Complex of Steroid Hormones in Invertebrate Hydrobionts

The presence of a complex of biologically active steroid compounds (BASCs)—hydrocortisone, corticosterone, progesterone, testosterone, and estrogens (vertebrate hormones)—in invertebrate hydrobionts of different phylogenetic levels has been revealed in experiments. The features of the quantitative content of BASCs in different organs/tissues of hydrobionts and their changes at different stages of development are shown. The level of BASCs in organisms or their organs is largely due to their own steroidogenesis, but organisms can accumulate exogenous steroid compounds. The adaptive role of BASCs in some invertebrates in changing conditions of the aquatic environment has been found. The similarity of the concentration of steroid compounds in different groups of bionts leads to the idea of a certain “physiological constant” of this complex of compounds in all organisms.