Fish and other aquatic creatures

Danio-rerio - peace-loving restless


Danio rerio has a narrow, long body. This aquarium fish is able to reach 5 cm in length. In the corners of the mouth there is a pair of small antennae directed downwards. The body runs several parallel bands, painted in yellow, yellowish-green or black and blue. The strips begin near the gill covers and stretch across the whole body to the fin. A distinctive feature of females - stripes in the middle of the abdomen thicken, becoming narrower to the tail and head. The female has a more dense abdomen. The rest of the fins are yellowish white.


The zebrafish fish (Danio rerio) was first described by Hamilton in 1822. Homeland fish in Asia, from Pakistan to India, as well as in small quantities in Nepal, Bangladesh and Bhutan.

There are dozens of different variants of color and shape of the fins of the zebrafish aquarium fish. The most popular are voile danios, albinos, danios rerio red, danios pink, and artificially painted species have become popular now. These zebrafish are genetically modified, and are available in bright, fluorescent stains - pink, orange, blue, green. Although this color is very controversial, as it does not look natural, but so far the negative effects of interfering with nature are unknown, and such fish are very popular.

Danio rerio inhabits streams, canals, ponds, rivers. Their habitat depends largely on the time of year. Adult individuals are found in large numbers in the puddles of the rainy season and in the flooded rice fields, where they feed and spawn. After the rainy season, they return to rivers and large bodies of water. In nature, the zebrafish feed on insects, seeds and zooplankton.


Great fish for a common aquarium. Gets along with related species, and with most other aquarium fish. It is better to contain from 5 pieces. Such a flock will respect its hierarchy, and less prone to stress. You can keep with any small and peaceful fish. Danio rerio chase each other, but this behavior is not aggression, but a way of life in a pack. They do not injure or kill other fish.

General information

For the first time, zebrafish began to be imported as aquatic inhabitants since 1905, and now these fish can be found in aquariums around the world. The pledge of popularity of zebrafish is unpretentious content, attractive bright body color and calm character.

The zebrafish is a popular model object in biology for studying embryonic development and vertebrate genes. This is due to the fact that the development of caviar occurs very quickly - in just three days, and the embryos themselves are rather large and hardy, which allows them to perform various manipulations with them.

Zebrafish were the first genetically modified fish. The history of the famous fluorescent fish GloFish began with danios. Just like guppies, danios were honored to fly into space and became one of the objects of study at the orbital station.


The size of danios in the aquarium is 3-6 cm. The body is elegant, stretched in length. The main color of the body is pale yellow, the body is covered with wide dark blue stripes, thereby creating a pattern resembling the color of a zebra. Fins are short, almost transparent, may have a yellow border. Males have a more slender body, in females the abdomen is much thicker. On each lip there is a pair of whiskers, which are usually tightly pressed, therefore invisible.

In addition to the natural color, there are other color variations. Pink danios - different color stripes, they are bright pink fish.

Pink danio rerio

Leopard danios - has a spotty color, resembling a pattern on the body of a famous predator.

Leopard Danio

Danio rerio became the first fish with a changed genotype, due to which bright fluorescent forms were obtained: pink, green, blue, orange.

Glofish danio rerio

There are also voile varieties, characterized by a strong development of fins.


The homeland of Danio-rerio is the countries of South Asia. The wide range of this species includes Pakistan, India, Nepal, Bangladesh. This small and agile fish is found in almost all water bodies: rivers, streams, canals, ponds and lakes. The species is characterized by seasonal habitat change. During the rainy season, adult zebrafish everywhere are found on flooded rice fields and in large puddles. Here they are looking for food and spawn. As soon as the rainy season ends, they prefer to return to large permanent reservoirs.

Care and maintenance

Danio rerio are very hardy ornamental fish, therefore they are often led by beginning aquarists. Indeed, for the maintenance of a minimum flock of danios (5-6 pieces), an aquarium of 30 liters is enough. But the larger the volume, the more comfortable the danios feel. Fish are very mobile, prefer to swim in the upper part of the aquarium. They can jump out of the water, so it is advisable to cover the aquarium with a cover or cover glass.

Danio like clean water, so you need to take care of proper filtration, as well as to organize sufficient aeration. It is desirable to provide good lighting, with suitable lamps the fish will look brighter and more attractive.

The optimal parameters of water for the content: T = 17-25 ° C, pH = 6.7-7.0, GH = 6-15.

Regular water changes are needed - 25-30% of the total. Along the edges of the aquarium, long-stemmed plants are planted, the rest of the space remains under free swimming for danios.

Danio rerio in an aquarium with green plants

Under suitable conditions, a zebrafish can live for 3-4 years.


Danio rerio is one of the most peaceful fish. It can be shared with almost any inhabitants of the aquarium, except those who will consider it as a food object. Do not follow to combine danios with large cichlids, large goldfish, brocade catfish. It is also not recommended to keep active barbs with danios, especially with veil forms, long fins of which will necessarily be bitten.

The best neighbors will be proportionate schooling species: neons, minors, tetras. Perfectly gets on with scalars, swordtails, guppies. Even the fighting fish - cockerels often do not notice in the aquarium the presence of these eternally scurrying neighbors. Any peaceful catfish (corridors, antsistrusy) will also be a good choice for settling in an aquarium with danios, because their food niches are different: somas are bottom fish and danios prefer to swim near the surface of the water.

The natural diet of zebrafish is quite diverse. They are happy to eat small insects and their larvae swimming in water. Do not disdain Danio and small seeds falling from the plants. In terms of aquarium content, these fish are completely unpretentious in the diet. They easily eat live, frozen and dry food. The first two groups of feed are not able to fully meet the nutritional needs of zebrafish, as they are not balanced and do not contain useful vitamins in the right quantity. Therefore, the best choice for feeding zebrafish will be high-quality dry food.

It is worth noting that the danio-rerio food is preferred to be consumed from the surface. Everything that falls to the bottom usually remains outside their field of interest. Also, the feed should be the right size, because the zebrafish mouth is very small.

A wide range of dry food companies Tetra will allow you to easily choose the right diet for feeding zebrafish. These fish prefer to feed from the surface of the water, so it is important that the feed remains on the surface for a long time. TetraMin flocculent feed is excellent on the water, and then begins to slowly sink to the bottom. It consists of more than 40 types of carefully selected raw materials. It provides a complete diet for the daily feeding of all types of ornamental fish. Maintains healthy growth and vitality. Included in the prebiotics improve the work of the gastrointestinal tract.

Alternatively, you can offer small fish floating feed from the MicroFood series in the form of sticks or pellets. Their size is ideal for small mouths of zebrafish. And due to high buoyancy, the feed remains for a long time in the upper layers of water.

Due to the high digestibility of feed, fish produce less waste, which allows the water to remain clean for a long time.

It is necessary to feed the fish several times a day in such a portion of food, which will be eaten by them in a few minutes.

Breeding and breeding

Sexual maturity in danios comes in 3-6 months. Fish can spawn at any time of the year. First you need to choose a pair. Sexual identity can be determined by the shape of the body: in females, the abdomen is more convex than in males.

Female zebrafish

Manufacturers need to be seated in separate aquariums from 10 liters and for several days to feed abundantly with high-protein food, such as bloodworms or daphnia. It is easy to determine the readiness of the female for spawning: the belly becomes convex not only in the anterior part of the body, but also in the anal fin.

As a spawning aquarium, any container with a capacity of 30 liters or more is suitable, it is better not to place the soil in it, it is more convenient to watch the spawning and its development. It is best to lay on the bottom of the grid, which will not allow producers to get to the eggs. It will be useful to place in the spawning plant with small leaves.

The aquarium should be installed on the window sill or near the window, then it is filled with water so that its level is 6-10 cm. The temperature in the center does not play a serious role, but it should not be very low. Producers (usually 2-3 males and one female) are planted in the spawning grounds in the late afternoon.

After sunrise, spawning begins. The fish move rapidly around the aquarium, the males pursue the female, hit her in the abdomen to knock out eggs, and then release milt on her. The frequency of the moths is about 5 minutes, the whole spawning usually ends within an hour.

During one spawning, the female is able to sweep up to 400 eggs. The number depends on the age, size of the female individual, preparedness for spawning.

If there is a situation in the aquarium when the female does not react at all to the males and tries to hide, then the calf probably has not yet ripened. In this case, the female is better to replant for a few days and wait for the full maturation of the eggs. If males do not show any attention to the female, they should also be deposited in a separate container, raise the temperature and feed intensively. When the males start chasing each other, it's time to sit them down on the female, ready to spawn.

At a temperature of 26-28 ° C, the roe ripens within 30-36 hours, with a lower process it can be delayed for a week.

Danio-rerio caviar

After hatching, the fry attach to the walls of the aquarium or aquatic plants, and then gradually move to independent movement. You can feed the fry with infusoria, “living dust”, high-quality dry fry food (for example, TetraMin Baby). Young zebrafish grow very quickly, so the fry need to be transplanted into larger aquariums and sorted by size.

Habitat in nature

The zebrafish fish (Danio rerio) was first described by Hamilton in 1822. Homeland fish in Asia, from Pakistan to India, as well as in small quantities in Nepal, Bangladesh and Bhutan.

There are dozens of different variants of color and shape of the fins of the zebrafish aquarium fish. The most popular are voile danios, albinos, danios rerio red, danios pink, and artificially painted species have become popular now. These zebrafish are genetically modified, and are available in bright, fluorescent stains - pink, orange, blue, green. Although this color is very controversial, as it does not look natural, but so far the negative effects of interfering with nature are unknown, and such fish are very popular.

Danio rerio inhabits streams, canals, ponds, rivers. Their habitat depends largely on the time of year. Adult individuals are found in large numbers in the puddles of the rainy season and in the flooded rice fields, where they feed and spawn. After the rainy season, they return to rivers and large bodies of water. In nature, the zebrafish feed on insects, seeds and zooplankton.

The zebrafish has a graceful, elongated body. Each lip has a pair of whiskers. They rarely reach a length of 6 cm in an aquarium, although in nature they grow somewhat larger. It is believed that in nature, the rério do not live for more than a year, but the duration in the aquarium is from 3 to 4 years. Her body is painted in a very pale yellow color, and covered with wide blue stripes that go to the fins.


An excellent choice for those who want to breed fish for the first time. Spawning in the zebrafish is simple, the fry grow well, and the fry themselves are quite a lot.

Aquarium for breeding should be filled with water about 10 cm, and on the bottom you need to put small-leaved plants, or a protective net. Unfortunately, parents greedily eat their caviar.
The stimulus to spawning is a temperature increase of a couple of degrees, as a rule, spawning begins early in the morning. During spawning, the female will lay off from 300 to 500 eggs, which the male will immediately inseminate. After spawning, parents need to be removed, as they will eat caviar.
Caviar will turn out within two days. Fry are very small and can be easily removed while cleaning the aquarium, so be careful. You need to feed it with egg yolk and infusoria, as it grows, transfer to larger feeds.

Hello! How much danios can I put in a 40 liter aquarium? I have 4 danios and 1 antsistrus, can I still add danios?

Good day! There are several questions:
1) I have two males of pink danios and two females of danios rerio - is it possible to breed them?
2) the article says that you need to keep danios a flock of 5 fish. I have 4 of them, but there are 6 more guppies with whom they get along fine. Do I need to add more danios?

Today I bought a zebrafish 10 individuals. In the aquarium (50l) 5 guppies already live. Will they get along well? Big enough flock? They will not be crowded?

Tell me, please, the filter can not be put into spawning? Malkov "absorb"? 🙂 Do you need oxygen?

Hello! Initially, we had 5 danios rerio. but during the first spawning, the female killed one of the males. Now the fun flock has ceased to be so. Males keep their distance from the female and for some reason migrate to the middle layers of water. play much less. Add a couple of? And what to add - adults. or small? And is it worth adding. considering that the aquarium is filled to the limit. even 3 "lishchnih" teen guppies are there? Plants enough. aeration is. free space to "run" too. everyone else looks healthy. are mobile. and occasionally spawn

Hello, otsadil female and a pair of males, the air, t raised, chase her for two days, but no business.

Hello! And if you put in a spawning airlift filter with an adjustable compressor? After all, he is not very big and fry should not suck?

they immediately spawn and eat with you, you need a fishnet or pebbles so that the caviar falls through them, but the parents do not sneak in, otherwise they will immediately eat

Good day! Tell me please. Dandelions with cornflowers will normally share an aquarium?

Hello, I went to your information for the benefit. Thank you very much for the wonderful videos. I made such fish I really liked

Hello. How long does it take to transfer the danio rerio pink fry to parents and gupiashkas? Thank.

In our aquarium we have 1 bream-shaped barb, 6 guppies and a pair of mollies. The latter, along with brightly colored danios (fluorescent, 4 things) arrived yesterday. Mollies calm, swim there, but danios disappeared the next morning. They were still at about 8 am, and by 12 they were already gone. There is a filter, pebbles are different at the bottom. What could happen, and is it possible to somehow return them, these danios?

open the belly of the barb, you will see there ...

Hello. I had such a problem. Almost every week one fish dies in me, and sometimes 2 happens. Aquarium 40 liters, a good filter, for a small. Oxygen is constantly working. I feed only in the morning, food to improve the color of the fish. Called Rainbow. Sometimes I use daphnia feed. And the food that falls to the bottom, such small dark granules. I clean the walls of the aquarium and filter once a week, changing water 25% every week. I take water from the tap, I clean it through a normal filter, and before pouring it into the aquarium I add Tetra's solution for tap water.
Soil with a siphon once a month I clean. Living plants are generally healthy, but on one bush there are some dark specks on all sheets. Mucus uncovered. Initially, there were 3 lyalius, 3 picilii, ten neons, 2 soms of the corridor, and 3 danios, and 3 guppies. All the fish were alive and healthy. But after three weeks they began to feel one by one. The first to die was a guppy, his belly was gradually growing, I think it was obesity. And in the end he died. Although I do not overfeed fish. All the others have different, but the same symptoms. One fish begins to feel sad, and swims in one place in the lower left corner of the aquarium. И практически не плавает по аквариуму. Неохотно поднимается покушать. Все рыбки в это время плавают по всему аквариуму целиком. Все в своих слоях.The scales and gills of a fish are good, nothing bristles. It looks as usual, but a little paler ... In the striped danios, for example, the fin of the males releases the upper one, as if it were sad. And the stripes at the same time paler Than healthy. The sick fish begins to swim slowly. And when the female guppy died, she seemed to have paralysis, the tail went down, was not at the level of the body, but lower. I otsadil it, but the next day she seemed to convulse, tried to swim, but jerked upside down. .. Help please, I do not know what to do anymore. I have all the rest of the fish.

I also do not have a thermometer in the aquarium, I noticed that when the water is hot, the water is warm. When it gets colder, the water in the aquarium is also colder. Could this affect?

Good afternoon! Faced with an incomprehensible danio problem: a week ago the female danio began to grow in a female danio's belly and reached a solid size. No adverse side effects were observed. He considered that he was preparing to spawn, but the males did not show any activity. A day ago, the female began to swim on her side and sink down with her tail if she stopped working with fins. The scales are visually normal, there is no glaucia, it is trying to move actively, even more rushing, very often working with gills. It looks like a disease, but microbacteriosis apparently has slightly different signs. And today, three samyzyschitsya under the anal fin began to show activity to the female in such a state, rubbing, chasing the bank. As a result, it is not clear, sick, wheeled or all together? What is your opinion based on personal experience? Maybe otsadit, so as not to infect others?
P.S. During the last two months, six danios consistently died from some rickets — the spine was crooked, and the belly “stuck” to the back. He took young half a year ago in "4 paws". I turned to the seller, he replied - factory defect, genetics.
Quite recently, small white, about 2 mm, fast worms on the front glass, similar to worms, appeared (noticed once at night when I had to turn on the light abruptly), probably with live food zan.
Water in the room, t

26-27 C, the test slightly exceeds NO3. Live plants.

Oxygen is needed, and the filter can be put as a fry will float


After reviewing the photo, you can guess that these fish have many varieties. However, only danio rerio was subjected to genetic modification. Still such representatives are called GloFish. A fluorescent element was introduced into the genes of these fish. Thus did the zebrafish appear pink, green and orange. Differ in bright coloring which becomes more intensive under the influence of an ultraviolet. The content and behavior of this variety is no different from the classic.

The red color was obtained by the introduction of coral DNA, the green fish became due to the jellyfish genes. A yellow-orange obtained representatives with these two DNAs.

Content and feeding

The content of danios rerio is completely unpretentious. They can perfectly accommodate even in nano aquariums. For a flock of 5 individuals only 5 liters are required. Hold in the upper layers of water and love to jump, so the tank must be closed with a lid. The fishes are very playful, but they always stick together, which can be seen even from the photo.

Be sure to plant the plants, but place them in one corner so that the danios have enough space for swimming. Provide good lighting.

Water requirements:

  • Temperature - from 18 to 26 degrees.
  • Ph - from 6.6 to 7.4.

In their natural habitat, the fish feed on the seeds of plants that have got into the water, small insects and their larvae. At home they become almost omnivorous. They are suitable for any live, frozen or artificial feed. Preference is given to Artemia and the pipe worker. Note that the pieces of food they catch only from the surface of the water. Everything that sinks to the bottom will remain there.

Who to choose as neighbors?

The danio rerio aquarium fish is completely non-aggressive, so it can get along with almost any neighbors. In the pack, they can chase each other, but this is a manifestation of hierarchical relations that do not apply to other species. Danio is perfect for keeping in the general aquarium. Do not cause any harm even slow and calm species. The main thing is that among the neighbors there are no predators who could perceive small fish as food. The photo shows that danios are extremely miniature, but, due to their speed and non-conflict, they can even get along with such aggressive neighbors as cichlids (medium-sized), gourami, and scalars.

Excellent combined with small fish - guppies, macropods, rasbora. Also suitable for the role of neighbors ternation, cardinals and nanostomus.


Zebrafish breeding is an easy process that even a novice can handle. Fish reach sexual maturity already in 4-6 months. And you can start breeding them at any time of the year.

Before spawning danios are moved to a large aquarium (from 10 liters), the water temperature should be above 20 ° C. Feed the fish need plenty of. For these purposes, perfect red daphnia and bloodworm. Feed must be alive.

Soil in spawning is optional. Many aquarists specially select containers with a transparent bottom to monitor spawning and the formation of larvae. But you can not leave it completely empty. The bottom is carpeted with bog or futinalis, which is necessarily pressed down with something. Water for spawning is taken from the common aquarium, where the fish constantly live. Be sure to install a siphon in the tank. It is better to place the aquarium on the windowsill in order to have access to direct sunlight.

For breeding, several males and one female are selected. Put them in spawning better in the evening. During the night they will be able to settle in a new place, and in the morning, when it dawns, spawning begins.


We continue the theme of "danio rerio - reproduction". It is very interesting to watch the spawning process. Fish move extremely quickly through the aquarium, literally fly. When the male manages to catch up the female, he hits her in the belly, from which the eggs fly, and he himself releases the milt. Spawning lasts about an hour. During this time several marks may occur with intervals of 6-8 minutes. During this time period, the female can lay from 60 to 400 eggs.

In the spawning can be placed and two females, but then the offspring will be smaller. Therefore, if you want to get more fry, prepare several aquariums for breeding.

When spawning is over, males and females are removed from the “nest” and are seated in different containers. The label is repeated in a week, otherwise the caviar will ripen. For one female, up to 6 litters are normal. If, during spawning, she hides from the male, then her calf is not yet ready or has already matured. In any case, the fish are left in spawning for another two days.

The incubation period lasts two days. Then fry are born, they can be seen in the photo below. They are very small, so you need to be extremely careful when cleaning the aquarium. At first, the young feed on infusoria and egg yolk. As the kids grow, they transfer to more food.