Reproductive period and recruitment of Penaeoidea shrimp on the southeastern Brazilian coast: implications for the closed season

The aim of this study was to assess whether all Penaeoidea shrimps captured by trawling are protected by the current closed season. We investigated the reproductive period and juvenile recruitment of Penaeoidea shrimp species captured in the bay-estuary complex of Santos and Sao Vicente from May 2008 to April 2010. Samples were collected monthly using a shrimp boat at four sites in the estuary and four sites in the bay; environmental factors were monitored. The reproductive condition of females was determined by macroscopic observation of gonads. Juvenile and adult males were classified by observing the endopod forming the petasma; the reproductive condition was determined by the presence of spermatophore in the terminal ampoule. A dendrogram showed little similarity in the reproductive periods of the species sampled in this study. The greatest similarity in the recruitment period was in the white shrimp, Litopenaeus schmitti , and the pink shrimps Farfantepenaeus paulensis and F. brasiliensis , species that are protected by the current closed season. Pink shrimps are not fully protected, however, as they are captured indiscriminately in the estuary, to be used as fishing bait. Considering the number of individuals of reproductive females and juveniles, Xiphopenaeus kroyeri was the most abundant in the marine environment, and L. schmitti , F. paulensis and F. brasiliensis were the most abundant in the estuarine environment. The adequacy of the closed season is discussed, including issues such as the implementation of projects focusing on fishermen and the sustainable use of bait; the closure of fishing from October to December in coastal areas with depths below 20 m, and the application of a regional closed season instead of the current law applied in several states.