Gonadal development, reproductive investment and fecundity of Aegla castro Schimitt, 1942 (Crustacea, Anomura)

Abstract

ABSTRACT Aegla castro, is an endemic anomuran crab from Brazil found in headwater streams of the Atlantic Forest on the Paranapanema River basin. This study aims to evaluate the gonadal maturity of A. castro based on macroscopic and microscopic analyses. Crabs were collected in Mauá da Serra (23º57’ S; 51º06ʹ W), Paraná, Brazil in the winter and spring of 2015, and summer, autumn, and spring of 2016. Individuals had their gonads analysed and categorized into stages of development. Stage1, ovaries are macroscopically undetectable through abdominal transparency, while ovaries of stages 2 and 3 could be detected through abdominal transparency and have characteristic colour and length in relation to the abdominal somites. Ovaries have pre-vitellogenic and vitellogenic oocytes in all stages of development, with germ cells and structural epithelium characteristic of these gonadal maturation phases. Spermatogenesis in males begins in spring, with the production of spermatozoa in autumn and spermiation in winter. Aegla castro has seasonal reproduction. The macroscopic stages of gonadal development correspond to the histological gonadal maturation, indicating that the macroscopic observation of the gonads of live animals is feasible in studies of the reproductive cycle of aeglids.