Chave ilustrada para identificação das zoés de Brachyura do estuário da Lagoa dos Patos (RS) e região costeira adjacente

The goal of this study is to provide an illustrated identification key to distinguish zoeal phase of Brachyuran larvae that occur in the estuarine and nearby coastal region of the Patos Lagoon. The key includes species, collected monthly, using a conical net (165 cm long, 60 cm mouth and 330 μm mesh). Sampling was carried out on surface and deep waters. The identification was based on specimens reared under laboratory conditions as well as from previous published studies. This key was constructed upon external morphological characters, easy to observe under a stereomicroscope and moreover, the presentation of figures allows a non-specialist to make identifications more easily.O objetivo do presente estudo é a elaboração de uma chave de identificação ilustrada das espécies de Brachyura que ocorrem no estuário da Lagoa dos Patos e sua região costeira adjacente. A chave abrange espécies as quais foram coletadas mensalmente, usando uma rede de plâncton (165 cm de comprimento, 60 cm de boca e 330 μm de malha). As amostragens foram realizadas na superfície e fundo. Os especimens foram identifcados mediante comparação com larvas cultivadas em laboratório e com descrições já existentes. A chave utiliza caracteres que não sofrem grandes transformações ao longo do desenvolvimento, e a utilização de figuras para ilustrar a chave permite a não especialistas facilmente identificar as espécies

Habitat selection of the pink shrimp farfantepenaeus paulensis and the blue crab callinectes sapidus in an estuary in southern Brazil: influence of salinity and submerged seagrass meadows

This study was conducted in two estuarine inlets (Saco da Mangueira and Saco do Arraial) at the Patos Lagoon estuary, southern Brazil. The changes in relative abundance and size of post-larvae and juvenile shrimp Farfantepenaeus paulensis and juvenile blue crab Callinectes sapidus were compared, considering the influence of salinity and the presence of submerged seagrass meadows. The analyses were performed using generalized linear models (GLM) for abundance variations and ANOVA for variations on the size of individuals. The pink shrimp was more abundant at Saco da Mangueira, in seagrass meadows and areas of higher salinity. The blue crab was more abundant at Saco do Arraial and in lower levels of salinity. The importance of submerged vegetation for the blue crab lies in a preference of smaller crabs of the species for the seagrass meadows. It has been shown that these species choose different habitats in the estuary, and both the salinity and the presence of submerged seagrass meadows influence the selection of habitat