Growth and mortality of Hepatus pudibundus (Crustacea: Calappidae) in south-western Brazil

Abstract

The predatory action of the pink shrimp (Farfantepenaeus brasiliensis and Farfantepenaeus paulensis) trawling fishery in south-western Brazil affects populations of some benthic species and Hepatus pudibundus is an abundant by-catch in this fishery. Individual growth and mortality of H. pudibundus were studied by taking monthly samples for a year from the by-catch of the pink shrimp fishery in the Ubatuba region. The von Bertalanffy growth model described growth of H. pudibundus (K=2.73 y-1, CW∞=82.97 mm; K=2.62 y-1, CW∞=66.72 mm, for males and females respectively). Modal progression of the monthly average sizes was related to increasing values of relative condition index. The instantaneous coefficients of total, natural, and fishing mortality were: males, Z=7.62 y-1; M=1.80 y-1; F=5.83 y-1; females, Z=7.36 y-1; M=1.80 y-1; F=5.56 y-1. Length composition and mortality analysis suggest that H. pudibundus in the Ubatuba region might be overfished.