The reproductive cycle of the firetail gudgeon, Hypseleotris galii II. Seasonal histological changes in the testes

Abstract

Seasonal histological changes in the testis of H.galii are described. Spermatogenesis follows the cystic pattern common in anamniotes. Mitotic increase in spermatogonia occurs in late autumn, when photoperiod and water temperature are falling. The meiotic division of spermatocytes and subsequent changes of spermatogenesis are initiated when photoperiod and water temperature are rising and continue through the breeding season (November-January) until March, when water temperature begins to fall rapidly. The possible role of cholesterol-positive lobule boundary cells in steroid biosynthesis is discussed.