Revista Brasileira de Zoologia
versão impressa ISSN 0101-8175
PINHEIRO, Marcelo A. A. e TADDEI, Fabiano G.. Growth of the freshwater crab, Dilocarcinus pagei Stimpson (Crustacea, Brachyura, Trichodactylidae). Rev. Bras. Zool. [online]. 2005, vol.22, n.3, pp. 522-528. ISSN 0101-8175. http://dx.doi.org/10.1590/S0101-81752005000300002.
The biology of freshwater crab Dilocarcinus pagei Stimpson, 1861 has been poorly studied, mainly in relation to growth in the Trichodactylidae species. This study aims to determine size/weight growth curves, longevity and age in the puberty molt of the freshwater crab Dilocarcinus pagei Stimpson, 1861. The samples were taken monthly in the São José do Rio Preto county dam (São Paulo), from October 1994 to September 1996, the individuals being sexed, measured (CW = cephalotorax width) and weighed (WW = wet weight). Growth was determined by distribution of the specimens by size classes, where as the FiSAT program was used to determine non-linear estimation of growth parameters by the Bertalanffy equation. A total of 962 specimens (534 males and 428 females) was analyzed. Growth size curves were expressed by the equations CWMales = 61.7[1-e-0.97(t+0.041)] and CWFemales = 57.1[1-e-1.41(t+0.031)], while growth in weight was better represented by WWMales = 65.2[1-e-0.97(t+0.041)]3.08 and WWFemales = 44.9[1-e-1.41(t+0.031)]2.82. Assintotic size of the males (61.7 mm) was greater than that of the felamles (57.1 mm), the opposite occurring for longevity, estimated at 2.4 and 2.7 years, respectively. The maximum size (95% of the CW¥) was 58.6 mm for males and 54.2 mm for females, very close to maximum sizes recorded in nature to each sex (55.8 mm). The puberty molt in males occurred at a higher age level when compared to that of females (tMales = 1.2 years and tFemales = 0.9 years). The results present here are inedited in the carcinological literature, this being very important in population management and preservation of this species, as it is explored intensely and used as bait in fishing.
Palavras-chave : Age; size; weight; Bertalanffy.