Fry cockerel, development

A touching moment in the life of each aquarist watching the birth of a new life in the aquarium. The beauty of spawning a pair of cockerels is fascinating with its marriage dance. From the appearance of caviar in the nest to the complete development of fish in sexually mature specimens of cockerels - 3 months of waiting.

lineyka_rosta For a month and a half, the aquarist only wonders what kind of result he did. Was it possible to achieve the desired result of obtaining color variation and shape, how many males and females turned out in the brood, how many eggs this difficult period in development passed. Cock fish begin their lives with eggs fertilized during spawning up to 1 mm in diameter, in this stage the cock fish is on average 36 hours (largely depends on the temperature of the water). After two days, larvae appear in the nest. At first, it's just "tailed eggs." On the third day, the larva acquires a body shape that is already more reminiscent of a fish but with a large white belly, the so-called yolk pouch is the parent gift of a supply of nutrients for the first time. The supply of the yolk pouch is absorbed by the larva within 2-3 days.

Личинка петушка в 4 дневном возрасте

Cockerel larva at 4 days of age

At this time, the movement of the larvae is sharp and chaotic, they are in the nest or hang on the walls of the aquarium. When the supply of the yolk pouch ends, the larva can be safely called a fry.


Fry (larvae) cockerel at 6 days of age

At 6 days, the baby reaches a size of 2, 5-3 mm. Completely transparent with pronounced black eyes. Developing internal organs are visible through the transparent body of the fry. At this time, the first feed is introduced into the aquarium. It can be egg yolk, infusoria or starting dry feed for fry. Cockerel fry develop quite quickly and by two weeks of age reach a size of 5-6 mm.

At this stage of development, the fry has only caudal and pectoral fins. The first signs of the dorsal fin appear in the small one at the age of 21-22 days. The size of the fry at this age varies greatly, the fry develops at different rates and some of the fry become larger than others.

During this period of life, a small cockerel is fed with finely divided tubular, arterial nuplia, grated into fine dust with dry fodder. At the age of three weeks, some fry have the first scales in the area of ​ ​ the gill covers, through the still transparent body of the fry, the dark lines of the skeleton and internal organs are already clearly visible.

каннибализм  среди мальков

cannibalism among fry

When the fry have reached the age of three weeks, it is time to think about sorting the fry so that the larger ones do not start eating small brothers and sisters, and cannibalism among the fry is not uncommon.


little cockerel at the age of 1 month (begin to stain)

Periodically sorting cockerel fry can be grown in one aquarium almost until the age of mature. At the age of about one month and when the fry reach a size of 1 cm, the fry begins to rise to the surface of the water to capture air, which indicates the development of a labyrinth organ in the fry. From this moment, aeration in an aquarium with fry is no longer needed (except if aeration was used to mix water with the aquarium heater turned on).


young Betta Splendens (cockerel fish) in one aquarium

Once the grown cockerel boys have become full-fledged fish, they should be kept separate from their relatives, the deposition must be carried out at the first signs of aggression.