Some factors effecting algal consumption in subarctic ephemeroptera, plecoptera and simuliidae
✍ Scribed by J. W. Moore
- Book ID
- 104733122
- Publisher
- Springer-Verlag
- Year
- 1977
- Tongue
- English
- Weight
- 733 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0029-8549
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✦ Synopsis
Some of the factors influencing algal consumption in the mayflies Leptophlebia nebulosa, Cinygrnula tarda, Baetis foernina and B. cf. bicaudatus, the plecopterans Arcynopteryx signata, Nernoura cinctipes and N. oregonensis and in the dipterans Sirnuliurn arcticurn, S. venusturn and S. decorum were investigated between June 1975 and June 1976 in several streams in the Canadian subarctic. Algae represented up to 65% of the gut contents of L. nebulosa but only 0-8% in the other mayflies. They were important in the plecopterans (85-90%) but less so (2-13%) in the simuliids. Most of the interspecies variability in algal consumption could be explained in terms of food availability. This factor was in turn dependent on the density and attachment characteristics of the flora and the strength of their cell wall. Feeding intensity in most species was low between October and April, reaching its peak in July and August. From 51 to 83% of intraspecies feeding variability was due to changing temperature, followed in importance by water velocity in the dipterans and food availability in the mayflies. All species in this latter group ceased feeding in the final instar stages.