Natural and Induced (Eyestalk Ablation) Molt Cycle in Freshwater Rice Field Crab Oziothelphusa Senex Senex

In crustaceans, molting is the process of shedding old exoskeleton and is required for the somatic growth of new exoskeleton for its growth.The molting processes in crustaceans vary from one species to other and also vary with the environmental conditions.In the present study the molt cycle of freshwater crab Oziothelphusa senex senex was studied.The size of crabs selected for the study is 30 ± 2 g.The natural molt cycle is consisting of intermolt (C1, C2, C3 and C4), premolt (D1, D2, D3 and D4), ecdysis (E) and post molt (A1, A2, B1 and B2) stages were measured and the percentage of each stage in the molt cycle was calculated.The biggest stage in the O. senex senex molt cycle is intermolt stage (90.0%) and shortest one is ecdysis (0.01%).Induced molt cycle was studied by eyestalk extirpation (ESX) and observed that 60.71% of male crabs and 52.0%female crabs were molted after 28th day of extirpation suggesting the role of eyestalk principle in regulating the molting process.