Distribution, Population and Reproductive Biology of the Fiddler Crab Uca sindensis (Crustacea: Ocypodidae) in a Subtropical Mangrove of Pohl Area

Distribution, population and reproductive biology of Uca sindensis were studied in a subtropical mangrove of Pohl port in the northern Persian Gulf. Sex ratio, distribution, population structure, handedness (evenness), diameter burrow, breeding season and fecundity were investigated. Ten 0.5 m2 quadrates were randomly sampled during low tide periods from October 2009 to September 2010.A total of 711 crabs, 344 (47.7%) males and 367(52.3%) females, were sampled. The CW of males ranged from 4 to16 mm and of females from 5 to 17 mm indicating sexual dimorphism. The overall sex ratio was 1:0.93 and did not differ significantly from the expected 1:1 (χ test, P>0.05), however the monthly sex ratio was different from expected 1:1(χ test, P<0.05). Results indicated that the size frequency distributions of this species could also be determined through direct analysis of burrow openings (r2=0.99). Breeding took place during warm season of April 2009 to September 2010. Egg numbers increased with female size(r2=0.50). The regression analysis showed that the number of eggs increased linearly with the increase of carapace width (r2= 0.766, EN= 0.1125 CW-0.1129, n=31). It was concluded that two factors of temperature and TOM affected growth and reproduction pattern in U. sindensis.