Habitat fragmentation and body‐shape variation of African hindCephalopholis taeniops(Valenciennes) in an archipelago system (Cape Verde, eastern Atlantic Ocean)

Abstract

Morphological variations of the serranid fishCephalopholis taeniopswere studied in relation to habitat fragmentation in the Cape Verde Archipelago. While a significant allometric effect existed (11·5% of total body‐shape variation), differences in morphology associated with sex and ontogeny were not significant. MANOVA followed by CVA showed that each island presented a particular allometric pattern. Average body shape for all islands was well discriminated with CVA models. Pair‐wise comparisons of the ontogeny of morphological change between islands revealed that northern islands (Santo Antão, São Vicente and Santa Luzia) along with Boavista Island showed a similar direction in shape ontogeny, while all other paired comparisons indicated different ontogenetic patterns. When comparing directions of inter‐population shape changes, individuals from Fogo Island, the southernmost locality, departed far from the orthogonal relation, suggesting that they were undergoing independent body‐shape trajectories. Physical isolation by geographic distance and depth was positively correlated with morphological divergence among populations from different islands. This finding supports the hypothesis that habitat fragmentation in the Cape Verde Archipelago can be interpreted in terms of marine population structure.