Effects of Substrate Embeddedness on Behavior of the Gilt Darter (Percina evides)
Author(s)
Sutherland, Andrew B.
Advisor(s)
Editor(s)
Hatcher, Kathryn J.
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Abstract
We investigated the general behavior of
the gilt darter (Percina evides Jordan and Copeland), a
benthic fish whose distribution has been shrinking
since the early part of this century. Direct
observations (by snorkeling) were made in Fall 1999
in five streams that differed in sedimentation,
measured as substrate embeddedness. Embeddedness
varied from 40% - 70%. Ten fish were observed per
stream, each for 15 minutes. Observations focused on
foraging, swimming, and resting as well as number of
feeding strikes. Time spent foraging, swimming, and
resting was significantly different (p < 0.001) among
sites, as was number of feeding strikes per observation
period. We also found a marginally significant (p =
0.08) relationship between foraging time and mean
substrate embeddedness. Number of feeding strikes
versus embeddedness was also marginally significant
(p = 0.06). Swimming and resting time were not
correlated with embeddedness. Mean number of
feeding strikes was significantly correlated with mean
foraging time (p = 0.03). This study suggests that
increasing embeddedness may affect the activity of
this relatively silt-tolerant darter, implying that less
tolerant benthic taxa may be more heavily influenced
by increasing streambed sedimentation.
Sponsor
Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of Technology
Date
2001-03
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Resource Type
Text
Resource Subtype
Proceedings