Fish Farming

2023 Author: Molly Page | [email protected]. Last modified: 2023-11-27 22:49

Preparatory work. For a correct understanding of the processes occurring during the reproduction of fish, let us recall some points concerning the reproductive system of fish. The vast majority of fish are dioecious, that is, there are males and there are females. In some species, cases of transformation of one sex into another are observed, as a rule, the female turns into a male.

The male genitals are paired testes, or milk, from which there are ducts ending in the genital opening or copulatory organ. During the breeding season, a male's milk contains a huge number of sperm - male germ cells. The female reproductive organs are paired ovaries or, in rare cases, one ovary, terminating in a short external duct with a genital opening. In the ovaries of the female, female reproductive cells (eggs) mature. The number of eggs depends on the type of fish, size and age. As a rule, the larger and older the fish, the more eggs it carries on its own.

Genetically modified fluorescent fish (GloFish® Tetra)

The structure of the egg is very complex. This tiny ball contains the program for the development of the future fish for its entire future life and the building material for the development of the larva. The double shell of the egg is represented by the outer sticky mucous membrane and the inner thick shell, which have holes through which spermatozoa penetrate into the eggs. After the fusion of the nucleus of the sperm with the nucleus of the egg, the embryo begins to develop. Development takes place at the expense of the yolk, part of which remains as a reserve material in the body of the larva, in the form of a tai called the yolk sac, which gradually dissolves. The end of the larval stage is the moment when the larva begins to feed on its own.

Fish are subdivided into viviparous and spawning. The majority of spawning species. Of the viviparous fish, the most popular are guppies, swordtails, mollies, plyatipecilia, girardinus, and formosa. These fish are easy to keep, diverse in color and shape, and, most importantly, produce live, fully formed fry. Their reproduction does not require special conditions and skills. Once fertilized, a female can give birth up to 8 times, each time producing tens and even hundreds of fry.

Fertilization of eggs in viviparous fish occurs inside the body of the female. The male's milk gets there through the male's anal fin, part of which is transformed by nature into a copulation tube - gonopodia. There are hooks on the outside of this tube. The shape of the hooks allows mating only with females of their own species.

Bearing offspring lasts from 18 to 62 days.

For breeding viviparous fish, you first need to select producers - a female and a male, the largest, correctly folded and brightly colored. Producers are planted in a separate container, planted with hornwort, ludwigia, pinnate, sagittaria, hygrophilia, kabomba. It should be remembered that adults are prone to cannibalism, so fry need to hide in dense vegetation.

After birth, the fry can be immediately fed with live dust and small cyclops, brine shrimp, micromin and egg yolk. It is advisable to plant the producers and fry in different containers. You can act according to another scheme - to transplant the producers and after fertilization, the female, immediately before giving birth, is placed in a spawning basket floating in the aquarium, which has slots or holes through which the fry can swim away into the main volume immediately after birth. This method excludes the extermination of its fry by the female.

As the fry grow, they begin to feed them with large cyclops, live daphnia, and small bloodworms. Sexual maturity occurs between two and ten months of age, depending on the species.

Angel bicolor, or centropyge blue-yellow (Centropyge bicolor)

There are many species of spawning fish … Reproduction requires special skills and knowledge. The main points that determine the success of breeding spawning fish are the correct pre-spawning preparation, temperature, composition and thickness of the water layer, the substrate on which the fish will lay eggs, the minimum required spawning grounds, the preferred breeding season, the amount of oxygen in the water, illumination, the general landscape of the spawning grounds., a sufficient number and a certain selection of plants, or, conversely, a complete absence of plants, the age of producers. These factors are different for each fish species. In addition, it also happens that everything seemed to be done correctly, but the fish do not start spawning. Some last impetus to the maturation of the reproductive products is missing. This impetus can be a change in the composition of the water, an increase in temperature, the presence of a second male,a pot, wide leaf or plant that has appeared in the spawning ground.

If soft, slightly acidic water is recommended for spawning of a certain type of fish, then it is better to keep the producers in hard, slightly alkaline water before spawning. A change in the qualitative composition of water is an impetus for them to spawn.

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All preparatory work culminates in the mating games of the producers … In most popular species, the female first begins to chase the male, then the roles change, and the male actively looks after the female. The end of mating games is spawning. The female lays eggs, the male fertilizes her with seminal fluid. Each species of fish has characteristic features of the spawning course, its speed, the amount of eggs laid, the behavior of the broodstock at the time of spawning and after it. It is very important to know the minimum spawning area and water level for each fish species. The very nature of mating games, the sequence of movements, the diameter of the described circles during the movement of the mating pair require a certain depth and size of the spawning ground. In the spawning ground itself, it is necessary to put, again depending on the type of fish, ceramic pots, broad-leaved plants, a couple of bundles of willow roots, previously boiled, a ball of thin nylon threador small plants floating near the surface of the water.

It is advisable to plant fish for spawning in the evening, arrange the aquarium so as to provide the required lighting. Some fish spawn when the morning sun appears, while others prefer shading. They treat their caviar and juveniles differently. Some devour their caviar, others do not touch, others show selfless care for their offspring. After spawning, the producers are immediately planted from the spawning grounds.