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

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Pedigree Analyses: Methods of pedigree analysis in order to keep track of coatings, progeny and crosses in
following generations is needed to maximize the genetic diversity. This will aid in determining crosses
among F, broodstock to develop production numbers in the future.
A. Razorback sucker. The razorback sucker was considered to be priority "1" among the four
endangered fish species because all stocks are declining rapidly and little or no recruitment has been
documented. All stocks were assigned a "Priority 1" designation since all stocks maybe important in the
recovery effort. In addition, some wild stocks in the upper basin (e.g., middle Green River) contain
sufficient adult fish so that this species has a high potential for recovery. The development of two
broodstocks of razorback suckers was begun in 1993 as an "insurance policy" to prevent immediate
extinction of this species from the wild in the upper basin.
1. Middle Green/Yampa River (Razorback-Jensen Barl Stock. In 1995, the Program switched
from the 5x5 diallele cross to the 25x25 paired coatings strategy to develop 25 F, future broodstock.
Currently the Ouray National Fish Hatchery is holding 20 F,'s family lots; 7 of these are appropriate for the
25 single paired coatings, the others are now excess and need to be distributed according to the disposition
policy. A total of 18 males and 18 females are needed to complete the 25x25 paired coatings, 7 of each sex
(14 total) are being held at Grand Valley Endangered Fish Facility. In the spring of 1998, a concerted
effort is being organized to collect the other 11 of each sex, spawn them stream side and maintain the
family lots at Wahweap State and Ouray National hatcheries.
2. Lower Green River Stock. In 1997, one adult and two larval razorback sucker were collected
near the San Rafael River and several larvae in the area of Lake Powell inflow. In 1998, two possible adult
razorback sucker and flannelmouth sucker hybrids were collected by electrofishing and 35 larvae in light
traps (80% of samples processed) near the confluence of the San Rafael River. Razorback sucker in the
lower Green River should be genetically compared to those throughout the Upper Basin. Fish should be
secured in refugia and broodstock development should be initiated.
2. Upper Colorado River Stock. Seventeen wild caught razorback sucker have been used in a
5x5 diallele cross to produce 32 family lots. The current breeding matrix at the Grand Valley endangered
Fish Facility is using the 5x5 diallele cross. This should be expanded to utilize the 25x25 coatings and 25
family lots strategy to reduce the risk of inbreeding. The 25x25 paired coatings should be developed as soon
as possible to meet upcoming production needs in restoration stocking. In the summer of 1997, 11 (6 male:5
female sex ratio) adult razorback suckers were transferred from Ouray National Fish Hatchery to the Grand
Valley Endangered Fish FacilitylHorsethief Ponds. The Ouray facility had limited success in 1997 in
spawning these fish. In the spring of 1998, attempts will again. be made to spawn these fish at Grand Valley.
If spawning is successful at Grand Valley, the majority of these progeny should be returned to Ouray to meet
broodstock and family lot development needs in the middle Green River. These progeny should be
transported at the earliest life stage possible, but with minimum risk in mortality. A minimum number should
be kept at Grand Valley for broodstock development needs in the Colorado River. To further meet the
broodstock development need, adult Lake Mohave razorback suckers and/or their sperm should be used to
complete the 25x25 paired coatings.
B. Bon ' . The bonytail was assigned "Priority 2" among the four endangered fishes because this
species is nearly extirpated from the upper basin and the possibility of using upper basin bonytails for
broodstock development is very remote. The Biology Committee participants agree that broodstock
development of the bonytail for future restoration stocking will be done using the Lake Mohave stock that
is maintained at Dexter National Fish Hatchery in New Mexico.
1. Lake Mohave Stock. New broodstock development is continuing with 25 paired coatings
of bonytail at Dexter. The Program should maintain a working relationship where Dexter National Fish
Hatchery maintains and develops broodstock and early life stages for grow out in the upper basin facilities.
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