BIODIVERSITY OF PLANKTONIC DINOFLAGELLATE SPECIES IN MANGROVE PONDS,PELICAN CAYS,BELIZE

Information on the population structure of planktonic dinoflagellates is reported in the coral reef‐mangrove ecosystem at Pelican Cays, Belize. Six sites examined included: Cat Cay, Douglas Cay, Elbow Cay, Fisherman's Cay, Lagoon Cay and Manatee Cay. A spectacular and rich dinoflagellate taxa including oceanic, coastal and offshore species are illustrated. The presence of oceanic species in the studied cays is an unexpected observation since dinolfagellate assemblages are virtually enclosed within ponds bordered by coral ridges that limits water exchange with the open ocean except during storm events. I am also reporting significant differences in the dinoflagellate associations among the studied cays. Dominant taxa included 16 Proroperidinium species, 11 Gonyaulax species, and ten Ceratium species. Only six planktonic species were harmful. Bloom forming species included Ceratium furca and Gonyaulax polygramma. A much more diverse authotrophic and heterotrophic dinoflagellate population characterizes the Pelican Cays than previously suspected. Some species are reported the first time: Protoperidinium belizeanum sp. nov., P. pyrum Balech, P. steidingerae Balech, P. depressum (Bailey) Balech, and P. divergens (Ehrenberg) Balech. These results demonstrate that the Belizean coral reef‐mangrove ecosystem is a delicate and species‐rich environment, and as such, should be protected and preserved.