MEPS 262:267-275 (2003)  -  doi:10.3354/meps262267

ABSTRACT: Many direct costs of parental care have been described for teleost fishes, including reduced body weight, body fat and immune condition. However, few studies have focussed on the indirect consequences of reproduction. In this study, we investigated such consequences in the longfin damselfish Stegastes diencaeus (Jordan & Rutter), a territorial reef fish in which the males provide parental care of eggs. More specifically, we examined patterns of spatial distribution of males and females in relation to substratum suitability for the establishment of nest sites and the consequences of spatial distribution for ectoparasite burden and cleaner-seeking activity. The territories of males and females differed significantly in a number of habitat features. Breeding males, with a nest site present in their territory, were found mainly at the periphery of reef patches, near sand, where vertical substratum suitable for nest sites is present, whereas females and non-breeding males were found in the centre of patches. Cleaning stations occupied by the cleaning gobies Elacatinus evelynae and E. prochilos were also located in peripheral areas, thus, in general, breeding males were closer to cleaning stations than females. Damselfish that were closer to cleaning stations visited them more frequently. During nest-guarding periods, males visited cleaning stations less frequently than during non-guarding periods, but this was not concomitant with an increase in ectoparasite loads during nest-guarding periods. Damselfish in peripheral territories had significantly lower ectoparasite numbers than those situated in the centre of reef patches. These results are consistent with a lower exposure of peripheral damselfish to ectoparasites. These intersexual differences in territory position, proximity to and use of cleaning stations, and ectoparasite loads are indirect consequences of sex differences in reproductive-resource requirements. Such interactions between breeding systems, distributional ecology and other aspects of non-reproductive behaviour are undoubtedly widespread, and their consideration could enhance our general understanding of reef-fish ecology.

KEY WORDS: Cleaning stations · Paternal care · Reef fish distribution · Stegastes diencaeus · Sex differences · Territoriality