Morphological and physiological studies regarding gonadal differentiation and sex change in Serranidae

Abstract

Groupers in subfamily Epinephelinae, family Serranidae, are highly valuable marine resources, especially in Southeast Asia including Japan. The objective of this study was to understand the morphological characteristics and endocrine mechanisms underlying the sex differentiation and sex change in groupers. First, we analyzed the morphological characteristics and the role of sex steroid hormones on the gonadal sex differentiation using the large Malabar grouper, Epinephelus malabaricus. Next, the physiological mechanism of sex change was revealed by using the small Honeycomb grouper, E. merra, as a model fish. Finally, we succeeded in inducing an artificial sex reversal from female to male in the groupers by using aromatase inhibitor or gonadotropin; this is in addition to the alreaady-existing methods that use androgen and could be achieved by applying the basic information about the physiological mechanism of sex change in groupers.