The reproductive cycle of the firetail gudgeon, Hypseleotris galii I. Seasonal histological changes in the ovary

Abstract

Seasonal histological changes in the ovary of H. galii are described. Oogenesis occurs in January and February, at the end of the breeding season. Evidence suggests that oogenesis continues in senile (post-reproductive) fish. Oocytes in the primary growth phase grow throughout the winter months. Vitellogenesis commences in August, and fish mature by November. During the breeding season (November-January) females ovulate and spawn repeatedly. Mature oocytes remaining after the breeding season become atretic. The fate of follicular derivatives and their possible role in steroid biosynthesis is discussed.