Acclimation and growth of hatchery produced false clown Amphiprion ocellaris to natural and surrogate anemones

Abstract

Anemonefishes live unharmed among the tentacles of sea anemones. Among the tested natural sea anemones, Heteractis magnifica, H. crispa and Stichodactyla gigantea were found as suitable hosts for acclimation and rearing of hatchery produced false clownfish Amphiprion ocellaris under captive conditions and the maximum settlement (100% on 6th day) was obtained by using H. magnifica. To study the acclimation time and behaviour, A. ocellaris were allowed to associate with surrogate anemone prior to being reared with natural anemone H. magnifica. The average acclimation time in surrogate and natural anemone was 6472.3 and 102.4 minutes respectively in comparison with 18.7 minutes for those fish that were allowed to orient to the surrogate anemone prior to being with natural anemone H. magnifica. The study revealed that exposure of A. ocellaris to surrogate anemone resulted in substantial decrease subsequently in the time of acclimation to a natural sea anemone. This result shows that the fish is responsible for developing its own protection from sea anemone’s mucous during acclimation. There was considerable difference in growth among the juveniles as well as between the individuals reared in natural and surrogate anemones. Higher growth was obtained in fishes acclimated to natural anemones followed by surrogate anemone, whereas fishes reared without sea anemone showed less growth. This difference could be attributed to the social inhibition of growth of subordinate late settlers by frequent attack from the dominant early settlers. The present study also concludes that in the absence of natural host-specific sea anemones, the surrogate anemone may be used as a substitute to rear fishes under captive conditions.