4211

• UCREFRP Catalog Number: 4211
• Author: Ulmer, L.
• Title: Management Plan for the Razorback Sucker ‎(
• USFW Year: 1985.
• Copyright Material: NO

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(Banks 194, Ucacon x.968; Vanic:ek et a1~ 1970; hSiler 172} .
Recent rollectian~~ indicat.c~ nu~m;)ers a~°E> decl~.ninr~ Ewen furthe~r~ and
that populations a..-c comprised of larr~e, presumably old
individ~.TalS, T~~uch a5 in t~1u loE~ae_ ba~:in (see below) . Hol.dvn and
Stalnaker (1975) and t~icAda ~.nd ~dydo.3k i (1930) found razorbacks
scattered thrc~.zghout much of the basin, but concentrated (10 to 25
individuals) in only two places, the Tnoi.ith of t}le Yampa River,
Colorado, and in a Llooded gravel pit (~~alker ~~7ildlife l~r_ea)
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adjacent to the Colorado Rivt~r near Grand Junction, Colorado.
Extensive collections from. Green River (Utah-Colorado) in 1979-31
included only 92 razorbacks, and the species was considered
extreme~:y rare in that system (Tytzs et al. 1932). In the
mainstream Colorado River, razorback was uniformly scarce fro;n
Rifle (Colorado) downstream to Lake Sowell (Utah) during the same
_ years (Valdez et al. 1932x). Two gravel pits near Grarid Junction
(including- Walker [°~ildlife Area) produced 37 of the 52 total.
razorback collected dur..ing that study, while e'> s~aere taken from
backwaters adjacent to the cYtannel, 5 wPr.e from Lake Powell, and
only •~ ~weri~ f:rorEt ~nainstem,riverine ha`~itats. Only one specimeT~
has r<~,cently been reported from the Gunnison l~iiver, Cole)~rado
(Holc.ez., in Valdez et al. 1982b}, ~a}~;L~re the :.pecies once was
commons Jn 1.977, a sma17_ irrig:ztiori reservoix• connected to the
:Ian JUc1T~ R1VC',r (U%-:1}1) ~~7aS e!n~)tied st3'<'nC~1TIt~ 1 ~~) ~ azc)r~)r3Ck (~ ~}1riiZE'
~.nd P}~nic~Ti 193G) . Tire ~.~~;:cics lta~~ n~)~_. t~eEn tick: n in G~yo~ning si;!cc
(.::lo<~z~"E' ~J:," f'l:~!:t3T'1(~ GOr~~E? ??.3lil O1_~ ~:}ltd ~~2:F~F.-~~n ~:].~'~:3?'' ]11 19f).c (~~l<\'t~'.C'
i!1C~ cj1;:C?11 1~i7v e ~r,~;+_-tC(?}Cr'~, cl1 N ~.~71~) ,