9411

• UCREFRP Catalog Number: 9411
• Author: Williamson, J. H., D. C. Morizot and G. J. Carmichael.
• Title: Biochemical Genetics of Endangered Colorado Pikeminoow from the Green, Yampa, Colorado, and San Juan Rivers.
• USFW Year: 1998.
• USFW - Doc Type: \
• Copyright Material: NO

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GR*b, TPI-L *a, and TPI-2*a alleles into breeding populations. Maintenance of separate brood fish
populations insures availability of fish for stocking should one population suffer catastrophic loses.
Although we recognize the difficulty of accomplishing this task, it does not exclude use of individuals
lacking these rare alleles. Lack of individual fish and genetic variability within the San Juan River
Colorado pikeminnow population contraindicates development of a separate hatchery population from the
this source; should stocking be an appropriate recovery strategy, reintroduction into the San Juan River
should be from offspring of the Colorado River and/or Green River broodfishes. Any fish used for
reintroduction should be the result of controlled reproduction of selected individuals (Williamson and
Wydowski 1994).
We recommend that the Colorado/Green DX-FI(81) population and derived populations be
replaced with separate Green River and Colorado River broodfish populations for use in the upper basin.
We recommend that strict and stringent pedigree breeding strategies and genetic management programs be
developed and records be maintained of hatchery and management actions. The most productive future
sampling and identification of new polymorphic loci should involve increases in sample sizes of YOY from
middle reaches of the Green River and middle and upper Colorado River. Doubling of sample sizes of
YOY from those currently analyzed would provide critical tests of genetic differentiation within and
between watersheds, and identify with more certainty alleles found in a single river basin. Sampling of
non-lethal tissues, including liver biopsies from broodstock adults, would facilitate inclusion of uncommon
alleles in filial generations and insure their availability in selected individuals for reintroduction founders.
The total of 15 polymorphic loci in the species guarantees high. preselected heterozygosity in broodfish
founders, following either a population- or maximum heterozygosity-(individually based)-selection criterion
for inclusion into hatchery or refugium populations.