Danio fish


Popular types of danios fish

Danio (lat. Danio) is a genus of small freshwater fish of the carp family. Many wild species of danios are found in water bodies in Southeast Asia, preferring stagnant water, or slow-flowing rivers and streams. Danios are characterized by oblong symmetry of the body, flattened on the sides, and variegated color scales. Wild species can grow in size 10-15 cm in length. In some danios the upper jaw has a mustache. The diet of wild fish - plankton, insects and their larvae.

Danio are peaceful and mobile fishes that swim in flocks of 6-8 individuals. Do not show aggression to relatives and other fish. Males have a small body, unlike females. They become sexually mature at the age of 6-12 months, depending on the environmental conditions. All danios are fishes. Life expectancy in captivity: 3-5 years, can live up to 6 years.

Varieties of Danio: Pearl, Hopra, Dangila

Danio albolineatus, or pearl danio - is found in freshwater bodies of the island of Sumatra, Malaysia, Thailand, Indonesia, Burma, Malacca. It can be seen in the rice fields, in streams and canals. The pearl danio has a body of translucent tone, oblong, 5-7 cm in length. The color of scales is gray-blue with a pearly shimmer.

On the tail begins a red-orange horizontal line that reaches the middle of the body. The color of the fins is transparent with a green tint; there may be specimens with yellowish or reddish fins. Pearl daniosus is often confused with danios pink, however, the morphological characteristics of these species are different.

Danio firefly, or Khopra (Chopra) - a fish native to Northern Burma, the Irrawaddy River. It has a bright body color with a lemon-orange color. The body is miniature, 3 cm in length. The fins are long, with yellow stripes at their base. An orange horizontal strip is seen on the body of sexually mature females.

Danio dangila, Danio Dangila, or Olive Danio is a fish native to India, Bangladesh, Burma and Nepal. Dangila is a relatively large species of Danio, wild individuals grow up to 15 cm in length, aquarium - up to 10 cm. The body is elongated, also flattened on the sides, with dark spots behind the gills. Above the upper jaw there is a pair of long antennae.

Look at the danios danila in the aquarium.

The main color of scales is pinkish-brown, the color may vary depending on the spectrum of light and the geography of distribution of the wild species. There are dark patches on the body. Aquarium dugil swims in the upper and middle layers of water, but they are able to swim in the bottom layers. In sexually mature females, a rounded abdomen is distinguished, the color of their bodies is faded, unlike males.

Danio orange, Malabar, rerio

Danio kyathit (kiatite), danio orange, or orange-fingered - was brought from Burma. Characterized by an elongated body, the size of 4.5-5 cm in length. The dorsal, ventral, and caudal fins have an orange edging.

The color of scales and fins in males is more expressive, and is saturated with pigment during the spawning period. There is an orange part of the body between the gills and ventral fins of males. Kiatite can swim in the middle and bottom layer of the aquarium, unlike its related species danios.

Malabar Danio is a relatively large variety of Danio, found in nature in the freshwater rivers of India and on the island of Sri Lanka. The length of the body is 10-12 cm, the body is rounded, elongated. The color of the scales is silver-blue, 2 blue lines run along the body, the upper one ends on the tail. Between these blue stripes there are 2 more stripes of golden color, and yellow-golden spots can be seen behind the gill covers.

The hue of the ventral and anal fins is pink, and the dorsal and caudal fin is blue. The color of the ventral and anal fin is characterized by sex differences - in males these fins are pink, in females they are pale pink, and they have a rounded tummy. Representatives of this species of zebrafish become sexually mature at the age of one year. Duration of spawning several hours, occurs in the morning. The female brings 1000-2000 eggs.

Danio rerio (Brachydanio rerio, Danio rerio), or zebra fish - wild fishes of this species are found in the rivers of India and Pakistan. One of the most unpretentious and popular aquarium pets. Body size 4-5 cm, on the body there are oblong stripes of lemon-yellow color, the main tone of scales is bluish-silver with violet-blue stripes. Young fish have short fins, with the achievement of puberty they become longer. There may be a yellow border at the edges of the fins.

Look at the flock of danios rerio.

Danio Pink, Danio Thai (Blue)

Danio roseus, or pink danio - a beautiful fish from the island of Sumatra. The length of the body leaves 5-6 cm. The symmetry of the body is elongated, flattened on the sides. Above the upper jaw there is a pair of small antennae. The back color is gray-olive, the lateral part of the body is gray-green, or silver. When illuminated, the color of scales may be contrasted with purple, blue and green hues. On the body there is a red-pink horizontal strip passing through the body, with age it may disappear. Dorsal fin translucent, greenish-yellow. The anal fin can be red or bright orange, the tail fin is green. Males are colored more intensely, during reproduction, the scales are saturated with bright crimson pigment, and a red speck appears in the middle of the tail. In females at this time, the belly is rounded, they look dense.

Danio Blue, Danio Kerry, or Thai Danio - comes from freshwater rivers of northern Thailand. Small fish (4-5 cm) are also characterized by gregarious behavior. The body is translucent, oblong and flattened on the sides, there are long antennae above the upper lip. The color of the scales may be gray-blue, or have a golden shimmer during the breeding season. Abdomen blue, along the body are horizontal gold stripes. The fins of the fish are transparent, with a yellowish-green shimmer. The color of the males is bright, their body is angular. Females are distinguished by a gray and faded body color.

Danio transgenic, fluorescent (Glofish)

The artificially derived Danio breed was obtained as a result of a selection of zebrafish with the introduction of jellyfish DNA fragments into the fish gene. The genes of the Crystal jellyfish, which synthesize green fluorescent protein, have entered the fish genome. In ultraviolet light, fish acquire a bright, glowing body color. In some countries, these Danio decided to use as indicators of water pollution - in the presence of toxic substances in the water, the fish changed the color of the skin.

When a representative of a fish company that specializes in the breeding and sale of aquarium danio fish, saw these glowing fish, decided to create several more transgenic Danio. In the danio rerio genes, the coral Discocotinia genes were introduced. It turned out the fish with a red glow of the body, and with the addition of the gene of jellyfish and corals - the fish with a yellow glow. The last breed was named "Night Pearl". In 2003, the first copies of Glofish were on sale, which could be bought for home aquariums.

If you compare "Glofish" with the progenitors, Danio rerio, then the first ones like warmer water with a temperature of 27-28 degrees Celsius. But transgenic fish contain, feed, breed can be as well as other Danio. Caring for them is quite simple, at night their body will flicker with an incredible glow. Their nature is peaceful, calm, they are non-aggressive towards other fish. Body size reaches 5-7 cm, fins are short and translucent.

Some countries have banned the import and sale of Glofish because of the genetically modified origin of this breed. Despite the different types of prohibitions, they are still sold and distributed. They do not harm the aquarium and the ecosystem.

Danio rerio: content, compatibility, reproduction, photo-video review

Danio rerio brachydanio rerio

Detachment, family: Carp.

Comfortable water temperature: 20-24 ° C.

Ph: ph 6.5-7.5.

Aggressiveness: not aggressive.

Compatibility Danio rerio: compatible with all "peaceful fish": danios, terence, minor, tetra, scalar, soma, etc.

Useful tips: Very common fish. Fishes quick and gregarious. They can coexist with many species of fish, even with fish of medium and increased aggression: scalar, goura and even with small cichlids.


Fish Danio rerio lives in slowly flowing water bodies of Southeast Asia.

A small fish with a body length of up to 4.5 cm. The body is elongated, flattened laterally. Along the body of the fish are alternating blue and white stripes that start from the gill covers and end on the tail fin. The tail and anal fins are striped. The remaining fins are clear, colorless.

Fish are kept in the aquarium flock (from 6 copies). It is possible to contain Danio rerio in the general aquarium with a length of 60 cm and a volume of 20 liters. The decorations of the aquarium can act - thickets and floating plants, stones, snags. Fishes also need free space for swimming.

Comfortable parameters of water for the content of zebrafish: temperature 20-24 ° С, dh up to 15 °, ph 6.5-7.5, regular weekly water changes (1/5) will have a positive effect on the health of the fish.

Feeding Danio Aquarium Fish must be correct: balanced, diverse. This fundamental rule is the key to successful keeping of any fish, be it guppies or astronotuses. Article "How and how much to feed aquarium fish" talks in detail about this, it outlines the basic principles of the diet and feeding regime of fish.

In this article, we note the most important thing - feeding fish should not be monotonous; both dry and live food should be included in the diet. In addition, you need to take into account the gastronomic preferences of a particular fish and, depending on this, include in its diet ration either with the highest protein content or vice versa with vegetable ingredients.

Popular and popular feed for fish, of course, are dry food. For example, hourly and everywhere can be found on the aquarium shelves of food company "Tetra" - the leader of the Russian market, in fact, the range of feeds of this company is striking. In the "gastronomic arsenal" of Tetra are included as individual feeds for a certain type of fish: for goldfish, for cichlids, for loricarids, guppies, labyrinths, arovan, discus, etc. Also, Tetra has developed specialized foods, for example, for enhancing color, fortified or for feeding fry. Detailed information on all Tetra feeds, you can find on the official website of the company - here.

It should be noted that when buying any dry food, you should pay attention to the date of its production and shelf life, try not to buy food by weight, and also keep the food in a closed state - this will help avoid the development of pathogenic flora in it.

Reproduction takes place without any difficulties. But the fish is the fawning. Therefore, without preliminary preparation is not enough.

About a week before spawning, males should be separated from females and kept separate from each other. The female from the male can be distinguished by a more rounded abdomen and a less saturated color of the yellow-green stripes. Before spawning, producers need to be abundantly fed, preferably with a chowder.

Spawning can serve as an aquarium with a volume of 10 liters (in extreme cases - the usual three-liter jar). Cover the bottom with luster, peristolistnikom or fontinalis. I also had positive results with the usual elodea. Plants gently press down with small pebbles so that they do not rise to the surface. You can also use a grid that has cells of such size that the eggs freely pass through them. But its cells should be cramped for manufacturers.

Water should be fresh settled for at least 2 days. Temperature 24 - 26 degrees Celsius. She poured a layer of about 5 centimeters above the plants.

In the evening two males (maybe three) and one female are planted in the spawning prepared in this way. The readiness of the female for breeding is indicated by a thickened abdomen near the anal fin. Capacity put on a well-lit window. Zebrafish reproduction begins in the morning when the first rays of the sun fall on the breeding ground. The female can sweep 50 to 400 eggs at a time.

If spawning did not happen on the first morning, the producers need to be held in the spawning area for another day after feeding them with small bloodworms. If now there was no spawning. That males need to be transplanted from females and after 3-4 days to plant again to spawn.

There is one peculiarity - if the spawned female is not planted again to spawn in 7-10 days, then it can lose the ability to reproduce.

After the end of spawning, manufacturers should be precipitated, and half of the water should be replaced with fresh settled, of the same composition, of the same temperature.

After about 3-4 days from the eggs the larvae appear, which for several days hang on the glass jars. They have the appearance of strings with thickened heads. After a few days, the fry begin to swim. As soon as the fry swim they need to be given ciliates, rotifers, nauplii Artemia. If the feed is very tense, you can feed up boiled egg yolk boiled in steep water. You only need to give it very carefully in small portions, as it spoils the aquatic environment very much. The results will be somewhat worse.

As the fry grows, food for them can and should be enlarged. For the older fry, small crustaceans can be given - daphnia, cyclops. Grown fry as they grow must be transferred to a more spacious vessel.

Glofish - These are genetically modified fluorescent fish.

The first fish that have been mutated is Danio rerio. As a result of experiments received fish with red, green and orange fluorescent color, which becomes brighter and more intense with ultraviolet light. Transgenic fish are as unpretentious in content and peaceful as the "natural" individuals. Despite the spread of opinion about the sterility or sterilization of genetically modified fish for the purpose of not spreading them in natural waters, you can get quite healthy and viable offspring from GloFish. Commission on the restriction of the use of genetic technologies breeding, exchange and sale of fluorescent fish GloFish is strictly prohibited.

How did it happen: fragments of jellyfish and red coral DNA are embedded in their DNA. Danio with a jellyfish DNA fragment is green, with coral DNA is red, and the fish in which both DNA fragments are present are yellow. Due to the presence of these alien DNA fish glow brightly in the ultraviolet light.

Photo compilation with danio rerio

Interesting video about danio rerio

Danio pink: content and reproduction

It is believed that to breed and maintain such an ornamental fish, such as danios pink, may even be a novice in the aquarium business. Danio - representatives of a large family of carp - really unpretentious, they are frequent inhabitants of artificial home reservoirs. Still, the features of their reproduction, behavior, feeding, you need to know before they are in the aquarium.


Some call this beautiful fish and another name danio pearl. Indeed, in bright light, her body shimmers like nacre.

Like all typical carp representatives, the danio pink body is flattened laterally, two pairs of whiskers are located at the edges of the mouth, on the sides and on the back of the scale with a brilliant color of a complex combination of colors: blue, olive, gray, green.

The abdomen is pink in color, and in mature males it becomes saturated with bright pink.

Adult aquarium fish reaches 5 centimeters in length, and in nature there are specimens up to 8 centimeters.

The natural habitat of danios is quite large: from India to the countries of Indochina, where the flocks of these fish live in the cool water of small rivers and streams.

Conditions of detention

Excellent swimmers, rapidly and abruptly changing the direction of movement, danios love space and usually live in the middle part of the water.

Aquarium. Therefore, a long rectangular aquarium with a capacity of at least 50 liters is best suited for their maintenance. It is possible to lay small pebbles or coarse-grained river sand on its bottom, and also to dissolve small-leaved aquatic plants. For danios pink it will be exactly what you need.

Lighting. It is necessary to take care of him. If you place the fluorescent lamp closer to the front wall of the aquarium, the appearance of the pink-pearl moving creatures will only benefit from this. It is also recommended to illuminate the aquarium with natural sunlight, at least 2-3 hours a day.

Temperature. There are no special temperature requirements for these fish. They feel good in water of room temperature (from +20 to +23 degrees) with low salt content.

Oxygen access. An indispensable condition is a good constant aeration of water, its high-quality cleaning and periodic replacement. It is advisable to replace from 25 to 30% of the aquatic environment once a week, at least.

Security. The aquarium, where danio pink flocks live, must always be kept under the hood (between the water surface and the lamp), as these frisky decorative carp are not only excellent swimmers, but also excellent jumpers in height.


Danio is a schooling fish, and they are completely non-aggressive towards other inhabitants of the aquarium.

A flock of 7-10 fish, quickly dissecting the water space, does not harm anyone.

Active pink-pearl specimens quite peacefully coexist with such ornamental fish as

  • swordtails,
  • gourami of all kinds
  • loaches,
  • mollies and others.

How to feed

But the appetite for Danio pink is excellent just because of their agility. They are happy to eat any common types of food:

  • bloodworm,
  • Daphnia
  • small insects and their larvae,
  • small plant seeds,
  • frozen mine,
  • as well as ready-made branded feed TetraMin.

True, the abuse of commercial feed should not be.

Difference by gender

Males and females have almost the same color. However, it is still possible to distinguish them, but only at a more mature age.

Females are almost always slightly larger and slower than males. Their coloring is more faded and muffled.

Males, on the contrary, have a slender and bright body with expressive stripes or spots on it.


For breeding danios pink, you definitely need a separate aquarium at the rate of 15 liters of water per 1 individual, since in the total capacity the caviar will be quickly eaten.

The requirement for the amount of water due to the fact that in the mating season, and especially during spawning, the fish are actively moving in different directions.

In order for pets to not get hurt, the bottom of the pit should not contain large stones and soil with sharp edges, it is better to cover it with peristristis, Canadian elodea or moss. And in order for plants not to emerge, you can put small pebbles.

Clean, defended water (2 days is enough) in the spawning area should be made a little warmer than in the main aquarium, raising its temperature to +28 degrees. In this case, the liquid should be subjected to light aeration.

In the breeding ground, first one female is deposited, it is well fed, mainly in the root, since it contains the necessary nutrients and there is no fat at all. As soon as the female's tummy is strongly rounded (in 10-14 days), two males are placed on it. At night, the light turns off.

The next morning, the female begins spawning, which can last up to several hours. At this time, she randomly tossed from side to side, leaving behind her caviar.

One litter contains from 100 to 200 white-colored eggs, which descend to the bottom of the spawn through the grid cells.

Aeration is necessary to continue, constant lighting is necessary.

The incubation period lasts up to three days. After this time, barely visible fry begin to vyklevyvatsya. After another day, when they are already moving, you can start feeding, gradually increasing the dose as the offspring grows.

In the initial period, live dust is used as food: the smallest plankton, ciliates, rotifers. Suit and dry egg yolk. As the babies grow up, they switch to feeding on larger meals.

After about 5 weeks, when the young growth reaches a size of 2-2.5 cm, it can be transplanted into a common aquarium.

For more than 100 years, aquarists in many countries are happy to keep and breed pink danios. Watch for their movement and color overflow can be hours. Unpretentious bright tomboy rightly are the favorites of both adults and children.

Video about the pink danios, devoted to the basic rules of the content:

Danio - maintenance and care

Danio rerio is one of the most popular and amusing species of fish, differing from the others in its ability to jump out of the water.

However, the maintenance and care of danios is quite simple, these fish are unpretentious and non-conflict. Thanks to their amazing color (there are 12 types of them), they always become an ornament to any aquarium. In our article we will share with you tips on the maintenance and care of danios, so that your tiny pets always feel good and continue to delight you with their playfulness and beauty for a long time.

Care and maintenance of danios at home

Since in the event of an approach of danger, these fish can jump out of the water directly 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 about 3-4 cm, so that jumping out, the fish will not hit the hard surface and not hurt.

Keeping danios and caring for them at home is quite simple. Fishes mostly 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. The optimal water temperature for danios should be around 24 ° C. Although its small changes, these fish will respond quite calmly.

If you want to breed danios yourself, then you need to prepare another aquarium - spawning. The thickness of the water in it should be no more than 6-8 cm. After spawning, the female and the male are seated in different aquariums, after which after 7 days the female is started again for repeated spawning, in order to avoid her infertility.

Danio feeding is also an important process. For this suitable for this type of dry or live food. It is very important that the food be crushed, otherwise the fish will not be able to swallow large pieces.

Danio compatibility with other fish

If you have replenished your homemade living area with these beautiful water dwellers, you can be calm, because danios get along well with most types of aquarium fish. They get along well with catfish, tarakatum, neon, tetra, gourami, lyalius, swordtails, antsistrusy, patzilii, rainbows, ramings, mollies, battles, guppies, cockerels, scalars, catfish Koridorasy and labo. Also "Danički" get along quite well with snails, shrimps and ampouleries.

Despite the good danios compatibility with other fish, there are some caveats. If you have a barb or some other kind of more aggressive fish living in your tank, don’t live with them a voile danios, because more nimble tenants can damage or bite off their veil and long fins.

You cannot keep danios in the same aquarium with goldfish, eels, cichlids, astrotonus, discus and Koi carps.

Diseases danio rerio

Unfortunately, despite all the charm and unpretentiousness of these fish, they have one flaw. This is a congenital danios disease, which appeared from breeders - a curved spine. The main symptoms are rearing scales, splayed toward the gills and slightly bulging eyes. More often they all appear after fright. A few days later, the central vertebra starts to bend near the zebrafish, and as a result, after a while the fish dies.

A well-known danios disease is also dropsy. In fish, rearing scales appear, eyes bulge, the belly swells and eventually death occurs.

Differences between sexes in pink danios and rerios

Danio is one of the most popular aquarium fish that has been loved by many. If you decide to breed them at home, you should buy healthy fish, a female and several males, or 2 females and twice as many males. At a young age, the sex differences in fishes are mild, and before spawning, they will become more noticeable.

How to know the sex of the fish - the main differences

Brachydanio rerio, or danio rerio - freshwater fish of the carp family. They live in the reservoirs of Southeast Asia, where the water is relatively warm. The standard color of danio rerio is bluish-green, on the body there are several horizontal stripes of yellowish tint. Characterized by schooling behavior, so it is difficult to distinguish the sex of a fish in a flock. All Brachydanio rerio breeds have the same sex differences.

If you are new to the aquarium business, buying Danio rerio or another type of Danio can be a puzzle. In the otsadnik, where they will be sold, can swim a large flock of fish. You can buy all at once, or 5-6 fish at once, 8-10 fish. Surely, among all there are at least a few males or females. Young zebrafish are very similar to each other, they do not have sexual dimorphism. The color of the body is identical, as are the sizes, the fins are commensurate.

Watch a video on how to determine the gender of danios.

When you purchased a flock of fish, then in a few months they will form a body. Adults, sexually mature danios will differ in size. The main difference between a male and a female is the difference in body length. In the female it is large, rounded, and the male is distinguished by the angular symmetry of the body, thin and shortened.

Do not forget to pay attention to the color scales. The zebrafish male has horizontal stripes brighter than the female. This feature is perfectly visible during the spawning period, when a female fish looks for a partner with a brighter color. Females are always faded, they do not need to attract attention to themselves. Their task is to carry caviar. As for this type of fish, like pink danios, the male can become very bright during spawning, the body color will be bright pink, even cherry.

It is also worth studying the behavior of fish during the mating season. The behavior of males and females is a clear difference that characterizes their social roles. The females are usually sluggish, their movements are smooth and cautious, and the males swim abruptly, chaotically around the female, develop a high swimming speed. In preparation for spawning, the males are pushing the female into the belly, helping her to release the eggs.

One of the easiest ways to determine the type of pink danios and danios rerio is to look at the anal fin of a small fish. In the male it is pointed, short, the so-called "gonopody", through which the milt will be released. In females, anal fin is round and large.

Look at the flock of danios rerio in the aquarium.

It is important to learn to distinguish between the sex, if you plan to breed Brachydanio. If you have any doubts as to what sex your pets are, conduct the following type of analysis: precipitate 4-6 fish into separate tanks with infused and prepared water, where the temperature is 22-24 ° C, and look at their behavior. In a few days, different-sex fish can prepare for spawning - females will round off, and males will begin to compete with each other. In one of the containers there will definitely be heterosexual individuals. Remember that the female produces a lot of caviar - up to 2000 pieces.

Additional recommendations

  1. Good lighting and dense vegetation, soil can help you in determining the floor of the fish. The light spectrum emphasizes the color of scales, and it will be easier to understand which fish is brighter and which one is more faded.
  2. It is advisable to buy adults who have already formed fish from proven razvodchiki. When breeding fish at home, watch the growth of fry, their behavior. Some females grow faster than males.
  3. If a pink danios lives in an aquarium, then the floor is easier to determine. Horizontal lines on the body of males are very bright, give a blue color, the scales are saturated with dark pink pigment, which is noticeable during spawning.
  4. In the male pink danio, the caudal and anal fin is green, while the anal fin is red.
  5. Why do females need faded body color? During pregnancy, they need to disguise their body to hide from potential enemies. Pregnant females are very slow and clumsy, so they can mimic the color of algae and soil.
  6. A spawn ready to spawn will always be large. A small, angular body indicates that she is still young.
  7. Malabar Danio is one of the largest representatives of Danio. Sex differences are noticeable at a young age - the body of the female reaches the size of 10 cm, the male - 6-8 cm.
  8. Another way to find out the difference is that male zebrafish can periodically chase females, which is not a preparation for spawning. Such behavior is motivated by the observance of hierarchy in the flock.

What is interesting zebrafish?


Danio rerio (Danio rerio) lives in aquariums for a long time. They were successfully kept and bred in large numbers as early as the nineteenth century. Probably even then, for their unusual coloring, these fish were called "ladies' stockings". Nowadays aquarists usually call danios petting "tribute". And indeed, danyushki can not help but like. They are cheerful and perky, always in motion, forming an endless round dance in an aquarium. "Fire-fish" - so said one of my acquaintance breeder of aquarium fish about energetic and healthy fish. By Danio, this expression fits perfectly.
In the content of all zebrafish unpretentious, although these extremely mobile fish need enough space for swimming. Feed is preferred live, corresponding to the size of the fish. Content temperature? ordinary room, in preparation for spawning? 22? 24? C spawning? 24? 26? C. 7–10 days before spawning, males and females are kept separately. Gender differences characterize the shape of the body of the fish, the males are more progonist and narrow-emaciated compared to their fat-belly friends. Ordinary tap water is quite suitable for spawning, settling for one or two days. The water level in the spawning area is 6? 10 cm. The soil in the spawning area is not mandatory, and its bottom is covered with small-leaved plants, pressing them with pebbles. Producers, two males and one female, are planted in the spawning grounds in the evening, and spawning usually occurs with the rising of the sun, when the temperature rises to the spawning norm. Adult fish eat their eggs, so after spawning they need to be removed. Caviar develops about two days, the larval stage passes in immobility. When the fry begin to swim, they are fed infusoria or other micro-feed, in the worst case? egg powder. As they grow, the fry switch to feeding on small cyclops, daphnias, a pipe-worker and a bloodworm. Danio rerio bred domestic aquarists from the beginning of the century. These are small, about 5 cm, elegant fish, whose bodies and fins are covered with alternating longitudinal stripes of dark blue and golden colors. For this coloring, they got the usual Russian name? ladies' stockings? . The fishes are peaceful and can be a decoration of both a specific and a common aquarium.
The dotted danios are similar in size and pattern to bands, but, by contrast, the lower body and anal fin are not covered with stripes, but with blue-blue dots. These fishes easily interbreed with zebrafish, so that in the litters of hybrid fish there is often a scatter of signs of one or another species. Pink danios are somewhat larger than the ones described above, but the same slim and mobile fish. The body of this fish is painted in bluish-pink tones, sparkling in reflected light. This is aggravated by the liveliness of the fishes, whose flock is in constant motion. Conditions of detention and breeding? common to the whole race. Easily crossed with other types of danios.
Leopard danios slightly smaller than the previous one, is distinguished by its coloring. On the golden-yellow background, the whole body of these fish is colored with dark spots, for which they got their name.


Danio fish used for cancer research
The eyes of scientists are again turning to the striped danios (Brachydanio rerio, zebrafish). Only if before it was going to be used as an indicator of the degree of contamination of water, now we are talking about the treatment of cancer.
The fact is that the genome of this fish has about 30 thousand genes, that is, about the same as in humans. As it turns out, many of these genes function in exactly the same way as humans.
A team of American researchers have stimulated the development of acute lymphoblastic leukemia in this fish in order to find out which genes speed up or slow down the spread of this disease.
Scientists have linked the Myc gene, which plays an important role in the development of leukemia and lymphoma in humans, with the fish gene acting exclusively in lymphoid cells, the very ones that are affected by leukemia.
Then a third gene was added to them, which made the diseased cells glow green with fluorescent light.
This combination of three genes was introduced into the zebrafish embryos. Thus, subsequently, the disease-causing genes were found in every cell of the body.
Leukemia began in all fish that were injected with the Myc gene.
Making zebrafish genetically programmed for leukemia will allow researchers to identify hundreds of genes that, in mutated form, affect the progression of the disease. Myc, as it is not difficult to understand, is not the only one involved in this.

Roman Grudtsin

The genus danios consists of numerous species. The generic name "Danio" refers not only to this genus, but also to the Devario genus. The genus Danio comes from rivers with fresh running water and streams in south-east Asia: India, Bhutan, Pakistan, Bangladesh and other countries. Many species have a bright color. Some species in remote areas of Myanmar are not yet open, so they do not have scientific names. The danios have two pairs of long whiskers, which diverge horizontally. The only exceptions are three types with vertically arranged whiskers. The length of the whiskers is from 4 to 15 cm. Life expectancy from a year to three.
In the wild, zebrafish feed on small aquatic insects, crustaceans, worms and plankton. In the aquarium, they are omnivores and easily digest dry food. Before spawning, zebrafish need to be enriched with fresh food, such as Moin and Cyclops. Some species of danios may well have lunch with small fish that fit in their mouths or someone’s caviar. Друг на друга рыбки никогда не нападают, так, могут иногда укусить чужой хвост от избытка чувств. Они предпочитают держаться группами их шести или более рыб.
Несмотря на то, что данио совсем неприхотливы касательно условий проживания и теоретически могут жить даже в минимальном аквариуме, лучше приобрести для них "дом" побольше для того, чтобы они наслаждались активным плаванием, и оснастить его воздушным фильтром. В оригинальной среде обитания эти рыбки любят скакать по водяным порогам и при наличии средств это удовольствие им можно устроить и дома. In order to prevent the fish from jumping out of the aquarium during the game, it must be closed with a lid.
Danio mating games can also be held in the general aquarium. During mating games, the fish are not pugnacious, females do not suffer from the excessive influence of males during pregnancy. In order for the eggs to hatch, it will take two to three days, and the adults need to be removed at this time; they tend to eat the newly emerged fry.
In terms of temperature and the specifics of water, danios are also unpretentious. They prefer water with an acid-base balance of 6.0-8.0 pH, a hardness of 5.0-19.0, a temperature of 18-24 ° C, although in the wild nature the amplitude of temperatures for them is greater. Danio is better than overcooling than overheating. The minimum temperature to which water in their environment can fall is + 12 ° C. Like all zebrafish aquarium fish, they do not tolerate sharp changes in environmental conditions. These characteristics of them played on the love of experimental biologists to this genus of fish. Their research has played a huge role not only in recognizing new species, but also in studying the effects of medicine on the aquarium fish, the environment, flora and fauna of the aquarium. Embryological scientists began conducting danio breeding work by introducing the color mutation gene into fish. Gene caught on, so now the fish are bright red or green. It is also noted that over time, adult individuals become brighter. However, a scandal erupted over mutated fish in 2003, fueled by members of societies for the protection of animals, which ended with the danio rerio being banned from being imported into the European Union. As a result of "staining" the fish can no longer return to their natural habitat. The fact is that they cannot change the brightness depending on the lighting, which means that their bright color will surely attract a curious predator.
Danio easily get along not only with their own kind, but also with viviparous, as well as with labyrinth fish. Danios belong to one of the most favorite species of aquarium fish - their cheerful disposition, unpretentiousness in conditions and bright color cause admirers of aquarists.

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One of the distinguishing features of this fish is extraordinary mobility. Dodging well to dine well in any company of fish, they live long and rarely get sick.
Danio (lat. Danio) is a genus of small fish of the carp family. Some of them are widespread in the aquarium culture (Danio-rerio, Danio pink). Zebrafish is used in biology as a model object for research. Striped danios are an excellent model for studying the genetics and development of not only fish, but also all vertebrates, including humans. In the early 70s of the last century, a new laboratory model appeared in the arsenal of scientists - this is the fish Brachydanio rerio, or striped danios (in English-language literature known as "zebrafish"). This small striped fish belonging to the carp family (Cyprinidae), the natural range of zebrafish is extensive - Pakistan, India, Bangladesh, Nepal, Bhutan. But now the fish with the help of humans is successfully settled in countries with warm climates. Wild populations are found in the USA and Colombia. She is also known to lovers of aquarium fish all over the world as a very unpretentious pet.
Studying its genome and developing new research approaches allows scientists to make more and more new discoveries. Some articles: Biotechnology: Innovative Solutions in Cancer Therapy
Biotechnology:: Striped danios will help in cancer research
Want to change skin color - drink the pill
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It turned out that zebrafish could not be better suited for experiments with GFP and RFP transgenes and this is why: zebrafish or zebra danio (zebra fish), has long been used by scientists as a very convenient model object in Zebrafish English literature .
New studies have confirmed the toxicity of silver ions!