Morphological plasticity in the reef zoanthid Palythoa caribaeorum as an adaptive strategy

We compared morphology of Palythoa caribaeorum (number of polyps, area, diameter and height) occupying three sites located at different distances from a harbor area and with different environmental conditions, such as sedimentation. Seasonality was also considered by comparing morphology during the wet and dry seasons. GLM analyses showed significant main and first-order interaction effects between sites and seasons for each of the four morphological variables measured. Only at the site directly in front of the harbor area there was no seasonal variation. At the other two sites, no significant differences were found when the average pairwise distance of each morphological character was compared between seasons for each site. This indicates that these characters vary in a similar way and suggests growth conditions intrinsic to the species. Environmental homogeneity at the harbor area seems to promote homogeneous morphometry, which indicates different biological strategies and suggests that this species adapts to distinct environments.