From the Greek hypóphysis a spur.

Pituitary injections are a method of stimulating fish reproduction (developed by Herbilsky) by injecting with a syringe into the fish body a suspension of pituitary gland, whose hormones control the production of sex hormones. The hormones do not stimulate the maturation of the gonads, but only the beginning of ovulation. For pituitary injections, pituitary glands of carp or bream or those of their own species or belonging to the same family, harvested from sexually mature fish whose gonads are in the last stage of development, are usually used. Chemical substances are also used.

The physiological method or hypophysial injection method is used for most spring and summer spawning fish (sturgeon, carp, bream, pikeperch, white amur, etc.). This method is also suitable for breeding aquarium fish.

The same gonadotropic hormone contained in the pituitary gland is used to stimulate the maturation of fish producers, and during spawning under natural conditions it enters the bloodstream from the pituitary gland, causing the maturation of germ cells. Gonadotropic hormone can accumulate in the pituitary gland of fish during certain seasons of the year (before spawning). This makes it possible to use the pituitary gland of donor fish as a source of gonadotropic hormone by which mature sex products can be obtained from producers at fish farms.