Based on recent surveys of the freshwater decapod fauna, distributional data of five exotic species of freshwater decapod crustaceans for the hydrographic basins of the state of Sa˜o Paulo are presented, as part of a large initiative for a comprehensive survey of the state's biodiversity (BIOTA-FAPESP Program). These species are the North American crayfish Procambarus clarkii (Girard) (Cambaridae), the crab Dilocarcinus pagei Stimpson (Trichodactylidae) from the Amazon and Paraguay/lower Parana´River Basins, and the palaemonid shrimps Macrobrachium rosenbergii (De Man), from the Indo-Pacific region, Macrobrachium amazonicum (Heller) and Macrobrachium jelskii (Miers), both from the Orinoco, Amazon and the Paraguay/lower ParanaŔ iver Basins. Possible modes by which their introduction might have occurred are commented upon and potential consequences are discussed.

No abstract

No abstract

Este trabalho contribui para o conhecimento da riqueza de espécies de crustáceos decápodes do vale do Ribeira de Iguape, região sul do estado de São Paulo. Foram realizadas amostragens em seis Parques Estaduais (Campina do Encantado, Intervales, PETAR, Carlos Botelho, Jacupiranga e Ilha do Cardoso) e na Estação Ecológica Juréia-Itatins, abrangendo grande parte do remanescente de Mata Atlântica da região da bacia do rio Ribeira de Iguape. As coletas foram realizadas sazonalmente durante os anos 2000 e 2001, empregando dois métodos de amostragem (peneira e armadilha com isca). Foram registradas 18 espécies de crustáceos decápodes: Palaemonidae (6), Atyidae (3), Aeglidae (5), Trichodactylidae (3) e Grapsidae (1).

No abstract

No abstract

No abstract

The heterochelous condition of the second pair of pereiopods in both male and female Macrobrachium olfersi from São Sebastião, Brazil, was investigated by means of quantitative analysis. A positive allometric growth of the propodus (length and height) was observed for males and females, either juveniles or adults. The differential growth of both minor and major propodus is already initiated in the juvenile stage and proceeds towards adulthood without a distinct critical moult, and nally takes its full development in large adults, being especially more pronounced in large males. The differential growth of the larger second claw eventually leads to the development of the well known sexual dimorphism that characterizes this species. No preferential handedness, i.e., left or right, was discernible in either sex. RÉSUMÉLa condition d'hétérochélie de la seconde paire de péréiopodes chez le mâle et la femelle de Macrobrachium olfersi de São Sebastião, Brésil, a été étudiée par analyse quantitative. Une croissance allométrique positive du propode (longueur et hauteur) a été observée chez les mâles et chez les femelles aussi bien jeunes qu'adultes. La croissance différentielle, à la fois des petits et grands propodes commence déjà au stade juvénile et se poursuit jusqu'au stade adulte sans mue critique distincte et prend son plein développement chez les adultes de grande taille, et de façon plus prononcé chez les grands mâles. La croissance différentielle de la plus grande des secondes pinces conduit nalement au développement du dimorphisme sexuel bien connu qui caractérise cette espèce. Quel que soit le sexe, on ne peut discerner ni droitier, ni gaucher chez les individus.