Thanatosis in juvenile notolabrus celidotus, the New Zealand spotty wrasse

Abstract

The present study reports a decrease in activity and sudden immobile state, known as thanatosis, in the New Zealand endemic wrasse, Notolabrus celidotus. We observed tonic immobility immediately after wrasse collection in field studies. Escape is the primary defence of juvenile N. celidotus and our observation suggests that thanatosis can be a secondary strategy when the first has failed. The response occurred after N. celidotus was manipulated by being removed from a fishnet and placed into buckets, allowing for the conclusion that N. celidotus may use thanatosis as a secondary defence strategy following physical restraint events.