Biologia reprodutiva de Macrobrachium olfersii (Wiegman) (Crustacea, Decapoda, Palaemonidae) coletados na Ilha de Santa Catarina, Brasil Reproductive biology of Macrobrachium olfersii (Wiegman) (Crustacea, Decapoda, Palaemonidae) collected at Santa Catarina's Island, Brazil

<abstract language="eng">The aim of this study is to characterize the reproductive features of Macrobrachium olfersii (Wiegman, 1836) from Santa Catarina's lsland. The animals were collected in freshwater streams of the Ratones Hidrografic Basin (site A1) and at the Peri's Pond (site A2). In the laboratory, the procedures of sexual differentiation were carried out to classify the individuais in males, females or ovigerous females, followed by the determination of total weight (g), quelipod relative weight (g) and total length (mm). The eggs were removed from the ovigerous females and counted. Sexual maturity and fecundity were analyzed based in the dimensions and number of eggs carried by ovigerous females. The water temperature on the capture sites varied from 17 to 29ºC throughout the months of study. A total of 503 individuais were captured, with 129 individuais from site A1 and 374 from site A2. The mean total size and length was 49.65 mm and 3.79 g for the males, 38.75 mm and 1.61 g for the females and 36.19 mm and 1.08 g for the ovigerous females. At the sites A1 and A2, the individual sexual maturity was reached with 27.3 and 21.2 mm of total length, respectively, while populational sexual maturity was estimated for the 45.0 to 50.0 mm class at site A1 and for the 30.0 to 35.0 mm class at site A2. The ovigerous females carried an average of 3464 eggs at site A1, and 1440 eggs at site A2. These reproductive features, presented by M. olfersii, show the species' plasticity, which can be associated with environmental variations, contributing to its reproductive success