The zebrafish, with the scientific name Brachydanio rerio, is a species native to the fresh waters of India and Pakistan. It has become a very popular fish due to its very easy care, making ideal for novice keepers.
Regarding the reproduction of zebrafish, there are some peculiarities that must be taken into consideration, not only so that they are born the fry, but also so that they grow strong and he althy. Keep reading this article on our site to discover everything about this species.
Before playback
Zebrafish are social animals, so having groups of adults of between 6 and 10 fish is ideal. When they do not belong to a school, these fish become violent, irritable and nervous, which is negative not only for their general he alth, but also for their reproduction. We recommend a large fish tank so they can swim freely.
Make sure your school has both male and female fish. Males tend to be slimmer, with a golden body crossed by bluish lines, while females have a bulkier belly with blue lines and a white body.
Your life expectancy, under optimal conditions, is 4 years maximum. They reach sexual maturity after 8 months, but some specimens can take up to 16 months before they can mate. They breed at any time of the year, so it's up to you to provide the ideal setting for this.
When you've decided it's time to breed, feed the fish in the school life food a couple of weeks before mating. Add to the tank or fish tank mosquito larvae, insects, daphnia and artemia This type of food will not only contribute to the he alth of the offspring, but also stimulates the mating process.
Zebrafish Mating
After two weeks of live food, choose the female with the most swollen abdomen, an indicator that she carries a large number of eggs, and two males that look active. If you want more offspring you can also mate a greater number of fish, always counting two males for each female.
It is necessary to set up a separate tank only for mating and breeding, because the adult fish devour the eggs and their own sons. Move the potential parents to this tank overnight and wait 24-48 hours for spawning to occur.
You will notice that at dawn the males will begin to chase the female, who will try to flee from them. This is completely normal in the mating ritual. When her female is tired, she will accept the male and expel the eggs, which will fall to the bottom of the tank, where they will be fertilized by the male. There will be between 200 and 400 eggs At the end of this process, return all the adults to the large tank with the rest of the school.
How should the breeding tank be?
Before mating and spawning, the fish tank for reproduction and breeding, smaller than that of the school, must be conditioned in a specific way.
Get a fish tank or aquarium of about 20 liters The water temperature should be 27 degrees Celsius. Zebrafish eggs don't stick on their own, so you'll need to find a way to keep them safe and secure. We offer you 3 options for this:
- Place marbles at the bottom of the tank to protect the eggs.
- Install a mesh net with fine holes about two inches from the bottom of the aquarium.
- Cover the floor of your fish tank with coarse gravel.
Any of these methods will serve to build a space in which the eggs can remain stationary and away from the parents at the exact moment of spawning. Apart from this, add a sponge filter with aeration, a thermostat to check the temperature and some floating plants This will create a suitable environment for the little ones to be born.
In addition, you must cover three of the sides of the aquarium to control the entrance of the sun, which must only hit them directly from the tomorrow, through the face that is uncovered.
During mating, the water in the tank should be very little, just enough to cover the method you have implemented to shelter the eggs, plus something extra for the parents to swim through. The idea is that the eggs fall as soon as possiblein a safe place, because the female devours them as she expels them
At the end of spawning and when you have removed the parents from the breeding tank, add more water and a few drops of methylene blue to prevent fungal growth.
Eclosion and youth
The eggs hatch on the third day of spawning. You will notice small transparent spots adhering to the crystals of the fish tank. During this stage it is not necessary to provide them with food, as they feed on their own yolk sac.
Between day 5 and 6 they will begin to venture around the tank on short trips and you will need to feed them powdered fry food and yolk of boiled egg in tiny dimensions, which you will offer them in small quantities so as not to dirty the tank unnecessarily. At this stage the aquarium continues to be covered.
As the fry grow, the water level is increased and they are offered more hours of light. For the essential water changes, only use the tube of your sponge filter, otherwise you will not be able to change it without affecting the fry. In order to optimize cleaning, you may also add some live snails to the tank, which will take care of ingesting the waste.
Soon, from day 10 or 12, you will be able to feed them with porridge prepared at home and artemia larvae. Mortality is very high, but after three months they will have reached adulthood. You can place them in the shoal tank, if the size of the shoal allows you to have so many specimens together. Otherwise, it is advisable to purchase another.
