Reproduction and gonad histology of Aidablennius sphynx (Pisces: Blenniidae) of the Catalan Sea (northwestern Mediterranean)

The reproductive biology of the Mediterranean blenny fish Aidablennius sphynx was studied on the basis of microscopic and macroscopic analysis. A. sphynx is a resident species of the shallow waters of this region, lays demersal eggs and provides parental care to the developing embryos. Mature male gonads occur between March and July, whereas mature females appear between April and August. Male gonads are composed of the testis and the testicular gland. Spermatids are released into the testicular gland. The testicular gland is relatively more prominent than the testis after the reproductive season. Six stages of oocyte development (included atretic ones) are considered. Seasonal variations of gonads of both males and females are illustrated. Low fecundity was recorded, as the ovaries may contain432 to 1682 oocytes according to female size. Equations describing the relation ship, between gonad weight and length and weight of males and females are presented. Equations describing the relationship between absolute individual fecundity and length and weight of females are also presented.