Collection of age-0 razorback suckers (Xyrauchen texanus) in the lower Green River, Utah

Citation

Gutermuth, F Brandt, Lentsch, Leo D, and Bestgen, Kevin R, Collection of age-0 razorback suckers (Xyrauchen texanus) in the lower Green River, Utah: .

Summary

Historically widespread and abundant throughout warm water reaches of the Colorado River basin, the endemic razorback sucker (Xyrauchen texanus) is now rare and listed as endangered (United States Fish and Wildlife Service, 1991). Mainstem dams that alter habitat and introduction of non-native fishes which prey upon or compete with early life stages are among the large-scale ecological disturbances that have negatively affected the razorback sucker (Tyus, 1987; Minckley et al., 1991). Rarity of larval and especially juvenile razorback suckers in collections, and presence of only aged adults in remaining populations indicates recruitment failure (McCarthy and Minkley, 1987; Lanigan and Tyus, 1989; Minckley et al., 1991). Adult razorback [...]

Summary

Historically widespread and abundant throughout warm water reaches of the Colorado River basin, the endemic razorback sucker (Xyrauchen texanus) is now rare and listed as endangered (United States Fish and Wildlife Service, 1991). Mainstem dams that alter habitat and introduction of non-native fishes which prey upon or compete with early life stages are among the large-scale ecological disturbances that have negatively affected the razorback sucker (Tyus, 1987; Minckley et al., 1991). Rarity of larval and especially juvenile razorback suckers in collections, and presence of only aged adults in remaining populations indicates recruitment failure (McCarthy and Minkley, 1987; Lanigan and Tyus, 1989; Minckley et al., 1991). Adult razorback suckers are abundant only in Lake Mohave in the lower Colorado River basin (Minkley, 1983; Minckley et al., 1991), and the largest remaining riverine population is in the upper Green River, near Jensen, Utah (Lanigan and Tyus, 1989; Tyus and Karp, 1990; Minckley et al., 1991). In Lake Mohave, razorback suckers spawn annually and produce large numbers of larvae, but juvenile recruitment has been rare since the 1950s (Marsh and Minckley, 1989; Minckley et al., 1991). Juvenile razorback suckers were historically rare in collections from the Colorado River basin, and most juveniles caught since 1980 were collected from canals and ponds downstream of Lake Havasu and Parker dam in the lower Colorado River (Minckley et al., 1991). In the Green River, near Jensen, Utah, ripe razorback suckers annually congregate over gravel bars, but prior to this record, the only recent evidence of successful reproduction was limited to a 1984 collection series of larvae tentatively identified as razorback suckers by D. E. Snyder (Tyus, 1987; Tyus and Karp, 1990). Although Holden (1980) reported capture, in 1977, of two approximately 50-mm juvenile razorback suckers from below the confluence of the White and Green rivers, further analysis of these specimens (e.g., low gill raker and high lateral line counts) by other researchers suggests that they were more likely razorback x flannelmouth sucker (Catostomus latipinnis) hybrids (P. Holden, pers. comm.). Unfortunately, these specimens have been lost and were not analyzed. Thus, only two substantiated collections of razorback sucker juveniles have been made in the Upper Colorado River basin. Smith (1959) reported two young razorback suckers, each about 38 mm total length (TL), from a pre-impoundment Lake Powell survey of the Colorado River in Glen Canyon, and Taba et al. (1965) reported eight specimens (90 to 115 mm TL) from backwaters of the Colorado River downstream of Moab, Utah, during surveys in 1962 to 1964. Published in The Southwestern Naturalist, volume 39, issue 4, on pages 389 - 391, in 1994.

Contacts

Author :: Gutermuth, F Brandt, Lentsch, Leo D, Bestgen, Kevin R

Related External Resources

Type: Web Link

Web Link	http://www.jstor.org/stable/30054380

note	Notes
tableOfContents	Table of Contents
citationType	Mendeley

Collection of age-0 razorback suckers (Xyrauchen texanus) in the lower Green River, Utah

Citation

Summary

Summary

Contacts

Communities

Tags

Provenance

Additional Information

Identifiers

Citation Extension

Item Actions

View Item as ...

Save Item as ...

View Item...