1108

• UCREFRP Catalog Number: 1108
• Author: Valdez, R. A.
• Title: Fisheries Biology And Rafting Annual Summary Report - 1987
• USFW Year: 1988.
• USFW - Doc Type: ‎(Contract no. 6-CS-40-03980)‎.
• Copyright Material: NO

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and YOY, and the absence of larger fish strongly indicates that these fish are
representatives of the adult portion of the population. A further explanation
of this hypothesis is presented in the 'Chub Biography', submitted as a
supplement to thi s report.

Juveniles. Eleven juvenile humpback chub were handled during the 1987 inves-
tigation (Table 23). These fish were classified as juveniles on the basis of
size relative to the largest fish caught, and on the development of morphologi-
cal characters. Further examination of these in the 'Chub Biography' may
result in reclassification as to stage of maturity or perhaps even species.

Young-Of-The-Year and Larvae. Four YOY humpback chub and no larvae were
handled during this study (Table 24). These fish were all identified by the
LFL The complete series of reports from the LFL, with the observed and
measured diagnostics, is included in Appendix C.

Bony tail

Two fish, tentatively identified as bonytails, were handled during the 1987
Cataract Canyon Fish study (Table 25). One fish was classified as a juvenile
(TL = 264mm, WT = 120g, Red Carlin Tag 5034) and one as an adult (TL = 287mm,
WT = 129g, Red Carlin Tag 5036). Two other possible bony tail (one unconfirmed
adult and one possible YOY) were collected during a similar study in 1985.
Also, a fish captured in 1986 has been tentatively reclassified as an adult
G. elegans, following closer examination of photographs and meristics.
Photographs and further descriptions of these fish are available in the 'Chub
Biography' .

Razorback Sucker

One razorback sucker was handled during the 1987 Cataract Canyon Fish Study
(Table 25). The fish was an adult (TL = 493mm, WT = 1618g, Red Carlin Tag
5029) that was captured, tagged, and released at the large riffle formed at the
mouth of Salt Creek, RM 3.5 on the Colorado River. This fish was captured
September 11, 1987. This razorback is the first one captured during the
investigations of the Cataract Canyon region during 1985, 1986, and 1987.
Prior to this, two adult razorbacks were caught at The Slide (RM 1.4 and 1.5)
in 1981 (Valdez et ale 1982), and six and eleven were caught at Gypsum Canyon
in upper Lake Powell (RM 197.0) in 1980 and 1981, respectively (Persons et ale
1982). The latter investigators also captured two adult razorbacks at Spanish
Bottom (RM 213.0) in 1980.

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