Habitat choice in adult longfin damselfish: territory characteristics and relocation times

Abstract

Habitat selection by coral reef fish during initial settlement has been shown to depend on various biotic and abiotic characteristics. However, relatively little is known of the factors influencing habitat choice by adults during post-settlement processes such as relocation or migration. In this study, we first characterised the habitat of longfin damselfish ( Stegastes diencaeus Jordan and Rutter) territories to quantify territory variability. Characteristics such as percentage cover of rock, sand, live coral and distance from sand were highly variable, while territory area, turf and macro algae cover were relatively uniform across territories. We then assessed the importance of specific habitat characteristics by experimentally removing damselfish and measuring recolonisation times in relation to these characteristics. The presence of nest sites markedly increased the speed of territory recolonisation after experimental removals. Other variable territory characteristics such as substrate type, rugosity and the presence of cleaning stations did not affect recolonisation speed. In general, males recolonised territories faster than females, and males were more likely to recolonise territories previously owned by males with an active nest site. Thus, intraspecific competition for high-quality nest sites may generate sex differences in territory relocation and highly stable sex-specific patterns of adult distribution.