INTERACTIONS BETWEEN CLEANING GOBIES AND TERRITORIAL DAMSELFISH ON CORAL-REEFS

We studied the interactions between cleaning gobies, Elacatinus spp.. at cleaning stations and territorial dusky damselfish, Stegastes fuscu s, on a Barbadian fringing reef to;enhance our understanding of the be havioural impact of cleaning stations on members of a coral reef commu nity. Cleaning stations within damselfish territories were visited by significantly fewer species and fewer individuals than those outside d amselfish territories. At cleaning stations within damselfish territor ies, the main client was the territory holder itself. Client behaviour did not differ between the two types of cleaning station; however, cl eaning gobies at stations within damselfish territories spent less tim e cleaning clients? their cleaning bouts were shorter, and their feedi ng rate on clients was slower. These effects appear to be due to the r epeated aggression of territorial damselfish towards fish intruding on to their territories to visit cleaning stations. The overlap between a territorial damselfish and a cleaning station therefore appears to h ave detrimental impacts on cleaning goby foraging. The presence of cle aning stations within damselfish territories exerted some effects on t he territory owners. Although the rates of intrusions were similar on territories with and without cleaning stations, damselfish with cleani ng stations tended to chase intruders more often, had a lower foraging rate, and were at higher risk of egg predation because of increased i ntrusions by egg predators. A potential benefit to territorial damself ish is regular access to a cleaning station; however, the magnitude of this benefit is unknown. This study reveals that damselfish, which ar e ubiquitous on coral reefs, can generate significant variation in lev els of use of cleaning stations, which leads to new questions relating to the settlement behaviour of both cleaning gobies and damselfish. ( C) 1998 :The Association for the Study of Animal Behaviour.