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DISCUSSION <br />Nematoda <br />The role of free living nematodes in aquatic systems has not been extensively <br />studied. However, aquatic nematodes are known to be microbotrophic, predaceous, and <br />and or parasitic during one or more of their life stages (Poinar 1991). Due to the <br />scarcity of adequate keys and their small size, nematodes are not enumerated or listed <br />beyond the phylum designation in most studies. In studies of aquatic systems where <br />nematodes are grouped as one taxa', the highest densities have been found in lakes. <br />Strayer (1985) and Nalepa and Quigley (1983) reported that nematodes comprised 60% <br />and 80% respectively of all benthic metazoans in Mirror Lake and Lake Michigan with <br />a means of 680,000/m2 (Mirror lake) and 260,000/m2 (Lake Michigan). In contrast, <br />Palmer in Goose Creek (1990) and Gladden and Smock (1990) on the floodplain of <br />Colliers Creek reported that nematodes comprised a much smaller percentage (6% of <br />total invertebrates) and occurred at diminished densities (1,000 - 15,000/m2 and 1746/m2 <br />respectively) in lotic systems. <br />In our study, nematode density estimates from the seasonally inundated wetland <br />June sample and river channel July and August samples ranged from 2,421 - 24,881/m2. <br />These densities are comparable to densities previously reported from lotic systems <br />(Palmer 1990 and Gadden and Smock 1990). Density estimates for all other sites and <br />dates (54,872 - 302,603/m2) are more similar to densities in lentic habitats. This may <br />be due to the more stable environment provided by calmer waters and smaller sediment <br />size in the various habitats. In their study of White Clay Creek, Bott and Kaplan (1989) <br />13