ESTUDOS POPULACIONAIS DE Macrobrachium birai LOBÃO, MELO & FERNANDES E Macrobrachium petronioi MELO, LOBÃO & FERNANDES DAS REGIí­-ES DE CANANÉIA E JURÉIA (SP í BRASIL): II í DINÂMICA DO CRESCIMENTO

Abstract

With the aim of knowing the growth dynamics of M. birai and M. petronioi from Rio Branco (Cananéia-SP) and Rio Verde (Juréia-SP), monthly captures were made from July/1985 to March/1988 and September/1987 to August/1990, respectively. The relative growth of weight/length variables was of allometric type to both species and populations, except to females of M. petronioi from Cananéia. Maximum sizes reached were assigned to males, with 8.30 cm and 5.55 cm to M. birai and 7.00 cm and 5.85 cm to M. petronioi from Cananéia and Juréia, respectively. The relationship between the cephalotorax, abdomen and telson lengths and the total/length showed an isometric type of growth, indicating the abdominal portion as the part which develops the most on females of the two species and populations studied. The same was noted on males of M. petronioi from Juréia, whereas the rest of male populations presented a larger cephalotorax portion. The modal distribution of total length showed more occurrence of adult individuals in the same seasons assigned to reproductive period for these populations