Filters: Tags: Ptychocheilus lucius (X) > Categories: Publication (X)
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ms have reduced distribution of the endangered Colorado pikeminnow Ptychocheilus lucius in the upper Colorado River basin: low-head diversion dams blocked upstream passage and large dams inundated free-flowing segments and cooled downstream reaches with deep-water releases. To date, range restoration efforts in the Colorado and Gunnison Rivers have focused on building fish ladders around diversion dams to allow recolonization of upstream reaches. Upstream thermal suitability for this warmwater cyprinid was assessed using temperature data and existing distributional information from river reaches where Colorado pikeminnow movements were unrestricted. Among-site thermal regime comparisons were made using mean annual...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado River,
Colorado pikeminnow,
Ptychocheilus lucius,
River Research and Applications,
annual thermal units,
Twelve wild adult Colorado pikeminnow (Ptychocheilus lucius), captured in the tailwaters of Taylor Draw Dam on the White River, Colorado, were implanted with radio transmitters and their movement patterns monitored from 1992 to 1994. The spawning migration of these fish was extensive. In 1993, the only full year of the study, the fish migrated an average of 658 km from the White River to spawning sites in the Yampa or Green rivers and back to the White River. Eight of these fish were translocated in the river upstream of the dam in April 1993. These fish and the 4 others below the dam remained in the river until May 1993. All 12 had migrated down the White River to spawning sites in the Green and Yampa rivers by...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado pikeminnow,
Ptychocheilus lucius,
Western North American Naturalist,
home-range fidelity,
migration,
We evaluated the role of major tributary streams for endangered fish recovery using a matrix approach based on quantitative information. However, the need for ranking tributaries for direct and indirect contributions (i.e., assignment of high, medium or low importance) required a more subjective approach. Some streams differed in actual and potential importance because barriers deny fish access to suitable habitat. We have not assigned relative importance to the different types of contributions; to a large extent that may involve policy issues better addressed by the Recovery Program.
Categories: Publication;
Types: Citation;
Tags: Colorado River,
Colorado pikeminnow,
Endangered species recovery,
Gila cypha,
Gila elegans,
Acute toxicity tests were conducted for 96 h with larval Colorado squawfish (Ptychocheilus lucius) and razorback sucker (Xyrauchen texanus) in a reconstituted water quality simulating the San Juan River near Shiprock, New Mexico, to determine biological effect concentrations. Tests were conducted with arsenate, copper, selenate, selenite, zinc, and five mixtures of seven to nine inorganics simulating environmental mixtures reported for sites along the San Juan River (Ojo Amarillo Canyon, Gallegos Canyon, Hogback East Drain, Mancos River, and McElmo Creek). Razorback suckers were significantly more sensitive to arsenate, selenate, selenite, Hogback East Drain mixture, and Ojo Amarillo Canyon mixture than were Colorado...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Environmental Toxicology and Water Quality,
Ptychocheilus lucius,
Xyrauchen texanus,
acute toxicity tests,
hazard assessment,
Alteration of natural flow regimes by river regulation affects fish distribution and assemblage structure, but causative pathways are not always direct and may go unrecognized. The Colorado River population of the endangered Colorado pikeminnow, Ptychocheilus lucius, suffers from low rates of recruitment and reduced carrying capacity. We hypothesized that availability of prey fish for this large-bodied native piscivore may, in part, be limited by reduced standing crops of periphyton and macroinvertebrates resulting from accumulation of fine sediment in the riverbed. We stratified the 373-km-long study area into 11 strata and sampled various physical and biological parameters in runs and riffles of three randomly...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado River,
Colorado pikeminnow,
Ecological Applications,
Ptychocheilus lucius,
benthic macroinvertebrates,
ABSTRACT.-We compared diet of young-or-year Colorado squawfish (Ptychocheilus lucius), an endangered cyprinid, with diets of other fish <75 mm total length (TL) collected from backwaters of the Green River between river kilometers 555 and 35 during summer and autumn 1987. Species included native Rhinichthys osculus, Catostomus discoholus, and C. latipinnis, and nonnative Cyprinella lutrensis, Notrupis stramineus, Pit"l1&'Phales promelas, Ictalurus punctatus, and upamis cyanelll1s. For (;,-8.ch species, diet varied with size and between upper and lower river reaches but not between seasons for Hsh of similar size. Larval chironomids and ccratopogonids were principal foods of most fishes. Copepods and cladocerans...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Cyprinella lutrensis,
Green River,
Ptychocheilus lucius,
Western North American Naturalist,
backwaters,
Evidence for sexual size dimorphism (SSD) and its possible causes were examined in the endangered Colorado pikeminnow Ptychocheilus lucius, a large, piscivorous, cyprinid endemic to the Colorado River system of North America. Individuals representing 18?24% of the upper Colorado River population were captured, measured, sexed and released in 1999 and 2000. Differing male and female total length-(LT) frequency distributions revealed SSD with females having greater mean and maximum sizes than males. Although both sexes exhibit indeterminate post-maturity growth, growth trajectories differed. The point of trajectory divergence was not established, but slowed male growth might coincide with the onset of maturation....
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado pikeminnow,
Journal of Fish Biology,
Ptychocheilus lucius,
age at first reproduction,
growth rate,
The completion in the fall of 1984 of Taylor Draw Dam on the White River, Colorado, formed Kenney Reservoir — thus impounding the last significant free-flowing tributary in the Upper Colorado River Basin. Fishes were sampled above and below the dam axis prior to closure of the dam and in the reservoir and river downstream following impoundment. While immediate effects of the dam to the ichthyofauna included blockage of upstream migration to 80 km of documented range for endangered Colorado squawfish, the reservoir also proved to have profound delayed effects on the river''s species composition. Pre-impoundment investigations in 1983–1984 showed strong domination by native species above, within, and below the...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Catostomus,
Centrarchidae,
Colorado River Basin,
Cyprinidae,
Environmental Biology of Fishes,
Growth and survival of Colorado squawfish, Ptychocheilus lucius, larvae under fluctuating 18, 22, and 26 degrees C (5 degrees C diel fluctuations) and constant 18, 22, 26 degrees C, and 30 degrees C temperature conditions and ration size corresponding to 12.5, 28, 64,142, 320 brine shrimp nauplii fish(-1) day(-1) was determined from laboratory experiments. Growth was optimal at 31 degrees C and high at temperatures of 26 degrees C to 30 degrees C, at the highest food abundance. Lowest growth was under lowest food rations and highest temperatures. Growth of Colorado squawfish larvae declined substantially at temperatures < 22 degrees C. Neither growth nor survival was significantly different between fluctuating or...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado River,
Cyprinidae,
Environmental Biology of fishes,
Ptychocheilus lucius,
critical period,
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