Ovarian atresia in cephalopods

Abstract

Ovarian atresia is described for the first time in cephalopods. Detailed histological examination of ovaries of Loligo vulgaris reynaudii in various stages of maturity revealed atresia in primary, previtellogenic and vitellogenic oocytes. These were analysed separately. Previtellogenic and vitellogenic oocytes could be subdivided into five clear stages, whereas primary atretic oocytes are given a general description. Follicular atresia lowers the number of maturing and mature eggs in the ovary, so previous fecundity estimates for cephalopods may have been too high. To correct potential fecundity estimates for losses arising from atresia, it is necessary to estimate the duration of each atresia stage in relation to the total spawning period.