Relative growth of the fiddler crab Uca rapax (Smith) (Crustacea: Decapoda: Ocypodidae) in a tropical lagoon (Itaipu), Southeast Brazil

The relative growth of the fiddler crab Uca rapax from a population of a tropical lagoon system of southeast Brazil was determined. Carapace height (CH), length (LMC) and height (HMC) of the major cheliped of males and abdomen width of females (AW) were employed as dependent variables and carapace width (CW) as independent variable. A total of 634 crabs, 357 males and 277 females, were sampled. The CW of males and females ranged from 2.61 to 21.94 mm (10.30 + 2.53 SD) and from 2.24 to 18.22mm (9.31 + 2.23 SD), respectively. The relationship between CW and LMC showed positive allometry in juveniles (logLMC = -0.6634 + 1.857logCW) and negative one in adult males (logLMC = 0.4570 + 0.8465logCW). The females showed allometric positive growth for CW x AW in juveniles (logAW = -0.7485 + 1.4410logCW) and adults (logAW = -0.4222 + 1.3127LogCW) with reduction of the allometry level in the adult phase.