Biologia reprodutiva de Macrobrachium olfersii (Wiegman) (Crustacea, Decapoda, Palaemonidae) coletados na Ilha de Santa Catarina, Brasil

Abstract

Reproductive biology of Macrobrachium o({ersii (Wiegman) (Crusta- cea, Decapoda, Palaemonidae) collected at Santa Catarina's lsland, Brazil. The aim of this study is to characterize the reproductive features of Macrobrachium olfersii (Wiegman, 1836) from Santa Catarina's Island. The animaIs were collected in freshwater streams ofthe Ratones Hidrografic Basin (site A I) and at the Peri's Pond (site A2). In the laboratmy, the procedures of sexual differentiation were canied out to c1assify the individuaIs in males, females or ovigerous females, followed by the detennination oftotal weight (g), quelipod relative weight (g) and totallength (mm). The eggs were removed from the ovigerous females and counled. Sexual malurity and fecundity were analyzed based in the dimensions and number of eggs carried by ovigerous females. The water temperature on lhe capture sites varied from 17 to 29°C throughout lhe months of study. A total of 503 individuaIs were captured, wilh 129 individuaIs from site A I and 374 ll'om site A2. The mean total size and lenglh was 49.65 mm and 3.79 g for lhe males, 38.75 mm and 1.61 g for lhe females and 36.19 mm and 1.08 g for the ovigerous females. At the sites A I 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 c1ass at site AI and for the 30.0 to 35.0 mm class at site A2. The ovigerous females carried an average of 3464 eggs at site A I, and 1440 eggs at site A2. These reproduclive features, presented by M olfersii, show the species' plasticity, which can be associated with environmental variations, contributing to ils reproductive success.