.
Danio dangila, or olive - a rather large representative of the family, its body length is up to 10 cm. The body is covered with a peculiar ornament, a distinctive feature is a large dark spot behind the gill cover. This species is undesirable to keep with fish that have veil fins, since in a flock these danios can peel off these very fins. In general, this species (when kept in a flock) is quite aggressive; zebrafish can attack larger fish.
Danio erythromicron, or ribbon microassembly, emerald - a small fish (2.5 cm) of a very original color. Distinctive feature this danio has no whiskers. Peaceful, shy fish, so vegetation in which they could hide is very desirable in an aquarium.
Danio Burmese, or fagradei - fish with a delicate color: golden specks are scattered over the blue body. Behind the gill cover is an orange spot. Males have an orange stripe on their anal and pelvic fins, while females have a white stripe.
Danio blue, or kerry - a fish with a catchy color: two sparkling pink stripes run along the olive-blue body. The male is smaller, slimmer and brighter, the color of females is dominated by gray tones. The body length of these fish is up to 5 cm. The view is peaceful.
Danio Malabar- the largest representative of the genus. The body length of the fish in the aquarium is about 10 cm. The color is very interesting: along the body, slightly receding from the head, 3-4 shiny, longitudinal bluish-turquoise stripes stretch, separated by golden stripes. Immediately behind the gill cover there are several transverse golden strokes and specks of the same color are scattered throughout the body of the fish. In the male, the middle longitudinal blue stripe continues in the middle of the caudal fin, while in the female it passes to the upper lobe. The view is peaceful. These zebrafish reach sexual maturity by one year.
Danio fluorescent, or Danio GloFish - p The fish, according to the conditions of detention, is no different from the original species - zebrafish - unpretentious, schooling and mobile for the upper layers of water in the aquarium.
Danio Bengal- a peaceful, unpretentious, schooling fish with a body size of 7-8 cm. At the level of the dorsal fin, 3 blue longitudinal stripes begin on the side of the body, separated by lines yellow color, which on the caudal fin merge into one strip, passing to its upper lobe. Of all the zebrafish, this species has the longest dorsal fin. Males, like other species, are more graceful and brightly colored.
Danio point- the color of the upper body resembles zebrafish: the same dark stripes on a light background. The lower part of the body and the anal fin are not covered with stripes, but with dark dots. There are also dark stripes on the caudal fin. The length of the fish is not more than 4 cm. The male is smaller than the female, his abdomen is white, the female's is orange. The view is peaceful. For this species, the water temperature should not be lower than 24 ⁰С.
Danio margaritatus, or microsorted galaxy - the brightest representative of zebrafish. My bright color these fish begin to acquire at the age of two months, and by six months they are completely colored. These fish are very beautiful, but their extreme fearfulness prevents them from admiring enough. An aquarium with them must be planted with plants so that the galaxies feel calmer. These fish are kept in large flocks of 20 or more individuals. The water temperature for them should be no higher than 26⁰С, preferably 22-24⁰С.
Since in the event of danger approaching, these fish can jump out of the water into the air so that the pet is not lost, the aquarium should always be covered with a lid. The optimal distance from the water to the lid is approximately 3-4 cm, so that when jumping out, the fish does not hit a hard surface and does not get hurt.
Keeping zebrafish and caring for them at home is quite simple. Fish mainly swim in the upper layers of the water, where oxygen is the most. In this regard, you do not need to install additional aeration of the aquarium.
Danio rerio live in groups. Therefore, if you decide to purchase them, buy 8-10 individuals at once. Since the size of these fish is small - about 4 - 5 cm, an aquarium with a volume of 6 to 7.5 liters is quite suitable for their comfortable living. Optimum temperature water for zebrafish should be about 24 ° C. Although these fish will react quite calmly to its slight changes.
If you want to breed zebrafish yourself, then you need to prepare another aquarium - a spawning tank. The water thickness in it should be no more than 6-8 cm. After spawning, the female and male are seated in different aquariums, after which, after 7 days, the female is again launched for re-spawning in order to avoid her infertility.
Feeding zebrafish is also an important process. For this, dry or live food suitable for this species is suitable. It is very important that the food is crushed, otherwise the fish will not be able to swallow large pieces.
Zebrafish compatibility with other fish
If you have replenished your home living area with these beautiful aquatic inhabitants, you can rest easy, because zebrafish get along well with most types of aquarium fish. They get along well with catfish, tarakatums, neons, tetras, gouras, laliuses, swordtails, ancistrus, platies, iris, rasboras, mollies, bots, guppies, cockerels, scalars, catfish Corydoras and Labeo. Also, "danichki" get along quite well with snails, shrimps and snails.
Despite the good compatibility of zebrafish with other fish, there are some warnings. If you have a barb or some other type of more aggressive fish living in your aquarium, do not place a veil zebrafish with them, because. more nimble occupants may damage or bite off their veil and long fins.
You can not keep zebrafish in the same aquarium with goldfish, eels, cichlids, astrotonus, discus and Koi.
Diseases of zebrafish
Unfortunately, despite all the charm and unpretentiousness of these fish, they have one flaw. This is a congenital zebrafish disease that appeared from breeders - a curvature of the spine. The main symptoms are raised scales, gills splayed to the side and slightly bulging eyes. Most often they all appear after a fright. A few days later, the central vertebra begins to bend in the zebrafish, and as a result, after a while the fish dies.
A well-known disease of zebrafish is also dropsy. Fish have rearing scales, eyes bulge, belly swells and eventually death occurs.
How to distinguish zebrafish? Male or female zebrafish?
The site kakprosto.ru has instructions on how to distinguish a female from a male zebrafish. I'll bring it here.
Only adults can be distinguished from each other by gender, since young fish are not yet sufficiently formed and are very similar to each other. If gender matters to you, be sure to purchase only adult, fully formed fish, only in this case you can more or less accurately determine which of them is male and which is female. Also make sure that all the fish in the tank are the same age, as this greatly affects their size. Young females can easily be mistaken for males when compared with older fish.
The most accurate criterion for determining the sex of Danio fish is size. Look at a school of fish and try to compare them with each other. Females are usually larger and have a rounded abdomen. Males, on the other hand, are distinguished by a slender physique and are a little short of the size of their girlfriends. This structural feature is associated with the ability to produce caviar and bear fry, which directly depends on the size of the zebrafish female.
Pay attention to the intensity of the color of the fish. The stripes on the body of females are paler and less noticeable, and zebrafish boys are usually brightly colored and shimmer very distinctly. This coloration is evidence of good camouflage of the fish. Pregnant females are more clumsy and slow, so they should not stand out in the sea thickets or against the background of the bottom.
Zebrafish breeding
The aquavitro.org website describes in great detail about zebrafish breeding. I'll post the article here.
Majority research work on the topic of zebrafish reproduction are devoted to maximizing the production of eggs (Laale, 1977), and until now, almost nothing has been known about the reproductive ecology of wild individuals. In the early stages of development, the ovaries act as gonads in zebrafish, and only at 5-7 weeks, with a length of 10-15 mm, male individuals begin to differentiate. However, the final intersecular period and the complete formation of the testes in males ends around the third month of postembryonic development (Devlin & Nagahama, 2002; Maak & Segner, 2003). The genetic mechanisms of sexual determination are unknown. However, there is evidence that the rate of differentiation is affected by food availability and growth rate. In this case, rapidly growing and large individuals become females, and small ones become males (Lawrence, Ebersole & Kesseli, 2007). Based on samples taken from the population in the Brahmaputra River, a natural sex ratio of 1:1 was found (Spence et al., 2007a). Under laboratory conditions, domestic zebrafish breeds breed all year round , while natural - seasonally. However, large females caught in January (i.e., long before the start of the spawning period) had mature eggs, which indicates that the impact on reproduction is not so much the season as the availability of food (Spence et al., 2006a). In addition, the onset of puberty is related to size rather than age; wild and laboratory zebrafish matured being the same size, regardless of their growth rate. Eaton and Farley (1974a) showed that at 25.5°C domestic zebrafish rarely become sexually mature before 75 days, when females are 24.9 mm long and males 23.1 mm. Under laboratory conditions, the first generation of zebrafish is also ready to spawn at a length of approximately 23 mm. Pairs of zebrafish stay together and breed continuously, but spawning cycles are irregular (Eaton & Farley, 1974b). One female for spawning produces small packs containing several hundred eggs. Intervals between spawning vary from 1 to 6 days, with an average of 1.5 days. At the same time, packs of 1-700 eggs are laid (average value 185) (Spence & Smith, 2006). Pack size correlates with female size as well as spawning interval. This interval has been reported to increase with the maturation of the female, from 1.9 days for a one year old to 2.7 days for a 15 month old. In addition, the clutch size increased from 158 to 195, respectively (Eaton & Farley, 1974b). Ovulation depends on how much females are exposed to the male's gonodal pheromones. Males release testis homogenate and a gonadal fraction into the water containing steroidal glucuronides that induce ovulation. Interestingly, anosmic females cauterized with olfactory epithelium did not respond to pheromones (van den Hurk & Lambert, 1983; van den Hurk et al., 1987). Eaton & Farley (1974b). The presence of males for 7 hours in the evening is sufficient for females to start spawning the next morning (Eaton & Farley, 1974b). In isolated females that have been in contact with a male for a period of at least 5 days, spawning is never observed twice. This indicates that all mature eggs are shed in one spawning cycle (Hisaoka & Firlitt, 1962; Eaton & Farley, 1974b). The presence of a male is necessary for the maturation of eggs in females. In isolated or old females, eggs begin to stick together in aggregates, which often leads to their death. Examination of sick individuals showed the presence of rotting eggs stuck to the oviduct and preventing successful mating. Regular contact with the male and spawning excludes the development of necrotic foci. It is interesting that, despite the cyclicity and inconsistency of spawning, females that are in contact with the male a few days before breeding demonstrate better fecundity and egg quality compared to individuals isolated for several days (Gerlach, 2006). This effect is associated with the concentration of the presented pheromones. Both sexes have been shown to secrete pheromones that act as attractants before and during reproduction (Bloom & Perlmutter, 1977). At the same time, the sensitivity to their action is higher during spawning. Zebrafish eggs do not have a sticky shell and are dimersal (bottom). Their diameter is 0.7 mm. Spawning takes place directly over the substrate, which is not prepared in advance. Producers do not care about offspring. Both fertilized and unfertilized eggs are activated upon contact with water and undergo a series of programmed developmental stages. Unfertilized eggs develop into the periyolk space, but the process stops long before the first divisions (Lee, Webb & Miller, 1999). The incubation period at 28.5 °C varies from 48 to 72 hours, depending on the thickness of the chorion and the activity of the muscles of the embryo (Kimmel et al., 1995).
Immediately after hatching, the 3 mm long larvae are attached to the substrate by small secretory cells located on the head (Laale, 1977). Attaching for more high level allows you to reach the surface, access to which is necessary for inflating the swim bladder (Goolish & Okutake 1999). This process is observed by 72 hours after fertilization, after which the juveniles switch to active swimming, feeding, and they develop avoidance behavior (Kimmel et al., 1995). Direct reproduction of zebrafish As you know, spawning of domestic zebrafish depends on the photoperiod (Breder & Rosen, 1966). Individuals exhibit a diurnal activity pattern synchronized with day/night and feeding cycles. The first peak of activity is observed immediately after the start of illumination, and the next two peaks are observed at the beginning of the evening and at the last hour of the daylight hours (Baganz et al., 2005; Plaut, 2000). Spawning is associated with the first peak, usually starts in the first minute after illumination after dark and lasts about an hour (Darrow & Harris, 2004). Field observations have shown that zebrafish breeding in nature is also, for the most part, limited to short periods at dawn (Spence, Ashton & Smith, 2007). However, compared with domesticated individuals, wild individuals have a more pronounced tendency to breed at other times than at dawn. The lengthening of daylight hours may be a factor that triggers reproduction in the natural habitat. The addition of cold water to the aquarium also encourages spawning in the aquarium (Breder & Rosen, 1966). Thus, a decrease in water temperature or an increase in its level serves as an additional signal for zebrafish. In nature, these fish spawn during periods of prolonged rains. Courtship during breeding consists of chasing the female by the male, touching her sides with his muzzle, swimming with spread fins around her in a figure eight or circles, and directing the female to the spawning area. If the female does not follow him, then the male continues to circle from her to the spawning site. Right above the selected substrate, the male swims close to the female, spreads the dorsal and caudal fins around her body so that the genital pores of the individuals approach each other, and the male himself could twitch with high frequency and low amplitude. This behavior triggers the simultaneous release of eggs and sperm. For one spawning, it is repeated several times, and at each stage, the female releases 5-20 eggs. Male courtship is most active in the first 30 minutes, although lasting about an hour, while the female spawns in the first half hour (Darrow & Harris, 2004). Wild zebrafish display similar territorial behavior and courtship (Spence et al. , 2007b). Under natural conditions, males are forced to pursue the female throughout the entire water column, while the female rises to the surface, and then sinks to the bottom to the spawning site. Usually 3-7 individuals are involved in the race. Courtship by the male is triggered by the pheromones of the females. Males, but not females, were attracted to egg extract added to an aquarium (Hurk & Lambert, 1983). Anosmic males (devoid of smell) showed no courtship, while controls courted only ovulating females. In addition, anosmic zebrafish were extremely aggressive, which indicates the inhibitory effect of pheromones on aggression, which is expressed in both sexes during feeding. Danios show a breeding pattern common to many cyprinids; they have group spawning and free scattering of eggs (Breder & Rosen, 1966). Females spawn directly on bare substrate, but if there is a good artificial substrate, such as a plastic surface, they prefer to lay their eggs on it (Spence & Smith, 2005). Some male zebrafish are territorial during spawning (Spence & Smith, 2005). Both territorial and common males display similar courtship behaviors. However, while non-territorial fish pursue females, territorial activity is limited to a few body lengths from the spawning site, from which they drive males away. Territorial aggression has been studied in a study of sex ratios and group density (Spence & Smith, 2005). It turned out that its degree increases depending on the planting density. Courtship behavior increases with the proportion of females, while in the male-dominated group, the degree of courtship decreased to the level observed at low stocking densities. The breeding success of territorial males has been shown to be dependent on stocking density (Spence, Jordan & Smith, 2006). At low densities, territorial individuals produced much more offspring than non-territorial ones. The reverse trend was observed with an increase in the size of the group. Thus, zebrafish males demonstrate two breeding tactics, guarding the site and actively chasing females, the success of which is related to the population size. High stocking densities result in reduced female egg production (Spence & Smith, 2005). This phenomenon is determined by a decrease in the number of eggs in packs released per spawning, rather than with the removal of part of the females from breeding (Spence et al. , 2006b). There are several explanations for this; an increase in male aggression towards each other can affect the competition of females and their access to spawning grounds. In addition, reduced egg production may be due to inhibition by pheromones emitted by other females. It has been shown that females that are under the influence of pheromones of other females prior to spawning are less willing to breed compared to isolated fish (Gerlach, 2006). It should be noted that dominant females produce more eggs (Gerlach, 2006). In studies using large 2*2 meter tanks, avoidance by females of each other and, moreover, exposure to each other's pheromones has been demonstrated (Delaney et al., 2002). Females prefer to be in groups consisting of one or more males than females. Thus, in reproduction, zebrafish plays a role as competition, both among males and among females.
Sexual partner preferences. The relationship between male and female zebrafish
Under natural conditions, it is difficult to determine the preferences of females in those species whose males compete for the opportunity to mate. In this case, the key role is played by the dominance of one or another male. However, there is evidence that females prefer larger males (Pyron, 2003). This is consistent with the data that the body size of bony fish correlates with their dominance in the group (Wootton, 1998). When looking at roe production as a measure of preference, females were found to have roe relative to certain males (Spence & Smith, 2006). However, no correlation was observed with either male dominance or possible female selection (Spence & Smith, 2006). There have been suggestions about the role of pheromones in the choice of a sexual partner. In particular, female zebrafish prefer the scents of foreign males to those of their brothers (Gerlach & Lysiak, 2006). It is possible that two mechanisms of sexual selection, male competition and female preference, simultaneously participate in reproduction. For example, if a female does not want to mate with a dominant male, then he can still do it to the best of his ability. In addition, competition among males for mating may be closely related to competition among females (Gerlach, 2006). In fact, breeding success is similar between male and female zebrafish, and sexual selection plays a minor role (Spence et al., 2006b). This is confirmed by their weak sexual dimorphism.
Substrate Selection The female prefers a specific substrate for spawning. Studies with domesticated and wild individuals in isolated cages found that females preferred gravel bottoms over muddy bottoms (Spence et al., 2007b). Territorial males also tend to protect benthic areas with gravel. This behavior is explained by the much better survival of eggs on a solid substrate, where they are supplied with oxygen and are also protected from cannibalism. Under laboratory conditions, preferences for plant thickets were also revealed, although the latter do not affect the safety of the masonry in any way. However, plants make a significant contribution to increasing the survival of larvae; they provide sites for attachment and help reach the surface for the inflation of the swim bladder (Laale, 1977). AT natural areas where zebrafish are the dominant species, such as floodplain ponds, muddy ground is often present, and fish make their way to spawn in shallow water among vegetation that protects them from predators (Engeszer et al., 2007; Spence et al., 2007b). Thus, the choice of producers is directed to places with better water circulation, where there are no predators. The search for spawning areas is one of the few mechanisms in species that do not show concern for offspring. It helps to increase the survival of masonry and larvae.
Danio fry
Danio fry need live starter food, but substitutes can be dispensed with if necessary. Let's look at the most important points in zebrafish rearing as a tip, when zebrafish fry grow in winter and do not receive live, complete food.
By the time the zebrafish fry swim, you need to be prepared in advance. Danio fry eat well its boiled yolk, and will have to be used as a starter feed. To raise several hundred fry, one will be enough chicken egg. Boil the egg and separate the yolk from it so that the yolk does not deteriorate, it must always be stored in the refrigerator.
Before feeding the fry, take a transparent glass or jar, fill it with water, then take the yolk, cut off the top from it and rub it over the surface of the cut part of the yolk with your index finger or watercolor brush, then rinse the brush or finger in the jar with water.
After when the suspended particles of the yolk settle to the bottom, drain muddy water and repeat this until the water runs clear. Then, carefully and preferably, pour water with yolk to the fry into the aquarium on the compressor sprayer.
Be sure to plant snails in the aquarium, these snails, eating uneaten yolk particles, are of great benefit, keeping the aquarium clean. After 7-10 days, when the fry grow up, they need to be transferred to a larger feed. A good transition would be to scraped beef heart.
It is very important to monitor the water temperature. An increase in water temperature enhances metabolism, in the body of fish, the growth of fry accelerates, but there is a chapel for everything, to cross which means to destroy the fish.
Danio fry grow well at a water temperature of 26 ° C; it is not recommended to raise the water temperature above. As the zebrafish fry grow, the water temperature must be gradually lowered.
Danio fry eventually turn into such beautiful, in this case, pink large zebrafish.
Good luck with danio!
Danio diseases, as well as the causes of their occurrence, will become the main topic of today's conversation. One of the most common aquarium inhabitants can rightly be considered such a fish as.
It is a very unpretentious and popular species, easily recognizable by several horizontal dark stripes running along the body, as well as by its tendency to live in small groups. And with its unpretentiousness, yet this friendly and sociable fish, like any other species, has a tendency to a number of diseases. So, let's begin.
It is a very small relative of the well-known carp. These fish live in the reservoirs of the southeastern corners of Asia.
It is small, about 6-8 cm long. a fish with an elongated body flattened on the sides, the color of which ranges from white to red, and the main external attribute is horizontal stripes along the body. This is a gregarious species, usually adhering to a company of 6-8 individuals.
Prevention of possible health problems in zebrafish
As befits zealous owners, we begin to take care of both the new pet and those residents of the aquarium that we already have, from the very moment we purchase the zebrafish.
It is very important first of all to carefully examine the skin of the fish, in order to make sure that there are no signs of disease or mechanical damage on the body and fin system.
Do not panic if the zebrafish looks too pale, as this may be a consequence of fright from the handover process. It would also be a reasonable precaution to settle the zebrafish in a separate container immediately after the purchase in order to observe its behavior, and only if you are sure that the fish is in a healthy state, you can safely add it to a common aquarium.
Danio has quite reliable health and is quite resistant to diseases. And this is one of the reasons for its popularity among beginners in the aquarium business, because it is really very unpretentious in care.
However, one of the first requirements for its healthy maintenance is the need for artificial aeration of the air inside the aquarium and its high-quality filtration. You can not mention the timeliness of changing the water in the aquarium, since this iron rule is equally significant when keeping almost all aquarium fish.
Also, zebrafish is quite demanding on such a characteristic of water as the level of its acidity. Its value should fluctuate within 6.5-7.5. O possible consequences we will talk about deviations of this parameter from the norm.
Just like the unshakable rule is the inadmissibility of regular overfeeding of fish. After all, it is known that most diseases of both zebrafish and other aquarium fish most often occur when the metabolism of our wards is disturbed.
This is a very important point and the determination of a healthy daily and single dosage when feeding zebrafish should be considered first.
And do not forget to sterilize with boiling water everything that we put in a tank with fish, be it artificial decorations, pebbles or driftwood.
Diseases of zebrafish
Now, actually, about the main thing.
The most frequently encountered include the following:
- bulging eyes;
- obesity;
- trichodinosis;
- growths on the body;
- tuberculosis;
- alkalosis.
bulging eyes
Usually the disease affects the fish during spawning, and it is not always possible to track the onset of symptoms, since one of these is an increase in the abdomen, which can be mistaken for pregnancy in the female.
A few weeks later, a more serious symptom of the disease appears, thanks to which it got its name. The eyes of the fish bulge and eventually fall out, which eventually leads to death.
Obesity
Obesity is a consequence of overfeeding, the prevention of which was discussed earlier. And if we see an increase in the abdomen of a zebrafish, this is of course not a reason to immediately sound the alarm, but it means that it is already necessary to look at the fish. It is possible that there is a metabolic disorder.
Prevention is important here, once again we remind you of the rule - it is better to underfeed the fish than to overfeed.
Trichodinosis
Trichodinosis is already an infectious disease caused by trichodin ciliates.
It occurs as a result of poor-quality disinfection of objects placed in the aquarium. When this disease occurs, the fish often begins to rub against the walls of the aquarium, the shade of the skin also changes, it becomes pale, a dirty coating on the body is noticeable.
As a treatment, the water temperature should be raised to 30 degrees, it is also necessary to use tripaflavin or table salt as baths as part of quarantine.
growths
Growths on the body of zebrafish, in principle, occur infrequently.
However, sometimes this happens, and in this case, the fish should be removed from the general tank to a quarantine tank, where salt baths should be used at a temperature of 28 degrees. The problem should quickly disappear.
Tuberculosis
Yes, it can even hurt like this dangerous disease like tuberculosis or mycobacteriosis.
Another infection fish, which can be brought into the aquarium along with the soil, algae or other infected fish. The most common symptoms include lethargy, lack of appetite in the fish, and even loss of scales.
A very dangerous disease that can be treated only in the initial stages. Main medicine with fish tuberculosis - kanimicin.
It must be mixed with food in a ratio of one to one, that is, 15g. feed give 15 gr. medicinal product.
Mandatory is the quarantine of a sick individual in a separate tank. At the same time, after the end of the treatment, whatever its outcome, it is imperative to carry out a general cleaning and cleaning of the common aquarium with disinfection of all decorative elements.
Alkalosis
Alkalosis or alkaline disease. This disease occurs when the acid-base balance of water is not observed.
They are sensitive to this parameter, and therefore, if your pet shows noticeable anxiety, often jumps out of the water, itches on the bottom or walls of the aquarium and she has a blanching of the skin - all this can be just signs of alkalosis.
To eliminate this problem, you should purchase a pH buffer, which will further maintain the acidity of the water at the desired level.
Conclusion
Thus, we have learned everything you need to know about the most common diseases in zebrafish. As well as got acquainted with their few needs and conditions for the proper maintenance of these wonderful creatures.
It is really unpretentious and caring for it should not be a problem even for a novice aquarium fish lover.