Assemblages of reef fish settling on artificial substrates: effect of ambient habitat over two temporal scales

摘要

Artificial habitats provide a unique opportunity to investigate how habitat characteristics structure juvenile fish assemblages after settlement. We quantified the differences between assemblages of juvenile fish on artificial substrates moored in macroalgal beds, seagrass beds or coral patches over two temporal scales that corresponded to a short (48 h) and a longer (>2 weeks) immersion time, respectively. The highest abundances were obtained from artificial habitats moored in seagrass beds, whatever the immersion time was. Total abundances of juveniles increased 3-fold between a short and a long immersion, suggesting a net accumulation of individuals with time. Moreover, significant differences in juvenile fish assemblage structure were observed between habitats and between immersion times. Artificial habitats may reflect species-specific habitat preferences at settlement at a meso-scale; however, caution must be paid to the effects of ambient habitat and post-settlement processes on juvenile fish assemblages observed on artificial habitats.