Acclimation behaviour and bio-chemical changes during anemonefish (Amphiprion sebae) and sea anemone (Stichodactyla haddoni) symbiosis

Abstract

Anemonefishes are known to exhibit an obligate symbiotic relationship with a limited number of sea anemone species. This has raised queries about the adaptive mechanisms of these fishes involved. The present study was carried out to understand the role of visual and chemical cues used for host recognition and the bio-chemical changes that occur during acclimation by the fishes. The experiments used the fishes Amphiprion sebae (a common anemone associate), Terapon jarbua (a control fish that does not associate with sea anemone) and Stichodactyla haddoni (an anemone commonly hosting anemonefishes). The results suggested that fish settlers use visual, tactile and chemical cues to select and distinguish their hosts. Furthermore, the acclimation times of A. sebae with the anemone host decreased exponentially during repeated trials. This fish apparently secreted a protective mucus. The epidermal mucus of A. sebae possessed unique glyco-proteins compared with T. jarbua. Chemical analyses showed that A. sebae and S. haddoni produced similar chemical substances, but T. jarbua produced a different kind of glycoprotein. This study helps to explain how anemonefishes are able to live with their host anemone, whereas other fishes are not.