Diets of young Colorado squawfish and other small fish in backwaters of the Green River, Colorado and Utah
Citation
Darrel E Snyder, and Robert T Muth, Diets of young Colorado squawfish and other small fish in backwaters of the Green River, Colorado and Utah: .
Summary
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 were important in diets [...]
Summary
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 were important in diets of E lu.cius <21 mm TL and L. cyanellus <31 mm TL. Catostomus discobolus was the only species that ate moderate amounts of algae. Fish (all larvae) were in digestive tracts of only 10 P. lucius (21-73 mm TL), about 1% of P. lucius analyzed. High diet overlap occurred hetween some size-reach groups of P. lucius and c. lutrensi.~, R. os-culus, C. latipinnis, I. putJ.Ctatu~, and L cyanellus. Potential for food competition between youngof- year P. lucius and other fishes in backwaters appeared greatest with the VClY abundant C. lutrensis
Published in Western North American Naturalist, volume 55, issue 2, on pages 95 - 104, in 1995.
