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Predator–prey interactions between Dugesia gonocephala and free‐living nematodes
Author(s) -
Beier S.,
Bolley M.,
Traunspurger W.
Publication year - 2004
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1046/j.1365-2426.2003.01168.x
Subject(s) - microcosm , biology , juvenile , predation , predator , nematode , functional response , ecology , zoology
Summary 1. Three groups of laboratory experiments clarified the role of nematodes as a potential food resource for the triclad Dugesia gonocephala . The first group measured the functional response of adult D. gonocephala feeding on juvenile or adult Caenorhabditis elegans . The feeding rates of D. gonocephala on adult and juvenile C. elegans followed a type II functional response. The maximum number of adult nematodes and juvenile nematodes eaten by a single D. gonocephala individual within 3 h was 94 and 197 nematodes, respectively. 2. A second group of microcosm experiments investigated the effect of D. gonocephala on the density and the vertical distribution of a nematode community in fine sand. The following treatments were performed: (i) microcosms with 400 nematodes and (ii) microcosms with 400 nematodes and one D. gonocephala . After 5 days, nematodes as a group, as well as the dominant species Tobrilus pellucidus and Trischistoma monohystera , showed no significant difference in vertical patterns between the treatments with and without D. gonocephala . 3. The third group of experiments determined whether grain size of the sediment (sand, fine gravel and coarse gravel) altered the ability of D. gonocephala to consume adult C. elegans . Sand and fine gravel reduced the predation effectiveness of D. gonocephala by 100%, whereas the predator consumed nematodes in coarse gravel (19 nematodes within 3 h).