Tonic immobility induction and duration on halmahera walking shark (Hemischyllium halmahera)

Tonic immobility is an induce method to achieve a temporary condition of cataleptic-like, which is a sudden loss of muscle tone, as a result of various procedures such as situate the object in an "unnatural" position or situation. This method has been widely applied on elasmobranch species, except for species of Hemiscyllidae. This study was intended to assess the application of tonic immobility on Hemiscyllium halmahera - an endemic shark to Halmahera Islands, Indonesia. Our study has shown that the average induction time ranged from 11.49 to 40.12 seconds, while the hypnosis duration ranged from 6.51 to 28.36 seconds. Based on our results, tonic immobility can be applied as non-lethal method to Hemiscyllium halmahera during capture and physical examination such as morphometric and weight measurement. However, we suggested to investigate further physiology examination such as heart rate, and breathing frequency. during tonic immobility phase on Halmahera walking shark or other reef shark species.