can fish change gender?

Fish that change sex is adapted to survive in conditions when it is difficult to meet a partner.  Cubs born of such an individual is completely identical with it in terms of the genetic code, since the fish fertilizes itself on its own, without the use of extraneous genetic materials. Let discuss can fish change gender and why do fish change gender.

can fish change gender 2

Why Do Fish Change Gender?

Underwater inhabitants change sex for a number of reasons:

Temperature conditions

In a number of species, it is not initially determined what sex the fry will be. Belonging is laid during the development of future fish from eggs, when most of the fry develop into males. This phenomenon occurs due to the work of the aromatase enzyme, which regulates the action of sex hormones. At high temperatures, the androgen-destroying substance becomes less active, which leads to an increase in the concentration of male hormones.


Has a similar effect. In aquarium conditions, due to a too bright lamp, the liquid heats up. Under optimal conditions, it is believed that more females appear capable of laying eggs to increase the population. If the external environment is unfavorable, the fry will experience stress, due to which androgens will prevail over female hormones.


In a number of coral fish, females can turn into males as they mature. A similar phenomenon is observed in parrotfish.

At birth, all individuals are female. First, they spawn several times, after which they find their own section of the reef. Then the structure of the reproductive system changes.

Living conditions

In schooling fish, the phenomenon is noted when an imbalance occurs. For example, clownfish live in groups, each of which consists of the main pair and the young males surrounding it.
When the main male dies, his place is taken by the strongest of the others. If the female dies, her partner will change sex. want to know about Do Fish Care For Their Young?

How do Can Fish Change Gender?

Scientists observed this process on the example of a group of females from which all males were evicted. RNA sequencing and epigenetic analysis were used to track the processes.

Due to the influence of unfavorable external factors (loss of the ability to reproduce), the fish begins to experience stress. The body begins to release hormones that destroy the reproductive system.

At the same time, substances begin to be produced, under the influence of which male genital organs are formed. At the same time, appearance and behavior change.

The gonad, the gonad of an individual, is completely rebuilt in the process of sex change. First, the genes responsible for the production of female sex hormones are turned off. Only after this are the systems that produce androgens activated.

what types of fish change gender

What types of fish change gender?

In addition to clowns and parrots, wrasse cleaners have the ability to change sex. They live in small groups from the main pair and the juveniles surrounding it. If the main male dies, the mate takes his place.

Seabass, pygmy angels, guppies, some species of sharks, representatives of the Aravan family are also capable of becoming a representative of the opposite sex. Scientists have found this ability in about 350-500 species.

Interesting Facts about Fish Change Gender

Blue-headed talasomas living in the Caribbean live in groups. The heads of the males of this species are blue. Because of this, they stand out against the background of the females living with them.

The male’s duty is to search for food, to protect females. This way of life is dangerous, so often the fish dies or is lost.

In a few minutes, the main female begins to look like a male, paints half of her body blue, takes on the responsibilities of the deceased. The ovaries turn into testes within 10 days.

Dorado fish change sex?

Dorado fish is not an aquarium fish, but it also changes sex during its life. Dorado This is a protandric hermaphrodite. Until 1-2 years old, the fish is male and after that it can spawn.

Guppies change sex?

Yes, they change and can even completely stop reproduction if the water density in the aquarium is high.

What kind of aquarium fish change sex?

Pecilia and guppies, swordtails, clownfish and parrot, wrasse (kobudai).

Which fish changes its sex in the 4th year?

Blue-headed talasoma (Thalassoma bifasciatum) changes sex after 4 years.

Leave a Comment