QUANTITATIVE COMPARISON OF THE EPIFAUNA ON THALASSIA TESTUDINUM KONIG IN THREE HYDROGRAPHICALLY DISTINCT AREAS IN SOUTHERN FLORIDA

The invertebrate macrofauna and algal epiphytes occurring on Thalassia in three hydrographically distinct areas in southern Florida were sampled during 14 June-21 June, 1974. A total of 178 invertebrate species was collected. The dominant non-colonial invertebrate taxa were Amphipoda, Isopoda, Mollusca, Polychaeta, and Tanaidacea. These groups included 93.8% of the fauna and 70.4% of the non-colonial invertebrate species. A relatively high faunal homogeneity was observed on each site. Turbidity and the abundance of algal epiphytes were important environmental factors affecting the observed differences in the composition and density of the epifauna between sites. Similarities in diversity (H') between Chicken Key (2.75), Lake Surprise (2.89) and San Carlos Bay (2.93), were presumably due to equivalent substrates with similar degrees of environmental instability. The Thalassia epifauna showed a high degree of parallelism with the Zostera marina epifauna.