Cleaners clean cleaner mimics

Cleaning symbioses in the marine environment involve small cleaner fish or shrimp that remove ectoparasites from larger fish. The relationship is considered mutualistic as cleaners gain a nutritious food source, while clients benefit from a reduction in ectoparasites (Grutter 1999). The most common cleaner fish throughout the Indopacific is the cleaner wrasse, Labroides dimidiatus (Fig. 1b). Cleaner wrasse are mimicked by the fangblenny Aspidontus taeniatus (Fig. 1c), which is almost an exact replica of both juvenile and adult cleaner wrasse in body shape and coloration. However, mimics can be distinguished from wrasse by the position of the mouth, which is terminal in the wrasse but sub-terminal in the mimic, and a longer dorsal fin compared to the wrasse, which can be erect when swimming. Cleaner mimics are thought to benefit from this resemblance by approaching and attacking unsuspecting reef fish to feed on scales, body tissue and mucus. Their disguise is also thought to help them enter nest sites of other reef fish and feed on fish eggs (Kuwamura 1983).