A Comparison Of Soft-shell Crab Production Methods: Autotomy, Herbal Extract and Natural Rearing

Abstract

The world market demand for soft-shell crabs is increasing due to their delicate taste and ease of eating. However, the current production methods of soft-shell crabs (mutilation / limb autotomy) is either considered unethical or the waiting period for molting is too long. Thus, this research assessed the effect of mutilation (removal of all appendages except swimming legs), using herbal extract (Vitomolt TM ) as a stimulant for moulting, and without stimulation (control) on growth (body size and weight increment), molting period, molting percentage and survival. It was observed that mutilation method stimulated faster molting in crabs compared using herbal extracts and naturals, however, with a significantly lower increase in body size and weight. Molting rate was highest in crabs subjected to mutilation (92%), followed by those injected with than Vitomolt TM (73%) and control (52%). The survival rate of crabs subjected to Vitomolt TM was the highest (94.8%) compared to mutilation group (91.7%) and control (89.6%). Based on these results, mutilation is not recommended for soft-shell crab production due to their lower body size and weight increment (lesser profit for farmers). The use of herbal extract (Vitomolt TM ) has huge potential as a stimulant for molting in soft-shell crab production as its usage increased survival and molting rate in S. olivacea .