The different depths gradients may affect the reproductive dynamics of Hepatus pudibundus (Herbst, 1785) (Decapoda: Aethridae) in the southeastern region of Brazil

Abstract

The aim of this study was to evaluate the spatio-temporal variation and influence of environmental factors on the reproduction of H. pudibundus, and to estimate the size at the onset of sexual maturity (CW50). Samples were taken monthly from January to December 2000 in nine transects ranging from 2 to 40 m of depth. Bottom temperature, salinity, and sediment texture were recorded at each transect. Crabs were separated according to sex, measured (carapace width; CW), and classified according to their gonadal development stage. In total, 1808 individuals were captured: 498 males, 1039 non-ovigerous females, 173 ovigerous females, and 98 juveniles (males and females). The average size at the onset of sexual maturity of males and females was similar, 32.1 mm and 32.0 mm, respectively. This was unexpected since larger males have an advantage in competitions for females and during intraspecific interactions. Reproduction occurred continuously year-round, with peaks in summer and spring. These peaks might be caused by a higher food availability during this period, which could provide better survival conditions for the larvae. Reproductive females were more abundant at depths of 10–25 and 40 m, probably due to their migratory behavior that facilitates larvae dispersal and survival.