FECUNDITY ESTIMATION IN TWO CRAB SPECIES FROM A SUBTROPICAL MANGROVE

NEGREIROS-FRANSOZO MARIA LUCIA; GUIMARAES FERNANDA; COLPO KARINE

PUERTO VALLARTA - MEXICO

Congreso; The Crustacean Society 2000 Summer Meeting; 2000

Fecundity has been extensively used as an indication of the reproductive potential in Decapod species. However. some standardization is needed. mainly concerning to the adequate embryonic stage to achieve the number of eggs exteriorized by a female per spawning. The use of egg mass in the intermediate or final embryonic stage could underestimate the actual number of eggs as some of them are often lost throughout incubation. In this sense, the present work was performed to compare the fecundity of two crab species (Aratus pisonii and Uca thayeri) in two embryonic stages: initial and final. Ovigerous females from Ubatumirim mangrove (Slio Paulo. Brazil) of one same size range (A. plsonii, 19 to 21 mm of carapace width; V. thayeri. 17 to 20 mm) had their eggs counted using a Motoda sampler apparatus. The mean fecundity for A. pisonii was 20,185.6 ±4,487.5 eggs (initial stage) and 13,440 ±6.382.9 eggs (final stage), which differ statistically (p=O.0476). The mean fecundity for V. thayeri was 22,278.4 ± 4,3598 eggs (initial stage) and 17,440 ± 4,5694 eggs (final stage), which did not differ statistically (p=O.063). Nevenbeless. the variation coefficient found for final stage for both species is high (> 30%), what suggest that the initial embryonic could be more feasible to assess fecundity in the studied species