A full-system study of neuroendocrine regulation of fish reproduction. 1. Development biotech management principles of artificial fish reproduction on the basis of the ecologo-histophysiological scientific approach

Abstract

A completed full-system (scientific-applied) ecological-histophysiological study of the hypothalamo-hypophysial neurosecretory system (HHNS) participation in fish reproduction was established. With the help of light-, electron-microscopy and immunocytochemistry it is established for the first time that at the beginning migrations of passing fish there is a mass accumulation of neurosecretory products in neurohypophysis, which indicates to the inhibition of the normal level of their excretion into the bloodstream. At the same time, they are actively synthesized in the pericarions of the neurosecretory cells in the preoptic nucleus and excretioned into the cavity of the III brain ventricle. Firstly it is a sign of a violation of their basic osmoregulatory function, which should cause a change in habitat. Secondly, the synchronous excretion of neurohormones into the brain’s liquor should cause their neurotropic effect on the CNS behavior centers in the form of a dominant state of arousal in the form of “migration impulse”. At the beginning of spawning, regardless of its season, HHNS also initiates spawning behavior and completes spawning by participating in the body’s protective-adaptive reactions to natural physiological stress. The functional role of the HHNS in fish reproduction is to initiate energy-intensive reproductive processes of migratory and spawning behaviors, and to complete spawning by suppressing the hyperactivity of the target glands, which ensures the body’s transition to energy-saving plastic exchange. The analysis of this key role of HHNS in the integration of fish reproduction by the principle of self-regulation has allowed to define the principles of effective reproduction and cultivation fish management, primarily in the form of finding the most effective impacts on the centers of integration of managed functions or modeling their effects, which should be carried out in natural periods of functional lability of the body. A constructive working scheme neuroendocrine integration of fish reproduction has been presented and the possibility of applying method of comparative analysis to further develop the system management biotechnics of fish populations reproduction is considered.