How to distinguish a female zebrafish from a male?

Danio rerio is one of the most popular aquarium fish, notable for its original color, agility and agility. This graceful and graceful creature has a peaceful and accommodating character, does not show aggression towards other inhabitants of the aquarium. When planning to start breeding zebrafish, you should first of all learn to distinguish females from males.

Danio rerio is a type of ray-finned fish that is small in size. The average body length of adults varies from 2.5 to 4 centimeters. Typical color is iridescent light silver with turquoise blue longitudinal stripes. The main difficulty in determining the sex of these fish lies in the strong similarity between females and males.

Another type of fish that is popular with aquarists is pink zebrafish... The colors of these attractive creatures can change under the influence of various factors. In some cases, the fish look deep pink, in others - silvery pink with a metallic sheen. In juveniles, a bright red stripe with bluish edges runs along the body, which becomes paler with age and soon disappears. As is the case with common zebrafish, it is quite difficult to determine the sex of pink fish due to their almost complete identity.

However, there are a number of specific parameters and differences that can tell an inexperienced aquarist the gender of a particular fish. It should be noted that sex can only be determined in adults, since in young zebrafish, gender characteristics are almost invisible.

The size of the individual can tell the gender of the zebrafish. Adult females are always slightly larger than males. Their abdomen is more rounded and large, and the belly line is slightly curved downward. This feature is associated with the main natural function of females, which is to reproduce the genus. For a female to bear offspring, her abdomen must be elastic and stretchable.

However, here it should be borne in mind that in male zebrafish, in certain cases, the abdomen may be slightly enlarged. This phenomenon is observed in diseases of the digestive system and malnutrition. In sick fish, the abdomen is more swollen in the front of the body.

Visually, zebrafish boys and girls are very similar. However, a detailed examination of each individual can reveal insignificant differences in their color. Males have a brighter color with a pronounced shine. The stripes on their body are deep turquoise in color. Males of pink danios are also noticeably more colorful than females. This feature is due to the fact that the bright color helps males to attract individuals of the opposite sex.

Zebrafish females, in turn, have a paler coloration.... Their stripes on the body are less pronounced and less colored. This feature can be easily explained: during gestation and subsequent spawning, fish need to mask themselves from predators.

You can also distinguish a zebrafish boy from a girl by their behavior. Having carefully observed their pets, it is easy to notice that some of them are more active, more energetic and agile, while others prefer a somewhat measured pace of life.

If the fish behaves very playfully, then with a high degree of probability we can say that this is a male. Zebrafish boys are always more active than girls. They show the greatest mobility during the breeding season. Their vigor and high speed provide them with leadership over competitors fighting for the female's attention.

This method is suitable for the experienced professional zebrafish hobbyist. However, it can also be used by very attentive beginners.

The shape of the anal fin in females is more rounded. In size, this part of the body is also slightly larger than that of males.

A rather simple experiment based on creating favorable conditions for reproduction will help to distinguish in practice between boys and girls of the zebrafish. In their natural habitat, these fish begin to breed during the period of heavy torrential rains. At this time, the temperature rises in the reservoirs and the water level rises, which creates the most suitable conditions for spawning.

At home, you can artificially recreate such conditions by stimulating adults to reproduce. For this, the water in the aquarium with fish should be increased to 24 ° and maintained at this level during the mating season. Fish at this time should be given live food: bloodworms, cyclops, tubifex, daphnia.

Warm water will encourage the fish to mate, during which it will be easy to find out the sex of a particular individual. So, after a few days, males will begin to show noticeable activity, huddling in flocks and chasing females.

During mating games, zebrafish females will be easy to distinguish by their enlarged abdomen in the anal fin area. At the same time, the color of the males will change: it will become even more saturated and bright. Such changes indicate that fish of both sexes are ready for reproduction and subsequent spawning.

If zebrafish are kept in a common aquarium with other inhabitants, then for the above experiment they should be deposited in a separate tank. The volume of the container should be 10–20 liters. The spawning grounds should be filled only with settled water.

For reproduction, 1 female and 2 males are enough. Usually the process of mating games does not exceed a few days. At this time, you should carefully observe the behavior of the fish. As soon as eggs appear at the bottom of the tank, the males and the female should be transplanted back into the general aquarium. The caviar is left in a jar for ripening. Later, fry will be born from the eggs, which are grown until they acquire the desired size. During this time, the young are fed with ciliates, rotifers or brine shrimp. When the kids grow up, they are transplanted into a common aquarium.

For sex differences in zebrafish and preparation for breeding, see below.