ABSTRACT
Molluscan biodiversity in the subprovinces of the Florida Peninsula The southern and western sections of the Florida Peninsula, including the Florida Keys, contain two separate faunal areas; the Floridian Subprovince (named for Florida) and the Suwannean Subprovince (named for the Suwannee River, which empties into the Gulf of Mexico in northwestern Florida) (Petuch, 2004). Both of these subprovinces are under the inuence of very different physical oceanographic conditions, and this is reected in the great differences in the compositions of their malacofaunas. The Floridian Subprovince is completely within the warm tropical water mass of the Florida Current, which ows northward through the Yucatan Straits and then eastward through the Straits of Florida and along the Florida Keys. The Suwannean Subprovince, on the other hand, is under the inuence of the eastern side of the Gulf Loop Current, which brings cold water southward along western Florida during the winter months. The oceanographic conditions of the shallow Neritic Zone of the Suwannean Subprovince uctuate seasonally, with cold (often below 20 degrees Celsius) temperatures in the winter and hot, tropical (above 25 degrees Celsius) in the summer. In direct contrast, the Floridian Subprovince, particularly the Florida Keys area, retains almost constant tropical-subtropical water conditions during the entire year, with temperatures never falling below 20 degrees Celsius.
