7406

• UCREFRP Catalog Number: 7406
• Author: Bestgen, K. R.
• Title: Status Review of the Razorback Sucker,
• USFW Year: 1990.
• Copyright Material: NO

including the razorback sucker, is largely unknown. The
occurrence of rare fishes in the San Juan River was reviewed by
Platania (1990) and Platania et aI. (in press). Early records
indicated that razorback suckers and other "large-river forms"
(including Colorado squawfish) "ran" up the Animas River near
Durango, Colorado (Jordan 1891). However, these were based on
undocumented evidence; Holden (1980) did not list any collection
localities for the razorback sucker in the San Juan River
drainage, and Tyus et al. (1982) listed a single locality,
presumably from the San Juan River arm of Lake Powell. The only
other San Juan River sub-basin records were those of Smith
(1959), who reported two small (3.75 cm) razorback suckers from
the Colorado River in Glen Canyon prior to inundation by Lake
Powell.
There are no specimen-substantiated records for the
razorback sucker in the San Juan or Animas rivers in New Mexico
or Colorado, although local fishermen accurately described fish
similar to razorback suckers (Koster 1960). If razorback suckers
existed in the San Juan River, New Mexico, construction and
operation of Navajo Reservoir may have reduced their numbers. No
razorback suckers were observed in the extensive pre-impoundment
"fish kill associated with closure of the reservoir (Olsen 1962),
indicating that razorback suckers may not have occurred in that
area.
Fishery surveys of the San Juan River following closure of
Navajo Reservoir (Sublette 1977, VTN Consolidated 1978, Minckley
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