Dinâmica populacional de Aegla platensis Schmitt (Crustácea, Decapoda, Aeglidae) Translated title: Population's dynaniics of Aegla platensis Schmitt (Crustácea, Decapoda, Aeglidae)

Translated abstract

The crustaceans of the genus Aegla Leach, 1820, are found in streams, rivers of caves, current rivers and lagoons, from Franca, São Paulo, Brazil (20º60'S, 47º40'W), to Ilha Madre de Dios (5uº01'10"S, 75º18'45"W), Chile in South America. The crabs (Aegla plalensis Schmitt, 1942) were monthly sampled by hand fromjuly 1997 to september 1998 in Arroio do Mineiro, Taquara (29º46'S, 50º53'W), Rio Grande do Sul, Brazil. The sex, the length and width of the carapace were registered. After being collected the animais were returned to the stream. The repro-ductive period, the size at the first maturation and the sex-ratio were identifred. The reproductive period of A. platensis lasts the whole year. The percentage of ovigerous females is higher in july. The size at the first maturation is from 14,40 to 15,60 mm of carapace length. The sex-ratio is 1,08 male to 1 female. The annual population's density is 12 animais per square meter.