ONTOGENIC AND INTERSPECIFIC VARIATION IN THE PROTECTION OF ANEMONEFISHES FROM SEA-ANEMONES

Anemonefishes are well known for their ability to live unharmed among the stinging tentacles of sea anemones. This study examined whether th ere is ontogenetic and interspecific variation in the protection of an emonefishes from being stung by symbiotic anemones. Ontogenetic variat ion in protection was studied by determining if the tentacles of anemo nes would adhere to the eggs, larvae (0-5 days old), and recently meta morphosed anemonefish juveniles (7-14 days old). Interspecific variati on in protection was examined by forcing juveniles of 10 species of an emonefishes to contact the tentacles of up to 9 anemone species. The t entacle adhesive forces of the anemone species were also measured. The eggs of anemonefishes were protected from all species of symbiotic an emones tested. Larval fishes were captured and killed by anemones, but recently metamorphosed juvenile fishes were protected from certain ho st species. Thus, the anemonefishes developed some form of protection during metamorphosis from a pelagic larva to a benthic juvenile. The j uveniles of only one anemonefish species (Amphiprion percula) were pro tected from all the symbiotic anemone species tested, while most other anemonefish species were stung by at least one anemone species. The e xtreme host specialist, Premnas biaculeatus, was only protected from i ts natural host species (Entacmaea quadricolor) and was stung by 6 oth er symbiotic anemone species. The juveniles of all anemonefish species were protected from E. quadricolor, but only a few fish species were able to contact Stichodactyla gigantea without being stung. Fish that were stung by anemone species with strongly adhesive tentacles (e.g., S. gigantea, S. haddoni), were generally captured and killed. However, there was no correlation between the tentacle adhesive force of an an emone species and the number of anemonefish species that it stung.