The present study describes the characteristics of female and male reproductive cells during gonadal development and the gonadal maturity scale of the Mediterranean green crab, Carcinus aestuarii. A total of 6283 specimens were collected from the Kndeniz Lagoon of Izmir Bay in the Aegean Sea. the gonads were removed and processed following the histologic standard tecniquc of hematoxylin and eosin staining. Gonad development stages previously determined were based on external and macroscopic morphology and afterwards each stage was microscopically described. C. aestuarii showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with seven developmental stages in females and six developmental stages in males. in the histological features, the ovary consists of lobes, and each lobe is divided into lobules. A thick capsule surrounds the ovarian lobule, which is composed of follicles, each containing a cluster of oocytes at different types. There were six types of oocytes; protoplasmic, previtellogenic, early vitellogenic, late vitellogenic, mature, atretic. the male reproductive system consisted of testis, vas deferens and an ejaculatory duct. the vas deferens was divided based on histology into three parts such as anterior, median and posterior.

This study was financially supported by the EBILTEM (Science and Technology Centre of Ege University) (Project No: 2014/SUF/016). We are indebted to thank both referees for their valuable and constructive comments.

EBILTEM (Science and Technology Centre of Ege University)Ege University [2014/SUF/016]

WOS: 000545742800001