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Understanding how altered flow regimes mediate interactions among native and nonnative species is necessary for the conservation of aquatic systems. Anthropogenic alteration of natural flows and establishment of nonnative fishes coincided with near extirpation of Colorado pikeminnow (Ptychocheilus lucius) from the San Juan River, NM, USA. Despite major efforts to re-establish this species, recruitment of young individuals into the adult population has not been documented in several decades. A potential reason for apparent recruitment failure is that modified flow regimes and nonnative species have affected reproductive success of native prey, thus limiting potentially critical resources for young (
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Some nonnative fishes have exhibited different feeding behaviors depending on location. In a study within the Colorado River system, Ruppert et al. (1993) found a relatively high occurrence (15%) of larval fish in stomachs of Cyprinella lutrensis. They compared those results to a study by Jennings and Saiki (1990) who found no larval fish in stomachs of C. lutrensis from the San Joaquin River drainage. The disparity between these studies could be a function of site specific characteristics such as availability of alternative food items, or it could be due to specific behavior and vulnerability of prey. The purpose of our study was to determine if nonnative fishes, primarily C. lutrensis and Pimephales promelas,...
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Defining the trophic position of stream organisms is a first step in understanding the ecology of lotic systems. Whereas trophic positions of stream fishes have been traditionally assigned based on dietary analysis, stable isotope ratios may provide additional information on the validity of this approach and may be used to verify energy acquisition assumed from dietary studies. In this study, we assessed the concordance of literature-based trophic classifications and isotopic ?15N signatures for small-bodied fishes from four streams in Kansas, Oklahoma and New Mexico. ANOVA results revealed no significant difference (F2,27 = 1.71, P = 0.201) in trophic position based on ?15N values among three broad trophic classifications...
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1. Data from the literature were used to document colonization patterns by introduced freshwater fishes in 125 drainages across temperate North America. We analysed this data set to quantify susceptibility to invasion, success of the invaders and changes in species richness. 2. Drainages with a high number of impoundments, large basin area and low native species diversity had the greatest number of introduced species. Those drainages containing few native fishes exhibited great variation in the number of invaders, while waters with a rich native fauna contained few introduced species. However, this pattern did not differ significantly from random simulations because the pool of potential invaders is greater for...
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Spatial and temporal variation of fish communities in four secondary channels of the San Juan River between Shiprock, NM and Bluff, UT were investigated from July 1993 through November 1994. Fish abundance and habitat availability data were collected to determine if physical attributes of sites influenced spatial and temporal variation in their fish communities. Stability of habitat was shown to positively influence the stability of the fish community. Analysis of variance revealed greater spatial than temporal variation in the abundance of red shiner, Cyprinella lutrensis, fathead minnow, Pimephales promelas, and flannelmouth sucker Catostomus latipinnis, while speckled dace, Rhinichthys osculus showed greater...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Environmental Biology of Fishes,
american southwest,
assemblage structure,
disturbance,
floods, All tags...
introduced species,
refugia,
stream fish,
stream stability, Fewer tags
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