MEPS 235:217-222 (2002)  -  doi:10.3354/meps235217

Parasite distribution on client reef fish determines cleaner fish foraging patterns

Redouan Bshary1,2,*, Alexandra S. Grutter3

1Max-Planck-Institut für Verhaltensphysiologie, Seewiesen, Postfach 1564, 82305 Starnberg, Germany
2University of Cambridge, Department of Zoology, Downing Street, Cambridge CB2 3EJ, United Kingdom
3Department of Zoology and Entomology, The University of Queensland, Brisbane, Queensland 4072, Australia
*Address for correspondence: University of Cambridge, Department of Zoology, Downing Street, Cambridge CB2 3EJ, United Kingdom. E-mail:

ABSTRACT: Recent evidence suggests that cleaner fish Labroides dimidiatus effectively control parasite densities on client reef fish that actively visit them to have parasites and dead or infected tissue removed. These findings support the hypothesis that clients benefit from cleaning. However, they do not show how cleaners reduce the parasite load of their clients. Cleaners could selectively feed on parasites or parasite removal could be a side product of cleaners foraging indifferently on the client surface, resulting in the removal of healthy mucus and scales also. To investigate cleaner fish foraging behaviour, we infected individuals of the surgeon fish Ctenochaetus striatus, with parasitic monogeneans on one body side, while the other body side was parasite free. We then allowed these clients to interact with L. dimidiatus. We found that the duration of interactions depended on parasite load, and that cleaners spent both more time and took more bites per time unit on the infected than on the uninfected side. Our data thus support the idea that parasite abundance determines food patch quality for cleaners. The overall outcome of cleaning interactions is thus likely to benefit the clients.


KEY WORDS: Cleaning behaviour · Cooperation · Mutualism · Selective foraging · Labroides dimidiatus


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