Endocrinological basis of adaptations related to ecology in fishes

Abstract

This paper gives the results of the analysis of the functional mechanisms of various hereditary adaptations that determine the mode of life of a species. An important role in the realization of many adaptations connected with the ecology of fishes belongs to the neuroendocrine system, as has been shown in a number of examples. Data have been obtained concerning the functional determination of the migratory behavior of fishes of different ecological and genetic groups. An undoubted causal dependence in adaptations connected with the process of reproduction of fishes (portional or total spawning, change in the season of spawning, atresia and resorption of oocytes during changes in the conditions of reproduction, etc.) upon the peculiarities of the function of the neuroendocrine system have been demonstrated. The leading role of neurohormonal regulation has been determined on the basis of the study of the adaptive radiation as a limit of species and population, which is of importance in the process of microevolution. Results of the work demonstrate the possibility and importance of investigation of the structure and function of the endocrine glands by analyzing concrete phenomena and functional mechanisms of adaptive evolution.