Meeting Abstract
Caribbean Anolis lizards have become a model system for the study of adaptive radiation and coevolution, whereby anoles have diversified to specialize in the use of different parts of their structural habitat. The resultant ecomorphs exhibit consistent morphology-to-habitat use relationships on each island, such that the same ecomorph on different islands look remarkably similar. They also exhibit similar morphology-to-performance relationships whereby their performance capabilities are closely related to their morphology and vary among ecotypes. Unlike other Caribbean islands, the island of Martinique is host to a single species, Anolis roquet. Across the island, however, A. roquet inhabits disparate environments. The lizards that occupy these differing habitats show noticeable variation in their physical characteristics, having previously been described as six different subspecies and as different ecotypes. We examined the morphology, sprint and bite performance, and muscle contractile physiology of two forms of A. roquet from a montane forest habitat and a xeric coastal habitat. We found significant differences in morphological dimensions, along with differences in some whole organism performance measurements between these two forms. Muscle contractile physiology, on the other hand, generally did not vary between these forms. Differences appear particularly prominent in head dimensions and bite force, possibly due to these forms specializating to different prey items or varying in their conspecific interactions. These results suggest that morphology and performance may specialize to novel environments and functional demands before muscle contractile physiology. Such patterns thus provide insight into the process of adaptive radiation and the effects of habitat variation on Anolis lizards in the absence of species level divergence.
