Mimicry in juvenile wrasses: ecological and behavioural aspects of a Coris-Amphiprion relationship in the northern Red Sea

Evidence of mimicry in the literature is often anecdotal and based on general resemblances and observer intuition. Every case of mimicry is unique and has to be proved based on certain ecological characteristics that apply to all real mimic-model relationships. The present study hypothesises that the colour similarities of juveniles of the wrasse species Cons cuvieri (Bennett, 1831) to the Anemone fish Amphiprion bicinctus Ruppell, 1830 in the northern Red Sea represents a real case of mimicry. C. cuvieri takes advantage of its conspicuous colouration (as resembling Anemone fish) in order to avoid possible predators. This study examines the ecological and behavioural relationship between the mimicking species C. cuvieri and its model A. bicinctus in the Gulf of Aqaba. Juveniles mimic the colouration of Anemone fish throughout the geographic range of the wrasse. Mimics and models occupy the same habitats and prefer the same depths and reef zones. The wrasse undergoes a transition from the juvenile (mimetic) colouration to the adult species-specific (non-mimetic) colouration when they reach a critical size (the maximum size of the Anemone fish). As typical of mimic-model relationships, mimic wrasses were always less abundant than their model. Mimics were found in loose association with Anemone fish and spatial variation in the abundance of mimics was correlated with models, while the abundance of other wrasses was not. Juvenile wrasses gain a foraging advantage by mimicking Anemone fish which is explained by the decrease of the predation risk and the deception of competitors. Predators recognise the typical Anemone fish colouration and learn not to attack as they experience low catch-per-unit success rates.