Plains topminnow

Abstract: The plains topminnow Fundulus sciadicus is a freshwater killifish endemic to the Great Plains of North America. Rising concerns for future viability of this species have prompted recent changes in its conservation status. In this study, the results of a range-wide population genetic survey based on the sequence of entire mitochondrial control region (CR) are presented. A total of 181 fish were collected from 11 sites in Nebraska and 10 sites in Missouri spanning the distribution range of the species. Seven polymorphic sites were found in the 966 base pairs of the CR, and only nine unique haplotypes were detected among all fish. Phylogenetic analysis and statistical parsimony networks identified two distinct clades. The first included fish in the Osage, Gasconade and Spring River drainages in Missouri, while the second included individuals from Nebraska and the Lamine River in Missouri, although the Lamine River is much closer to the other Missouri sites than to the Nebraska sites. Pair-wise FST and average population distances indicated that populations from most drainages are genetically distinct, as 93% of the total molecular variance was attributed to among-drainage effects. Four sites within the main distributions of this species and a highly disjunct site from the south-western portion of the range are suggested as potential targets for conservation.

Abstract: We surveyed fish faunas of perennial-warmwater streams of the Cheyenne River drainage, South Dakota, downstream from Angostura Dam and the Belle Fourche Diversion Dam to describe each fish fauna, including the population structure of characteristic fish species, and to summarize broad-scale spatial and temporal trends in fish distributions. We selected our sample stations based on previous data on habitat conditions and fish distributions and sampled five stations monthly from May through October 2004. We determined the characteristic fish species of each sampling station based on five criteria: persistence, dominance, habitat association, population structure, and tagged recaptures. There was much variation in species composition among streams. Of 24 char acteristic species, only stonecat was characteristic of all five stations and only longnose dace was characteristic of four stations. Nine species were characteristic of only one station. This indicates a strong relation between stream type and fish faunal composition. We also documented range contractions of large-river fishes (western silvery minnow, plains minnow, sturgeon chub, flathead chub), which were absent from the Upper Cheyenne River, presumably due to drought and perhaps exacerbated by Angostura Dam upstream. In contrast, plains topminnow and smallmouth bass increased in the Upper Cheyenne River, presumably because they were favored by stable flows. The Cheyenne River drainage down stream from Angostura Dam and the Belle Fourche Diversion Dam in South Dakota has a diverse fish community that is a product of habitat diversity and the absence of physical barriers to dispersal, which allows fishes to respond to changing conditions and locate suitable habitats via dispersal.

Abstract: Salsuginus yutanensis n. sp. (Monogenea: Ancyrocephalidae) is described from the gills of the plains topminnow, Fundulus sciadicus Cope, from Clear Creek in eastern Nebraska. Salsuginus yutanensis is distinguished from previously described species by having a shorter accessory piece and different hamulus proportions, especially in the relative lengths of deep and superficial roots. In addition, the angles between deep and superficial roots distinguish S. yutanensis from several congeners.

Abstract: Fishes were collected in four mainstem reaches and eight tributary reaches in the Keya Paha River basin during May and June 2002. Most reaches were characteristically run habitats with sand substrates and riparian pastures. Data were combined with historical records to construct a basin-wide ichthyofaunal list which comprised 38 species from seven families. Dominant species were sand shiners (Notropis ludibundus; 47%), red shiners (Cyprinella lutrensis; 37%), and brassy minnows (Hybognathus hankinsoni; 8%). Dominant game species were bluegill (Lepomis machrochirus) and channel catfish (Ictalurus punctatus). We found one species previously listed as rare in South Dakota -plains topminnow (Fundulus sciadicus), and four species not previously found in the Keya Paha River—silver chub (Macrhybopsis storeriana), river carpsucker (Carpiodes carpio), northern pike (Esox lucius), yellow perch (Perca flavescens).