Danio fish belonging to the cyprinid family have been familiar to aquarists for a long time. In the natural environment, they are found in almost all states of South Asia. In captivity, they also feel good, it’s easy enough to look after them, and without problems it is possible to get offspring. Below you will find detailed instructions for breeding zebrafish in the aquarium.
Features and varieties
The ideal volume of the aquarium for breeding zebrafish is more than 10 liters, and the shape is preferable elongated, because the fish are very quick and they need a lot of space for swimming. The optimal number of fish for simultaneous keeping is 7 or 8. The fish are schooling, and so it will be as comfortable as possible. It is important that there is always fresh water in the aquarium. Experts advise every week to replace 15% of the fluid with a clean one.
Danio is almost an omnivorous fish, the main thing is that the feed fraction is not too large. If you plan to organize the reproduction of fish in captivity, it is recommended to include live food (daphnia, bloodworms, etc.) in the diet. Puberty occurs at the age of 5 to 8 months.
The most popular types of zebrafish in Russia, which are bred at home:
- Rerio (zebra). Striped blue-yellow fish, no more than 70 mm long. In 2003, they served as the basis for the breeding of a new species - zebrafish glo with fluorescent glow.
- Pink. Such zebrafish can be freely kept in a common aquarium. The growth of each individual is not more than 6 centimeters.
- Leopard. Size - no more than 5 centimeters. The color of the body is spotty, in accordance with the name.
- Orange-fin. This kind of zebrafish has beautiful yellowish-orange fins.
- Hopra or firefly. The smallest subspecies, the length of each fish is less than 30 mm.
- Dangila. One of the largest varieties, reaching 10 centimeters in length.
Despite external differences, according to needs and behavior, all species are similar to each other, so the instructions for breeding zebrafish in the aquarium can be called universal.
How to find the difference between male and female?
The zebrafish fry are very similar to each other, it is almost impossible to distinguish between them. But in adults, the differences are more obvious. Males are smaller and slimmer. Females have a round abdomen. In addition, males are colored brighter and have strong fins. Females are noticeably paler.
If the female’s abdomen is swollen, it means that it is ready for reproduction - it releases pheromones to attract a potential partner. Males also secrete hormones that actively stimulate ovulation in “girls”. This is carried out in the process of dumping homogenate and gonads from the seminal glands in water. Boys should be in the same tank with the girls for eight hours.
How to identify readiness for breeding?
The zebrafish aquarium becomes sexually mature between the ages of five and eight months. By this moment, females reach a length of 2.4-2.5 cm, and males - about 2.3 cm. Vapors during the mating period are inseparable from each other and practically do not break away from the fertilization process. The abdomen of females becomes noticeably more rounded.
Season in the issue of reproduction is not so important. Danios show themselves fruitful at any time of the year. Abundant and high-quality nutrition is much more important.
Where to spawn?
There are two options for spawning and caviar storage.
The first is in a common aquarium. It should have enough plants and various shelters, however, the probability is still high that the fish will eat most of their offspring.
The second is in spawning grounds. This is a separate aquarium for 20-40 liters, where at a distance of three centimeters from the bottom there is a special separator mesh that fits snugly against the walls. The laid eggs fall through the net, and there should be no gaps, otherwise adults will be able to squeeze there.
Sometimes instead of a grid, spawning soil or balls with a diameter of a centimeter or more are used. If the eggs get lost among the balls / pebbles, it will be difficult for parents to feast on them.
Danio Spawning Tips
The instruction instructs the first thing to separate pregnant females and males, distributing them across different containers. It is important to feed the fish with high quality food, ask around at pet stores. The best options are bloodworms, pipeworms or daphnia.
As soon as the female’s abdomen becomes very round, it means that she is ready to spawn.
Desirable conditions for the maintenance of spawning females:
- water temperature - depends on the season (in summer from +20 to +25, in winter from +17 to +22),
- fluid acidity (pH) - from 6 to 7.5,
- water hardness - maximum 10 (to reduce the level of hardness, you can dilute the liquid with distilled water).
It is necessary to enrich the water with oxygen, to lay on the bottom (under the net) a vegetative substrate, which includes: glabella, cirrus leaf, etc. After waiting for one or two weeks, the fish can be moved to the spawning ground. It is permissible to relocate groups of 5 individuals.
It is comfortable for females to lay eggs in shelters, for example, from plants - such as long-stemmed ones, such as mosses or ferns. The most suitable options: hornwort, Singapore moss, Elodea, Javanese moss, horned ceratopteris, pterygoid fern.
Zebrafish spawning process
A big belly in a female means a complete readiness for throwing eggs. It is worth noting that zebrafish is not a viviparous fish, as many people think.
The transplantation of fish ready for breeding should be carried out in the evening and with the lights off, so as not to cause irreparable stress to them. If all is well, then spawning will begin in the morning. In more rare cases, you need to wait another 1-2 days, and all this time do not feed the fish. If after two days the throwing of eggs did not start, it is permissible to throw a little food and continue to wait.
If there is still no result, you can put the zebrafish back into the general aquarium and repeat all of the above after a couple of weeks.
At first glance, throwing eggs looks like a male chasing a pregnant female through a reservoir. Nature has thought of everything - in this way he helps her to discard her eggs. By the way, there should not be much water in the tank - a level of 10 centimeters is enough. This is due to the fact that in nature the female is used to spawning in the very thickness of the water.
How to care for zebrafish caviar
It is very important to pay a lot of attention to the proper care of caviar - the slightest infection or fungus will lead to its death. Common safety measures:
- Shade the tank.
- Add erythromycin to the liquid (to do this, grind the medicine to a powder).
- Instead of erythromycin, iodine can be used for disinfection (three drops per ten liters of water).
- Some eggs may begin to whiten a couple of hours after spawning. This means that they are infected with a fungus. You should immediately remove them from the aquarium with tweezers so that the rest do not have time to become infected.
In addition, you need to change part of the water in the tank with zebrafish caviar every day (from 10 to 25 percent of the volume). Pure liquid should not differ in temperature from the old one.
How to care for Danio fry
When the larvae finally crawl out of the eggs, the first few days will simply sit motionless on any surface that they find in the aquarium. The larvae have a so-called yolk sac - it feeds them the first time. After 5-6 days, this bag dissolves, and the fish become more active - they are looking for food. Now they can be called fry with a clear conscience.
At first, the fry must be fed with liquid food - special formulations are sold in pet stores. The basis of the diet is ciliates, and the finished feed is the only way to complement them. Usually it consists of small crustaceans or plankton.
The fry grow extremely fast, soon they will reach a length of 15 mm - this is a sign that you can transfer them to a common tank. After six weeks, their approximate growth will be 24 mm.
Danio spawning repetition
When one or a half weeks pass after the first hiccup, it is important to repeat the procedure again. If you take this lightly, then the caviar will become overripe, lose its life-giving properties, and fry will not appear from it. There is such a situation that the female does not want to throw overripe eggs at all, which is fraught with harm to her health. In nature, each zebrafish produces five to six spawners in a row.
To find out that the caviar is overripe (or, on the contrary, has not yet ripened) is easiest by the behavior of the “girl” zebrafish. After moving to the spawning grounds, she behaves uneasily and constantly hides from the male in shelters and plants.
If the female is pregnant, but does not want to lay eggs on her own, then it is important to help her in a timely manner.
If the female’s belly is strongly rounded and obviously full of caviar, then she still does not want to spawn, then it is necessary to help her lose the overripe eggs. This is done as follows: carefully wrap the fish in wet cotton wool and hold it firmly with two fingers of the left hand. Then, with the index finger of the right hand, caviar is squeezed out of it. If the procedure is carried out correctly and the zebrafish has not suffered, that in a week it will be ready for spawning again.
Is there a difference in breeding between zebrafish?
Check out some of the nuances for successfully breeding different types of zebrafish:
- Pink danios for spawning necessarily need a separate aquarium. In addition, one should take into account the fact that for breeding one female pink zebrafish you need two males at once.
- Spawning of a leopard zebrafish lasts for two whole months, and the most interesting thing is that during all this time a pair of fish remains faithful to each other.
- With gold zebrafish the situation is similar, and they can save their pair not only for the spawning period, but for the rest of their lives.
In the end, I want to give a couple of useful tips: if the fish suddenly, unexpectedly for you, began to spawn in a common aquarium, it is not too late to immediately drop them into a separate tank, so there is less chance that adults will enjoy caviar. Imitation of rain works well (adding cool water to the aquarium), in such “weather” zebrafish reproduce much easier and more actively.
Do not be upset if the breeding did not ask the first time. The zebrafish are not cars, but living things, so not always everything goes according to plan.
Danio Step-By-Step Guide
Step # 1: Switching to High Protein Products
Key to breeding Danio is diet. The fish evolved a simple biological mechanism - if there is a lot of food around, then you need to multiply.
Transfer the fish to a diet that consists entirely of live or frozen daphnia, bloodworms, mosquito larvae, and similar foods. During the week of such a diet, some of the fish will noticeably round up - these will be females filled with caviar.
Stage No. 2. Separation of males and females
Males and females in separate tanks
When it becomes clear where the females are, and where the males are, they are temporarily separated by placing them in two separate tanks filled with water from the main aquarium. The tanks are equipped with a heater and an air lift filter, and a lamp is installed outside. As the latter, it is permissible to use a conventional table lamp, which will become a light source for two tanks at once. Registration is optional.
Separate maintenance lasts about a week (7-10 days). All this time, the fish need to continue to feed live food and do not forget to remove the waste so that the water does not deteriorate.
Danio Crank Feeding
If it is not difficult for you to determine the sex of the fish and you already know where the males are and where are the females, then you can skip stage number 1 and immediately make a separation. In this case, the separate content lasts about 2 weeks. The diet is similar - with a high protein content.
It is worth noting that experienced aquarists do not share fish, but immediately place them in a spawning aquarium (about it below). However, beginners can miss the right moment of relocation, and Danio spawn in a common aquarium. In this case, saving the eggs will be problematic. Therefore, the separation option, although more troublesome, but allows you to control the reproduction process.
Stage No. 3. Preparation of a spawning aquarium
While Danio are in separate tanks, it's time to prepare a spawning aquarium. It can be almost any tank from a three-liter can to a basin. A volume of 20–40 liters is enough for a group of a couple of dozen fish.
Preparation of the spawning aquarium
Instead of soil, a layer of round balls (ceramic, glass) with a diameter of 1 cm, or large pebbles of the same size, a special artificial spawning substrate, or clusters of aquatic plants, such as Java moss, Vesicularia Dubi, and others, are placed at the bottom. The task of such a substrate is to protect the eggs from eating. Having fallen into the space between stones, sprouts / leaves of plants, they become inaccessible to adult fish.
The spawning aquarium is partially filled with water from the main aquarium, which is then mixed with fresh soft water with neutral pH values in a ratio of 50% to 50%. The recommended height of the water column is not more than 10 cm. The water temperature should be 2-3 degrees lower than in tanks with fish. The set temperature is maintained with the help of a heater - at this stage this is the only equipment of the spawning aquarium.
Stage number 4. Spawning (breeding) Danio
7-10 days after separation, the fish reunite again, but already in the spawning aquarium.
The union of males and females Danio
Usually, spawning occurs within 24 hours, the active phase occurs closer to dawn, when the dim morning light begins to penetrate into the room. During spawning, males make light bumps on the abdomen of females, which causes them to spawn. If males are not enough, females will not be able to get rid of eggs.
In the morning, carefully examine the substrate for the presence of small gray eggs. There are times when the fish fail to give offspring on the first day, so they are left in the spawning aquarium for another day. If nothing happened on the second day, the fish are again divided into separate tanks and fed with high-protein food for days. Then once again connect together.
Stage number 5. The final stage - the migration of adults Danio
Danios move to a common aquarium
At the end of spawning, the fish are returned back to the general aquarium. Reservoirs where males and females were previously kept empty, equipment is removed and put into storage.
Next, it is necessary to ensure the safety of eggs and future offspring, which is described in detail in a separate article.
Information in the "Fish" section regarding scientific names and living conditions
complies with FishBase materials - a global catalog of fish species,
coordinated by the Leibniz Institute of Marine Sciences.
Puberty and differences between male and female
It is possible to distinguish zebrafish by sex only in adults, since at a young age they are very similar to each other. You should look at all the fish and compare the sizes - males have a slender body, they are slightly smaller in size. Females are larger in their rounded abdomen. Danio can also be distinguished by color - it is paler in females, zebrafish boys have a brighter strip and developed fins.
Hormones secreted by males actively influence ovulation of females. This happens in the process of males dropping gonad fractions and testis homogenate into the water, which causes the appearance of ovulation in females. Boy fish must be present in the aquarium for 8 hours.
How to understand that it’s time to propagate?
Danios reach puberty by 5-8 months. Males are ready for mating in length about 23 mm, females - 24-25 mm.
Danio pairs stay together and mate continuously. The abdomen in females is rounded.
It is possible to breed Danio fish at home all year round. The breeding season is affected not only by the season, but also by plentiful nutrition.
Preparing for Spawning: Tips for Beginners
Firstly, it is necessary to separate the females and males in different aquariums. Feed the fish high-quality food - it can be daphnia, tubule and bloodworm. Look for good food at the pet store.
Before spawning for fish, it is advisable to prepare a separate tank or aquarium. The best parameters for water in the aquarium are the following:
- temperature depending on the season: in winter 17-21 ° С, in summer 20-25 ° С,
- acidity 6-7.5,
- hardness not more than 10 (in order to reduce the hardness of water add distilled water).
Pour water from a common aquarium into a new tank - about 10-12 liters. It should be in the range of 20-24ºС. Water must be enriched with oxygen. At the bottom, a fine-mesh, separator mesh is mounted at a distance of 5-10 cm from the bottom to preserve the eggs, a plant substrate is placed under it: pinnacle, glitter, etc. After 1 or 2 weeks, move the fish to the aquarium for spawning. They can be taken at once from a few from 5 or more.
How spawning goes: the whole process from a to z
The fish is launched into a new aquarium in the evening, when it is clear that the female’s abdomen has rounded. Most likely at dawn breeding will begin. Fish mate for several hours.
But how does zebrafish spawn? Брачный период у данио довольно интересен, они устраивают настоящие любовные игры: беременная самка носится по аквариуму, самцы плавают догоняя ее, стараясь ударить по брюшку хвостом. Тем самым они помогают ей избавляться от икринок.
Этот процесс идет неустанно пока у самочки не кончится икра. За это время одна самочка может отложить 100-200 икринок. Как только икринки попадут в воду самец оплодотворяет их. Они опускаются на дно проходя сквозь сетку. По завершении нереста производителей отсаживают в общий аквариум. After a few days (from 3 to 5) fry are born.
Care for caviar at home
To save the caviar, to prevent its infection with the fungus, the aquarium is shaded. Erythromycin (one tablet ground into powder) is added to water or water is disinfected with 2% iodine at the rate of 3 drops per 10 liters of water.
If the eggs begin to whiten 2-3 hours after spawning, this is a sign of a harmful fungus. To prevent diseases of the remaining eggs, remove the patients with tweezers.
It is necessary to change from 10 to 25% of the water of the container with eggs daily, adding pure water of the same temperature as in the aquarium.
For several days after hatching, the larvae sit motionless on everything in the aquarium. At this time, they feed on the yolk sac. After five or six days, it resolves and the fish are forced to start moving in search of food. From this moment they are already turning into fry.
How to feed the fry in the early days?
The first time the fry are fed with liquid foodthat is sold at pet stores. It is necessary to feed the babies first with ciliates, periodically adding ready-made feed - this can be plankton or small crustaceans. The fry grow very quickly. Once they reach a length of about 1.5 cm, you can move them into a common aquarium. After about six weeks, they will grow to 2.4 cm.
Does breeding differ according to zebrafish?
- Pink danios spawn better in a separate aquarium. To breed pink zebrafish, two males per one female.
- Breeding leopard zebrafish is characterized by the unique property of females to remain faithful to their partner throughout the spawning period, lasting up to two months.
- Golden zebrafish as well as leopard ones form a pair before spawning, often it remains for life. When the steam is in the spawning tank, you can add a little cool water to it, simulating rain, this will provoke spawning of fish.
Must spawn again in a weekotherwise, the caviar will mature and the fry will not appear from it. In situations when the female begins to hide from the male in the thickets of plants, this means that her calf is overripe or not ripened.
If the female’s abdomen looks complete and she refuses to spawn, she should be helped to get rid of overripe caviar.
Watch the zebrafish breeding video:
With the appearance of zebrafish in the aquarium fish house, be sure that a smile will appear on the face of everyone who sees bright, colorful fish. Daniushki scurry around the aquarium in a swift flock. It is impossible not to fall in love with these fish for their cheerful and restless character.