Danio fish belonging to the carp family have been familiar to aquarists for a long time. In the natural environment, they are found in almost all countries of South Asia.
In captivity, too, feel good, they are fairly easy to care for, no problem getting offspring. Below is a detailed instruction on breeding danios in an aquarium.
The ideal volume of aquarium for breeding danios is more than 10 liters, and the shape is preferable elongated, because the fish are very nimble and they need a lot of space for swimming. The optimal number of fish for simultaneous keeping is 7 or 8. It is a schooling fish, 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 liquid to clean.
Danio is almost omnivorous, the main thing is that the feed fraction should not be too large. If you plan to organize the breeding of fish in captivity, it is recommended to include in the diet of live food (daphnia, bloodworms, etc.).
Sexual maturity occurs between the ages of 5 and 8 months.
The most popular types of danios in Russia, which are bred at home:
- Roerio (zebra). Striped fishes of a blue-yellow coloring, in length no more than 70 mm. In 2003, they served as the basis for the development of a new species – danioglo with a fluorescent glow.
- Pink. Such danios can be freely kept in the general aquarium. The height of each individual – no more than 6 centimeters.
- Leopard. Size – no more than 5 centimeters. Body color is spotted, in accordance with the name.
- Orange flipper. This type of danios 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 species, reaching 10 centimeters in length.
Despite the external differences, according to the needs and behavior, all types are similar to each other, therefore the instruction for breeding danios in an aquarium can be called universal.
Danio fry are very similar to each other, it is almost impossible to distinguish them. But in adults, the differences are more obvious.
Males are smaller and slimmer. Females have a round belly. In addition, the males are colored brighter and have strong fins.
Females are noticeably paler.
If the female’s abdomen has swollen, then this means that she is ready for reproduction – she allocates pheromones to attract a potential partner. Males also secrete hormones that actively stimulate ovulation in “girls.”
This is carried out in the process of discharging homogenate and gonad from the seminal glands in water. Boys should be in the same tank with the girls for eight hours.
The zebrafish aquarium becomes mature at the age of five to eight months. By this time, females reach a length of 2.4-2.5 cm, and males – about 2.3 cm. Couples during the mating period are inseparable from each other and practically do not detach from the fertilization process.
The abdomen of females becomes noticeably more rounded.
The breeding season is not so important. Danio show themselves to be fruitful at any time of the year.
Much more important is the abundant and quality nutrition.
There are two options for spawning and storing caviar.
The first – in the general aquarium. It should be enough plants and different shelters, however, it is still high probability that the fish will eat most of their offspring.
The second is in the breeding ground. This is a separate aquarium of 20-40 liters, where at a distance of three centimeters from the bottom there is a special separator grid that fits snugly to the walls.
The delayed roe descends through the net, and there should be no gaps, otherwise adult individuals will be able to squeeze in there.
Sometimes, instead of a grid, spawning soil or balls with a diameter of a centimeter or more are used. If the eggs are lost among the balls / pebbles, it will be difficult for their parents to feast on them.
The instruction prescribes the first thing to separate pregnant females and males, by distributing them in different capacities. It is important to feed the fodder with high quality food, ask around at pet stores.
The best options – bloodworm, tube maker or daphnia.
As soon as the female’s abdomen becomes strongly round, it means that she is ready to spawn.
Desirable conditions for keeping spawning females:
- water temperature – depends on the season (in summer from +20 to +25, in winter from +17 to +22);
- the acidity of the liquid (pH) is from 6 to 7.5;
- water hardness – a maximum of 10 (to reduce the hardness level, you can dilute the liquid with distilled water).
Water needs to be enriched with oxygen, a vegetable substrate should be laid on the bottom (under the net), which includes: luster, peristristum, etc. After waiting for one or two weeks, the fish can be moved to the breeding grounds.
Permissible relocation in groups of 5 individuals.
It is comfortable for females to lay eggs in shelters, for example, from plants – such as long stem, such as mosses or ferns. The most suitable options: rogolisnik, Singapore moss, elodeus, Javanese moss, horned ceratopteris, winged fern.
The big belly of the female means complete readiness for throwing caviar. It is worth noting that danios are not viviparous fish, as many think.
Replanting fish that are ready for breeding should be carried out in the evening and with the lights turned off so as not to cause irreparable stress. If all is well, then spawn will begin in the morning.
In more rare cases, you need to wait another 1-2 days, and all this time not to feed the fish. If after two days the spawning has not started, it is permissible to throw a little feed and continue to wait.
If the result is still not there, you can plant the danios back into the general aquarium and repeat all of the above in a couple of weeks.
At first glance, throwing caviar looks as if the male is chasing a pregnant female through the reservoir. Nature has thought of everything – so he helps her to drop caviar. By the way, the water in the tank should not be much – enough level in 10 centimeters.
This is due to the fact that in nature the female is used to spawn in the very water column.
It is very important to pay a lot of attention to proper care of the caviar – the slightest infection or fungus will lead to its death. Generally accepted safety measures:
- Shade the tank.
- Add erythromycin to the liquid (to do this, grind the drug to a state of powder).
- Instead of erythromycin, iodine can be used for disinfection (three drops per ten liters of water).
- Some eggs may start to turn white 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 others do not have time to become infected.
In addition, you need to change every day part of the water in the tank with danio caviar (from 10 to 25 percent of the volume). Pure liquid should not be different in temperature from the old one.
When the larvae finally crawl out of the eggs, the first few days will just sit motionless on any surfaces that they only find in the aquarium. The larvae have a so-called yolk sac – it feeds them for the first time. After 5-6 days, this bag is absorbed, and the fish become more active – looking for food.
Now they can be called a fry with a clear conscience.
At first, the fry need to be fed with liquid food – special formulations are sold in pet stores. The basis of the diet are ciliates, and the finished food is the only addition to them.
It usually contains small crustaceans or plankton.
Fry grow extremely fast, soon they will reach a length of 15 mm – a sign that you can move them into a common reservoir. After six weeks, their approximate height will be 24 mm.
When one or a week and a half has passed after the first spawn, it is important to repeat the procedure again. If it is thoughtless to treat this, then the caviar will ripen, lose its life-giving properties, and fry will not appear from it. It also happens 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 a series of five or six eggs.
It is easiest to learn that the caviar is overripe (or, on the contrary, has not yet ripened), according to the behavior of the “danio” girl. After moving to the breeding ground, she behaves restlessly and constantly hides from the male in shelters and plants.
If the female is pregnant, but does not want to independently postpone her calf, then it is important to help her in a timely manner.
If the female’s stomach is very round and obviously full of caviar, then she still does not want to spawn, then you need to help her reset the over-ripe eggs. It is done this way: the fish is carefully wrapped in wet cotton and firmly held with two fingers of the left hand.
Then, with the index finger of the right hand, the eggs are 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 again for spawning.
Check out some of the nuances for successful breeding of various species of zebrafish:
- Pink danios for spawning necessarily need a separate aquarium. In addition, it is necessary to take into account the fact that for breeding one female of a pink zebrafish, you need two males at once.
- The spawning of leopard danios lasts for two whole months, and the most interesting thing is that during all this time a pair of fish remain faithful to each other.
- The situation with gold danios is similar, and they can save their pair not only for the spawning period, but also for the rest of their lives.
Finally, I want to give a couple of useful tips: if the fish suddenly, unexpectedly for you, began to spawn in the general aquarium, it is not too late to immediately plant them in a separate tank, so there is less chance that adults will eat caviar. The imitation of rain works well (adding cool water to an aquarium), in such “weather” danios breed much easier and more actively.
Do not be upset if the dilution is not set the first time. Zebrafish are not cars, but living creatures, so not everything goes according to plan.