Population dynamics of the crab Hepatus pudibundus (Herbst, 1785) (Decapoda, Aethridae) on the southern coast of SAo Paulo state, Brazil

The present study investigated the population dynamics of Hepatus pudibundus in the Cananeia region, in southern SAo Paulo state, Brazil, focusing on population structure, growth parameters, longevity, sex ratio, reproduction and recruitment juvenile period. Sampling was performed monthly at seven stations from July 2012 to June 2014, using a shrimp fishing boat. A total of 1650 specimens were collected: 551 males and 1099 females. The males were larger than females. Reproductive females were captured throughout the study period and juveniles were captured in most months. Both of these demographic categories were positively correlated with temperature. Growth parameters showed differences between sexes: CW infinity = 78.91 mm, k = 0.0066 day(-1), t(0) = 0.0965 for males and CW infinity = 69.71 mm, k = 0.0053 day(-1), t(0) = -0.2404 for females. Longevity was estimated at 1.91 and 2.40 years for males and females, respectively. The findings provide a greater understanding of the life cycle in this species. Additionally, since trawl nets are not selective, this study also provides information for better trawl fishery management, addressing not only the target shrimp but also the by-catch species.