8165

• UCREFRP Catalog Number: 8165
• Author: Czapla, T. E.
• Title: Genetics Management Plan ‎(Revised)‎.
• USFW Year: 1999.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

Humpback Chub
Yampa River Stock
1. The morphometnc and genetic information should be available m March, 1999. Humpback chubs
collected from the Yampa River exhibit great variation in the nuchal hump and may be hybridizing
with roundtail chubs. Conduct Gila genetics workshop in 1999 to determine the risk of hybridization.
The Service needs to accept potential hybridization and determine how hybrids count towazd
endangered species status, interim management objectives and recovery goals.
2. Determine population size estimate and its relation to interim management objectives for this stock.
D
l
i
G
C
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eso
at
on-
ray
anyon Stoc
1. The morphometric and genetic information should be cazefiilly reviewed when available in March,
1999. Humpback chubs collected from the Desolation-Gray Canyon reach of the Green River
exhibit great variation in the nuchal hump and maybe hybridizing with roundtail chubs. Conduct
Gila genetics workshop 1999 to determine the risk of hybridization. The Service needs to accept
potential hybridization and determine how hybrids count toward endangered species status, interim
management objectives and recovery goals.
2. Determine population size estimate and its relation to interim management objectives for this stock.
Black Rocks Stock
1. In September 1996, 15 humpback chub were collected from Black Rocks Canyon and held in
Horsethief ponds. During the summer of 1997, these fish were all lost, at least some due to coyote
predation. Prior to the demise of the adult humpback chubs in Horsethief ponds, a spawn occurred
resulting in 90 young of year in captivity. These fish should grown in captivity for another year and
released back to Black Rocks Canyon in the fall of 1999.
2. Continue to monitor this humpback chub stock using standardized sampling methods (McAda et al.
1994) to follow the status and trend of the stock. Detemvne population size estimate and its relation
to interim management objectives for this stock.
3. Conduct Gila genetics workshop in 1999 to determine the risk of hybridization. The Service needs to
accept potential hybridization and determine how hybrids count towazd endangered species status,
management objectives and recovery goals.
Westwater Canyon
1. Continue to monitor this humpback chub stock using standazdized sampling methods (McAda et al.
1994) to follow the status and trend of this stock. Detemune population size estimate and its relation
to interim management objectives for this stock.
2. Determine if upstream movement of humpback chubs from Westwater Canyon to Black Rocks
Canyon is occurring from the large number of tagged fish in Westwater.
3. Conduct Gila genetics workshop in 1999 to determine the risk of hybridization. The Service needs to
accept potential hybridization and detemvne how hybrids count towazd endangered species status,
management objectives and recovery goals.
Cataract Can
on Stock
y
1. Conduct Gila genetics workshop in 1999 to determine the risk of hybridization. The Service needs to
accept potential hybridization and determine how hybrids count toward endangered species status,
management objectives and recovery goals.
2. Determine if bonytail stocked in the Professor Valley reach are moving into the Cataract Canyon
reach and possibly hybridizing with the humpback chub stock.
3. Determine population size estimate and its relation to interim management objectives for this stock.

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