Inventariamento e biologia dos camarões de água doce da família palaemonidae (crustacea, decapoda) do Mocambo, Belém, Pará

Abstract

In order to provide scientific knowledge about the biology of freshwater Palaemonid shrimp in the Mocambo Reserve (APEG), municipality of Belém, Pará, a study was proposed to identify the species in the area and to determine the most abundant species, the reproductive period, the average size at first maturity and fecundity. Collections were carried out monthly from July 1998 to April 1999, for 2 hours/day/month, using a 2mm mesh puçá. The specimens were placed in perforated plastic bags and packed in a tarragon or bucket containing I 4% form for fixation and transportation. In the laboratory, the specimens were identified, sexed, counted and biometrically measured. As preliminary results, a total of 947 specimens belonging to the genera Palaemonetes and Euryrnhynchus were obtained. The former represented by Palaemonetes carteri with 376 females, 337 males and 32 specimens without sexual determination, and the latter represented by Euryrhynchus burchelli with 91 females, 90 males and 03 undetermined, and Euryrhynchus amazoniensis with 10 females and 08 males. Ovigerous females of Palaemonetes carteri occurred in two periods during the year, a period from July to September and another from January to February; February being the reproductive peak. The average carapace length was 6,270.57mm, and that of the smallest ovigerous female captured was 5.25mm. However, the average size of 1st maturation occurred between 5.76 - 6.00 mm of carapace length. Fecundity was established by the ratio of number of eggs/carapace length (mm) and showed a low significant value (R2 = 0.277).