The role of host sea anemones in the cleaning mutualism between anemoneshrimp and client fishes

Abstract

Cleaning symbioses may strongly impact the diversity of coral reef fishes, but little is known about the dynamics of mutualistic networks involving cleaner shrimps that form obligate associations with sea anemones. I used field observations and experiments to determine the role of corkscrew anemones Bartholomea annulata in cleaning interactions between anemoneshrimp Ancylomenes pedersoni and a wide diversity of fish clients (>16 families) on Caribbean coral reefs. Client fishes use the large conspicuous anemones, rather than the small associated shrimp, as visual cues to locate the cleaners and as a stimulus to pose for cleaning. Visitation rates by client fishes depend on anemone size and the total number of crustacean associates (5+ species) per anemone, but cleaning rates and duration depend on the number of cleaner shrimp A. pedersoni. I conclude that the dependence of this fish-shrimp cleaning interaction on host anemones and their endosymbiotic zooxanthellae represents a complex mutualistic network.