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Effects of habitat availability on dispersion of a stream cyprinid

Environmental Biology of Fishes

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Abstract

We analyzed temporal changes in the dispersion of the rosyside dace,Clinostomus funduloides, (family Cyprinidae) in a headwater stream, to assess the role of habitat availability in promoting fish aggregation. The dace foraged alone and in groups of up to about 25 individuals, and dispersion varied significantly among monthly censuses conducted from May through December. In two of three study pools, dace aggregated during July, October and/or December, but spread out during other months, especially during September when dispersion did not differ significantly from random. Dispersion was not significantly correlated with the total amount of suitable habitat available to foraging dace, but during summer, corresponded to the availability of depositional areas adjacent to rapid currents. Foragers aggregated in eddies or depositional areas during high stream discharge in July, and shifted out of depositional areas when current velocities declined from July to September. During late autumn, however, aggregations formed independently of changes in habitat conditions, and dace dispersion did not vary significantly among months in a third pool. The study suggests that dace dispersion cannot be predicted from the overall availability of suitable habitat as estimated from point measurements of depth and velocity; both the occurrence of a specific habitat feature (i.e., eddies adjacent to high velocity currents) and seasonal differences in behavior more strongly influenced the spatial distribution of foragers.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of habitat availability on dispersion of a stream cyprinid
Series title:
Environmental Biology of Fishes
Volume
37
Issue:
2
Year Published:
1993
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
121-130
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Biology of Fishes
First page:
121
Last page:
130
Number of Pages:
10