POPULATION DYNAMICS AND SECONDARY PRODUCTION OF UCA RAPAX (BRACHYURA: OCYPODIDAE) IN A TROPICAL COASTAL LAGOON, SOUTHEAST BRAZIL

The population dynamics and secondary production of the fiddler crab Uca rapax Smith, 1870 in the Itaipu Lagoon (Southeast Brazil) were studied. Samples were taken monthly over a period of 12 months, in order to test latitudinal gradient predictions about secondary production and P/B ratio. Males and females showed the same growth rates (K = 2.083) and reached the same asymptotic size (15.57 mm). However, females showed higher total (Z = 3.20) and annual mortality (A = 0.96 ind.year(-1)) than males (Z = 1.89; A = 0.85 ind.year(-1)). Recruitment occurred in all months, except in June, 2007. Secondary production was estimated in 113.4 g AFDW.m(-2).year(-1) and the production to biomass ratio (P/B) was 15.09. The production and P/B ratio estimated in the present study did not agree with the latitudinal gradient literature predictions.