© 1972 by The Society for Integrative and Comparative Biology
Hormonal Control of the Teleost Ovary
Institut für Allgememe Zoologie, Johannes Gutenberg University Mainz, Germany
The endocrine basis of gonadal development, reproductive processes, and many peculiarities related to reproduction in females of the highly diveisified teleosts can not yet be described satisfactorily. Although estrogens have been extracted from ovaries and peripheral blood of several species and various steroids were found to be produced by ovarian tissue in vitro, there is an almost complete lack of knowledge about their physiological role.
It is beyond any doubt that hormones of the pituitary have a marked influence on ovarian maturation but many problems await further clarification. It is not yet clear whether gonadotropic hormones might have a direct influence on certain traits of behavior in females. Biochemical work and a large number of histophysiological studies are at variance with regard to the question whether one or two gonadotropic hormones exist in teleosts. Technical difficulties (eg., shortage of hormonal material from various sources, species specificity of gonadotropic hormone (s), widely scattered data from a large array of species with considerable differences in reproductive biology) hamper comparative analysis, Investigations on the hypothalamic control of endocrine events are just in their beginning. The unique occurrence of ambisexual species in teleosts raises many questions which remain to be solved.