SHEPHERD, A.; COELHO, V.R.*; Dominican University of California; Dominican University of California: Comparison Between the Algal Epifaunal Communities Found on Caulerpa cupressoides and Caulerpa sertularioides at Owen Island, Little Cayman, Cayman Islands

The structure of invertebrate communities associated with algae is influenced by the plant�s architecture and chemical (secondary) compounds. Algae species belonging to a same genus are likely to have more similar secondary compounds than unrelated species, and in this case a comparison between the epifaunal communities found in these plants may be more influenced by algal morphology. We analyzed the structure of the invertebrate communities found associated with two species of Caulerpa with different morphologies; one with globular branchlets, C. cupressoides, and other with a feather-like shape, C. sertulariodes. Both algal samples were collected adjacent to each other in an intertidal area at Owen Island, Little Cayman, Cayman Islands. The epifauna was removed from the algae by soaking the samples in freshwater and filtering the water through a set of sieves of 2.8 mm and 250 μm mesh size, respectively. The material retained on the sieves was fixed in alcohol 70% and sorted at the lab. The algae samples were dried and weighed. Estimates of algal surface area and volume were calculated. Crustaceans and polychaetes were the dominant groups in both algae. Some invertebrate species were more abundant or occurred in only one of the Caulerpa species. Caulerpa cupressoides had greater epifaunal abundance, which was independent of algal mass, area or volume. The more complex structure of this alga species may account for the former observation.