Tonic Immobility in Newly Emerged Sea Turtle Hatchlings

Abstract

The ability for animals to become temporarily immobile via external stimulus is known as tonic immobility (TI) and has been widely described among different taxa. However, TI is poorly documented in turtles. We demonstrate TI in newly emerged green turtle (Chelonia mydas) hatchlings in relation to potential practical applications and discuss the methodology of how to induce TI. On average, combining all clutches sampled, TI induced green turtle hatchlings to remain immobile for 25 ± 12 sec; thus, we argue that in this state of immobility, researchers and conservationist can safely obtain quantitative variables (e.g., animals' weight and morphological measurements without forceful stressing or harming the animal).