Fine Structure of Small Free-Living Paramoeba (Amoebida) and Taxonomy of the Genus

Abstract

INTRODUCTIONAmoebae of the genus Paramoeba Schaudinn, 1896, are among the Gymnamoebia most frequently isolated from marine habitats, and individual species have a wide distribution throughout the world. Unlike many genera of Gymnamoebia, Paramoeba is exclusively marine. The type species, P. eilhardi Schaudinn, 1896, was originally described from a marine aquarium in Berlin with no further information on origin (Schaudinn, 1896); it has been found in the Mediterranean off France (Chatton, 1953; Grell, 1961) and Italy (Grell & Benwitz, 1970) and the Indian Ocean off Madagascar (Grell & Benwitz, 1970). P. schaudinni de Faria, da Cunha & Pinto, 1922, originally described from a sea-water aquarium at Rio de Janeiro, has recently been reported from the Gulf of Mexico (Sawyer, 1980). P. pemaquidensis Page, 1970, has been found on the coasts of Maine, U.S.A. (Page, 1970), Norfolk (Page, 1973), and Essex (Page, unpublished); in open waters off the eastern coast of the U.S.A. (Davis, Caron & Sieburth, 1978); in marine sediments of the western North Atlantic, the Bight of New York, and the Gulf of Mexico (Sawyer, 1980); and in the present study on the shores of North Wales and western Scotland. Paramoeba aestuarina Page, 1970, though not found as often as P. pemaquidensis, is also widely distributed (Page, 1970; Davis et al. 1978; Sawyer, 1980). The first European finding of P. aestuarina is reported in the present paper, but the exact origin of the strain is uncertain. P. perniciosa Sprague, Beckett & Sawyer, 1969, which appears to be an obligate parasite, has thus far been reported only from crustaceans off the eastern coast of the U.S.A. (Sprague, Beckett & Sawyer, 1969; Sawyer, 1976).