Gonadal maturation of the female smooth lumpsucker (Aptocyclus ventricosus)

Abstract

Features of oogenesis, ovarian maturity phases, and fecundity of the smooth lumpsucker (Ap-tocyclus ventricosus) are described here for the first time. Gonadal development was examined by histological methods and the morphological features and size of germ cells at various stages was determined. These features were used to more accurately define morphological criteria of 7 histological and macroscopic maturity phases. The smooth lumpsucker is an iteroparous gono-choristic species with determinate fecundity, group-synchronous ovary organization, total spawning (release of 1 batch of eggs per breeding sea-son), and external fertilization.