Response to autotomy in anesthetized freshwater crab, Paratelphusa hydrodromous (Herbst)

To extend the knowledge of amputation and induction of autotomy, the freshwater crab Paratelphusa hydrodromous (Herbst) was chosen as a model system. Amputation of different legs of Paratelphusa hydrodromous (Herbst) was done in two conditions; normal and anesthetized crab. Autotomy of the amputated legs under normal condition was induced autotomy within seconds (1.6 to 37 seconds). However, the amputation conducted in ice cold anesthetized crab showed delayed autotomy in a wide range of time from 10.2 ± 0.83 minutes (cheliped) to 114.8 ± 4.3 minutes (2nd walking leg). The observations suggest that ice cold anesthesia lowers the signaling of pain to the brain and delays autotomy, the voluntary mechanism to escape from the predator/pain or frightened force.