Cleaner fish are sometimes picky eatersFri 05 Oct, 2018
On coral reefs, some fish play the role of cleaners: they remove parasites, dead skin and mucus from the bodies of their clients. In addition to the nutritious gain, cleaner fish also benefit from a protection against predators: if they want to enjoy the cleaning services, they must abstain from chewing the cleaners! While some cleaner fish provide this service full time, other fish are facultative cleaners, and it is not quite clear why.
In the coral reef of Tobago, researchers studied the behavior of juvenile blue-headed wrasse (Thalassoma bifasciatum), a species presenting a facultative cleaning role. Compared to gobies (Elacatinus evelynae), which are full-time cleaners, the young wrasses seem more selective on their clients, showing a marked preference for three species of surgeonfish (Acanthurus sp.). The researchers also noticed that the wrasses sometimes approached these fish without cleaning. It is therefore possible that these facultative cleaners are driven by the acquisition of a particular food resource, such as a parasite specific to surgeonfish which, unfortunately, are not always infected!
Article submitted by Sophie Labaude
Reference: Dunkley, K., Cable, J., & Perkins, S. E. (2018). The selective cleaning behaviour of juvenile blue-headed wrasse (Thalassoma bifasciatum) in the Caribbean. Behavioural Processes, 147, 5–12.