Date of Graduation
1997
Document Type
Thesis
Abstract
The darter fauna in the Elk River, West Virginia, is extremely diverse (18 species); however, few studies exist on its ecology. This dissertation, which consists of three manuscripts, provides data on the ecology of darters within the Elk River. In the first manuscript, I estimated allozyme variation in the Tippecanoe (Etheostoma tippecanoe) and golden (Etheostoma denoncourti) darters, fishes with extremely fragmented distributions. Despite our findings of low variation at 22 loci, frequency differences at Pgm and Pgdh separated E. tippecanoe and E. denoncourti. The second manuscript is a study of microhabitat use and partitioning in ten darter species. While snorkeling, I marked the locations of darters on the stream bed, and recorded the position of each darter relative to the substrate (under, between, or on top of rocks), depth, water velocity, and substrate type. I used canonical discriminant analysis as a descriptive approach to determine which habitat variables were important in segregating species. Habitat partitioning was associated with position relative to the substrate, depth, water velocity, and substrate type. Microhabitat use for species (based on depth and substrate) often differed among sites of different habitat availability, but was more consistent for water velocity and the position relative to the substrate. These results indicate that microhabitat variables associated with behavior, such as positioning relative to the substrate, can be important in habitat partitioning among darters. In the third manuscript, I examined the influence of spatial scale (sampling area) on estimates of substrate use in seven benthic darter species. The size of substrate used by darters was estimated at three spatial scales (25 x 25 cm, 15 x 15 cm, and 5 x 5 cm sampling areas). Indices of substrate use in darters differed when calculated at slightly different spatial scales. The effect of spatial scale on indices of substrate use was influenced by substrate heterogeneity and the position of darters relative to the substrate. In microhabitat studies, substrate use should be examined across several spatial scales (particularly in fishes that occur in heterogeneous habitat), because estimates of substrate use are affected by small changes in spatial scale.
Recommended Citation
Welsh, Stuart Andrew, "The ecology of darters in the Elk River, West Virginia." (1997). Graduate Theses, Dissertations, and Problem Reports. 10002.
https://researchrepository.wvu.edu/etd/10002