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Topeka shiners (Notropis topeka) were historically abundant throughout many Great Plains streams but their abundance and distribution declined and the species was listed as federally endangered in 1999. However, few studies have examined how Topeka shiner populations are linked to biotic and abiotic factors. Thus, the objectives of this study were to identify trends in Topeka shiner distribution from 1995 to 2008 and determine which fish assemblage and habitat factors were most associated with Topeka shiner distribution in Kansas streams. Fish and in-stream habitat metrics were collected from 34 sites in northeast Kansas in 1995, 2003, and 2008. Stepwise discriminant function analyses (DFA) were used to determine if fish assemblage percent composition and in-stream and landscape habitat factors could be used to differentiate among years and between sites with and without Topeka shiners. Higher percent composition of rosyface shiner (Notropis rubellus) was generally indicative of sites with Topeka shiners ...

Causes for the decline of the federally endangered Topeka shiner (Notropis topeka) are unclear. I used a database of fish community samples in Missouri, dating from 1938 to the present, to investigate spatial and temporal patterns of species occurring within the range of N. topeka. I used what is known about other species associated with N. topeka to provide falsifying evidence for the alternative hypotheses for the decline of N. topeka. Seven species showed a strong decline and four showed a strong expansion over time. Strongly declined species were Ameiurus melas, Carpiodes carpio, Hybognathus placitus, Lepomis humilis, N. topeka, Phenacobius mirabilis, and Pimephales promelas. Strongly expanded species were Fundulus notatus, Lepomis macrochirus, Micropterus salmoides, and Semotilus atromaculatus. Notropis topeka retreated to small, high-gradient streams over time, but this was not a general pattern among other species. In the 1990s, declined species were generally less abundant than expanded s...

We examined gut contents of 65 Topeka shiners (Notropis topeka) collected from the Rock River drainage of southwestern Minnesota in 1997. Anecdotal and unpublished information regarding food habits have suggested that the Topeka shiner is largely a benthic or nektonic insectivore. Our results show that it is an omnivore that feeds opportunistically on immature aquatic insects, several kinds of microcrustaceans and other invertebrates, larval fish, algae, vascular plant matter, and detritus. The Topeka shiner functions both as a benthic and nektonic feeder and shows strong trophic similarities to its sister species, the sand shiner (N. ludibundis).