Marine amoebae from Georgia coastal surface waters

Abstract

Recent studies on marine protozoa in planktonic ecosystems have focused primarily on taxonomy of ciliates and flagellates and their role in aquatic food webs. Comparable studies of marine amoebae however, have received considerably less attention. The present investigation was carried out in the coastal waters of Sapelo Island, Georgia to obtain a data base and to assess the diversity of genera and species of marine amoebae in the nearshore waters of the southeastern United States. Twenty-nine species, representing 15 genera of marine amoebae, were identified from Georgia coastal surface waters. Paramoeba aestuarina, Platyamoeba langae, Clydonella vivax, Vannella mira, and Mayorella gemmifera, were the most common species observed in culture. The taxonomy of western European marine amoebae was studied by Page (1983), who published an extensive illustrated and descriptive key to most wellknown species. Bovee & Sawyer (1979) published a key to the marine amoebae of the northeastern United States, and Davis et al. (1978) published an account of species recovered from surface and deep waters of the open Atlantic Ocean. More recently, Fernandez et al. (1989) identified well-known and apparently widespread species from the northwest coast of Spain. Sawyer (1990) reviewed the historical significance of "old" and "new" species of marine amoebae. The present study probably is the most extensive survey of marine amoebae from warmer waters of the southeastern Atlantic coast of the United States, with the exception of Schaeffer's (1926) studies in more southern waters of Tortugas Key, Florida. Sapelo Island is an Atlantic barrier island located off the coast of Georgia approximately 80 km south of the industrial port of Savannah. Its shoreline is a typical tidal marsh, where waters are influenced by freshwater runoff and saltwater intrusion at high tide. The island is sparsely inhabited by humans, but has a significant vertebrate fauna, including white tail deer, migratory waterfowl, alligators, and other reptiles. Annual temperatures vary from below freezing in the winter to over 37?C in the summer. The island and its coastal waters are ideally suited for studies of freshwater, soil, and marine protozoa in environments that are relatively free from influences of human activity. The present paper summarizes a three-month investigation (February-May 1987) of the diversity of amoeboid protozoa in both coastal and offshore surface waters surrounding the island. MATERIALS AND METHODS Surface water samples of approximately 250-500 ml were collected in sterile glass bottles and filtered through 0.80-,um filters (Millipore Corporation, Bed' The author expresses sincere appreciation to the University of Georgia Marine Institute at Sapelo Island for allowing him to be a Visiting Scientist during the course of this investigation. Special appreciation is extended to the Director, Dr. James Alberts, and to Drs. Evelyn and Barry Sherr for their hospitality and encouragement. TRANS. AM. MICROSC. Soc., 111(4): 360-364. 1992. ? Copyright, 1992, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.176 on Mon, 20 Jun 2016 07:33:44 UTC All use subject to http://about.jstor.org/terms VOL. 111, NO. 4, OCTOBER 1992 6 Gray'. Reef (34 km oflshore) ..SAPELO ISLAND (South End)