Adnan Amin-Safwan, Harman Muhd-Farouk, Nurul Hasyima-Ismail, Hairul Hafiz Mahsol, and Mhd Ikhwanuddin

DOI: 10.14456/sjst-psu.2019.154

pp. 1226 - 1232

Abstract

This study describes the relationships between the carapace width (CW) and body weight (BW) increments and the
confirmation of Stage 1 ovary after the molting of immature orange mud crabs, Scylla olivacea, in captivity. Morphological
coloration and histological assessments were done on 165 immature female S. olivacea. Healthy crabs were sampled from the
Setiu Wetlands in the coastal waters of Terengganu on the Malaysian Peninsula from July to September 2015. Thirty crabs were
sacrificed for a preliminary study as a standard (control) in which the gonads (if available) were dissected for histological study.
The remaining crabs (n=135) were selected for subsequent analysis (limb autotomy). Compared to the controls, the molted crabs
generally did not produce any difference in the stage of the ovaries (remaining in Stage 1) but were observed to have larger
oocytes. This demonstrated that the limb autotomy technique may activate hormone regulation, thus triggering vitellogenesis in
the mud crab. There were also positive correlations between CW and BW (P=0.001, P<0.01) and significant differences through
regression analysis (P=0.002, P<0.01) with the equation y = 2.61x + 6.27 (R²=0.069). These results can be useful for developing
baseline data for further crab management in Malaysia.