Reproductive aspects of freshwater shrimp Macrobrachium potiuna (Muller) (Crustacea, Decapoda, Palaemonidade) in Serra do Piloto, Mangaratiba, Rio de Janeiro, Brazil

摘要

Samples of Macrobrachium potiuna (Muller, 1880) were collected monthly from July/2001 to June/2002. At the laboratory, shrimps were separated by sex and measured. The ovigerous females were separated and theirs eggs measured and counted. A total of 1162 shrimps were collected, 50% was females, 47% was males and 3% juveniles. The reproductive period occurred during the spring-summer. The ovigerous female showed total length from 25.9 to 40.3 mm. The mean fecundity was 24,0 ± 9,0 eggs. The first sexual maturation occurred at 25.9 mm total length. The eggs showed means dimensions from 1.56 and 2.08 mm, respectively, for the short and the long axis during the initial stage of development and from 1.70 and 1.89 mm, respectively, for the short and long axis during the final stage of development.