The Effects of Odonates on a Littoral Prey Community

Date of Graduation

Summer 1992

Degree

Master of Science in Biology

Department

Biology

Committee Chair

John Havel

Abstract

Lestes sp. and Anax sp. are the dominant larval odonates of MIller's Marsh, Beaver Island, Michigan. These opportunistic predators cling to littoral vegetation and consume aquatic insects and microcrustaceans. To monitor the effects of these odonate predators on community dynamics, a 2X2 factorial in situ enclosure experiment was set up and monitored over an eight-week period. Twelve enclosures were placed in a littoral area of MIllers's Marsh, each containing a natural prey community and absence or presence of dragonfly or damselfly larvae. Prey organisms were sampled with duplicated samples once a week. Statistical analyses indicated a lack of significant predator effects on both the the density and population dynamics of prey whereas replicated enclosures accounted for most of the variation in prey densities. Possible explanations for these results include insufficient replication, odonate mortality, or the accidental presence of other invertebrate predators.

Subject Categories

Biology

Copyright

© Frederick E Dry

Citation-only

Dissertation/Thesis

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