Effect of water salinity on mating success of orange mud crab, scylla olivacea (Herbst, 1796) in Captivity

Abstract

This study was conducted to determine the effects of salinity on the mating success of orange mud crab, Scylla olivacea. Male crabs and immature female crabs were reared at the salinity of 15, 20, 25 and 30 ppt in 30 days study period. Brood stocks were fed with squids and maintained until the pre-copulation observed. The pre-copulated crab pairs were isolated from the other brood stock and observation was done for duration of pre-copulation, copulation and post-copulation. The mating duration was recorded. Sperm deposition in the female's spermathecae was also examined. Mating was successful in all tested salinities and mean pre-copulation and copulation period for S. olivacea was 22.4 and 2.9 h, correspondingly. The mating success was 50, 30, 20 and 10% for salinity of 25, 15, 20 and 30 ppt, respectively. However, there were no significant relationship between the salinity level and mating success of S. olivacea where 25 ppt salinity was the optimum salinity preferable by mud crab pairs to achieve successful mating with sperm deposition. © 2014 Academic Journals Inc.