Comparative ecology of a guild of minnows (Pisces: Cyprinidae) in a southeastern New York stream: Habitat separation, spatial distribution, and feeding ecology

Mary Anne Thiesing, Fordham University

Abstract

The feeding and spatial relationships among members of a guild of Cyprinidae, and particularly the relationships among four species of Notropis, were investigated in the Shawangunk Kill, a second order stream in southeastern New York.^ Data from 1980 and 1981 indicate that four species of Notropis exhibit ontogenetic shifts in habitat preference.^ A new method for food habits analysis is proposed which classifies dietary items on an ecological, rather than taxonomic basis. Discriminant functions analyses of these food categories indicates that the feeding niches of these four species are most distinct in the spring and less distinct in the summer. N. amoenus is a generalist in its feeding strategy and had the greatest within-season variability in its diet; it is probably a surface/midwater feeder. N. cornutus is also capable of using a wide variety of prey, and is likely to be a surface/midwater feeder as well. It, however, switched to completely different major prey types between seasons.^ Both N. spilopterus and N. stramineus had diets which indicate a benthic/epibenthic feeding regime. N. stramineus had the most consistently well-defined diet of the two; N. spilopterus had a slightly more variable diet, but its choice of prey was still indicative of a benthic feeding regime. Between juvenile and adult N. spilopterus, prey size, and not ecological type, is most likely to result in differences in diet.^ Cluster analysis of ecologically classified feeding habits indicates that N. spilopterus and N. stramineus have the greatest overall similarity in diet; N. cornutus and N. amoenus had the greatest similarity with one another in the spring but their diets were too variable in the fall to cause either species to form a coherent group with any other species. It is demonstrated that the ecological classification method, used in a multivariate analysis and analyzed with a taxonomic list of dietary items, provides not only a more rigorous analysis of food habits, but also one which is consistent with the currently accepted model of the niche. (Abstract shortened with permission of author.) ^

Subject Area

Ecology

Recommended Citation

Thiesing, Mary Anne, "Comparative ecology of a guild of minnows (Pisces: Cyprinidae) in a southeastern New York stream: Habitat separation, spatial distribution, and feeding ecology" (1989). ETD Collection for Fordham University. AAI8918646.
http://fordham.bepress.com/dissertations/AAI8918646

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