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<br />New Mexico. San Juan Countv: and Utaho San Juan Countv. The San Juan
<br />River from the State Route 371 Bridge in T. 29 N., R. 13 W., section 17
<br />to Neskahai Canyon up to the full pool elevation in the San Juan arm of
<br />Lake Powell in T. 41 S., R. 11 L, section 26.
<br />
<br />RAZORBACK SUCKER
<br />
<br />Historical and Current Distribution
<br />
<br />The razorback sucker, an endemic species unique to the Colorado River Basin,
<br />was historically abundant and widely distributed within warmwater reaches
<br />throughout the Colorado River Basin. Historically, razorbacks were found in
<br />the main stem Colorado River and major tributaries in Arizona, California,
<br />Colorado, Nevada, New Mexico, Utah, Wyoming, and in Mexico (Ellis 1914;
<br />Minckley 1973). Bestgen (1990) reported that this species was once so
<br />numerous that it was commonly used as food by early settlers, and further,
<br />that commereially marketable quantities were caught in Arizona as recently as
<br />1949. In the Upper Basin, razorback suckers were reported in the Green River
<br />to be very abundant near Green River, Utah, in the late 1800's (Jordan 1891).
<br />An account in Osmundson and Kaeding (1989) reported that residents living
<br />along the Colorado River near Clifton, Colorado, observed several thousand
<br />razorback suckers during spring runoff in the 1930's and early 1940's. In the
<br />San Juan River drainage, Platania and Young (1989) relayed historical accounts
<br />of razorback suckers ascending the Animas River to Durango, Colorado, around
<br />the turn of the century. Platania and Young (1989) also reported the 1976
<br />capture of two adult razorback suckers by VTN Consolidated, Inc., from an
<br />irrigation pond adjacent to the San Juan River near Bluff, Utah.
<br />
<br />In August 1990, the New Mexico Department of Game and Fish (Lief Ahlm, NMGF,
<br />pers. comm.) interviewed two anglers from Aztec, New Mexico, who claimed to
<br />have "commonly" caught razorback suckers in the Animas River near Cedar Hill
<br />bridge in the 1930's and 1940's. When the two men were shown a battery of
<br />photographs, including roundtail chub (Gila robusta), humpback chub (Gila
<br />~), bony tail (Gila eleaans), bluehead sucker (Pantosteus discobolus),
<br />flannelmouth sucker (Catostomus latiDinis), razorback sucker, and Colorado
<br />squawfish, they both immediately identified the razorback sucker as the fish
<br />they had caught. However, prior to the 1976 capture by VTN Consolidated,
<br />Inc., there were no scientifically verified reports of razorback sucker
<br />captures in the San Juan River drainage.
<br />
<br />The current distribution and abundance of razorback sucker has been
<br />significantly reduced throughout the Colorado River system (McAda 1987; McAda
<br />and Wydoski 1980; Holden and Stalnaker 1975; Minckley 1983; Marsh and Minckley
<br />1989; Tyus 1987). The only substantial population of razorback suckers
<br />remaining, made up entirely of old adults (McCarthy and Minckley 1987), is
<br />found in lake Mohave; however, they do not appear to be successfully
<br />recruiting. While limited numbers of razorback sucker persist in other
<br />locations in the lower Colorado River, they are considered rare or incidental
<br />and may be continuing to decline.
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