Multiple cleaner species provide simultaneous services to coral reef fish clients

Cleaning symbioses on tropical coral reefs are typically documented between two species: a single client fish and one or more conspecific cleaners. However, multiple Caribbean cleaner species often live sympatrically and have been anecdotally reported to simultaneously clean the same client. The patterns and processes driving these interactions are poorly understood and cleaning interactions involving multiple cleaner species may be subject to different driving forces than those involving a single cleaner species. Here we used remote underwater videography on three reefs in Honduras to record simultaneous cleaning interactions involving Pederson’s cleaner shrimp (Ancylomenes pedersoni) and cleaner gobies (Elacatinus spp.). Our multi-year dataset shows cleaner gobies joined 28% of all interactions initiated at A. pedersoni cleaning stations with cleaner gobies residing nearby, and 9% of all cleaning interactions across our study sites. Client body size significantly predicted simultaneou...