Vol. 8, Special Issue 9, Part P (2024)

Presently the soft-shell production of mud crab (Scylla spp.) are generally carried out in indoor (Polypropylene boxes) or outdoor culture system (ponds). Aslamyah and Fujaya, 2010 and 2014; Fujaya 2011, had developed the spinach extraction method for inducing the moulting and growth of mud crab by adding stimulant in artificial feed or injecting the different hormone to crab. Thus, the present study was carried out to standardize the optimum dose of spinach extract for production soft shell. Spinach extract contains phytoecdysteroid, a substance which is well known to stimulant moulting in crabs. Therefore, the study was conducted using four different doses of spinach extract viz. 0 mg/g control (T₀), 0.015 mg/g (T₁), 0.02 mg/g (T₂) and 0.025 mg/g (T₃). The spinach extract was developed as per the method given by Fujaya (2011) and was administrated through injection at base of coxa of last leg of periopod of mud crab. The growth parameters (weight, weight- gain%, carapace length, carapace length-gain%, carapace width, carapace width-gain %) and moulting period recorded during this experiment. The spinach extraction dose of 0.025 mg/g injected to the crab was found to be better with respect to growth i.e. better weight, carapace length, carapace width as well as weight gain, carapace length gain and carapace width gain. It was also revealed that of the same dose gives early moulting i.e. within 30-32 days. Thus, soft shell production can be expedite by this technique in future.