Tintinnoinea
Introduction

Tintinnids are lorica-building, planktonic oligotrichid ciliates ranging in size from 20 to 200 µm. They constitute a major component of the microzooplankton in most marine environments (Beers and Stewart, 1967; Beers, 1982; Beers et al., 1982). They can also be important occasionally in estuarine and brackish waters (Souto, 1973, Barría de Cao, 1981). Short generation times, high abundances, and fast reproduction rates, coupled with high grazing impact, enhance the importance of tintinnids as a key trophic link between the microbial and the metazoan compartments (Heinbokel and Beers, 1979; Bröckel, 1981; Capriulo, 1982; Capriulo and Carpenter, 1983; Paranjape et al., 1985; Porter et al., 1985; Laval-Peuto et al., 1986; Paranjape, 1987a, b; 1988; Garrison and Gowing, 1993).

Tintinnid abundance in plankton samples, widespread geographic distribution, and easily preserved loricae probably account for numerous publications, particularly on their taxonomy. Systematic surveys have been based almost exclusively on their loricae (see Ti. 2 Morphologic outline). The first description of a tintinnid is ascribed to Müller (1786; fide Kofoid and Campbell, 1929), and the first comprehensive monograph on tintinnids was published by Daday (1887b). The studies of Brandt (1906-1907), Laackmann (1907, 1910), Jörgensen (1924) and Kofoid and Campbell (1929, 1939) subsequently provided descriptions and illustrations of over 1,000 species. Kofoid and Campbell's (1929) work established a new classification based on all previous systematic studies. Thus, their revision has been a major reference for virtually all subsequent publications, both taxonomic and ecologic. During the last decades, studies on tintinnids have focused mainly on their abundance in different environments, on their species-specific assemblages as related to currents and water masses, as indicators of environmental settings, and particularly on their functional role in marine trophic chains, (e.g., Souto, 1979; Capriulo and Carpenter, 1980, 1983; Hargraves, 1981; Verity, 1987; Boltovskoy et al., 1989, 1991; Wasik and Mikolajczyk, 1990; 1994; Alder and Boltovskoy, 1991a, b; Barría de Cao, 1992; Boltovskoy and Alder, 1992; Buck et al., 1992; Pierce and Turner, 1992; Garrison and Gowing, 1993).