title: Competition and coexistance between Glossiphonia complanata and Helobdella stagnalis (Glossiphoniidae: Hirudinoidea).
abstract: The prey utilization of Glossiphonia complanata and Helobdella stagnalis from Bruce Lake, Alberta, Canada was examined quantitatively using serological techniques. While considerable prey range overlap occurred between the species, niche overlap was low during the winter, peaked in March and declined through the summer. Temporal differences in feeding and intraspecific weight class differences in prey utilization were found in both species but more distinctly in G. complanata. It is suggested that co-existance of G. complanata and H. stagnalis is based on adjustments of weight class food resource partitioning on a temporal basis.
authors.affiliation: Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada.
authors.forename: F J
authors.initials: FJ
authors.lastname: Wrona
authors.affiliation: Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada.
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Davies
authors.affiliation: Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Linton
authors.affiliation: Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada.|Zaklad Biologii, Wydzial Matematyczno-Pryzyrodniczy, Filii Universitytetu Warszarskiego, w Bialymstoku, 41 Lipowa Street, 15-424, Bialystok, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Wilkialis