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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anonymous single-copy nuclear DNA techniques. This purpose followed previous (FY91, #24; FY92,
425) but similar proposals to describe biochemical genetic analyses of Mendelian polymorphisms.
The broad goal of this investigation is to provide genetic information required to more effectively
recover and manage the Colorado pikeminnow. Additional genetic data are required to allow more accurate
population identification and characterization. Determination of variability is needed for fish throughout
the present geographical range. In combination with ecological, distributional, morphological,
demographic, and behavioral data, genetic conservation or management units need to be identified by
examination of genetic structure within and among populations, river tributaries, and river basins. A
standardized and centralized database of genetic markers to use in planning, monitoring, and evaluating
management actions such as founding genetic refugia, production of broodfish populations, and fish
production and stocking will assist Colorado pikeminnow management efforts. Genetic hazards, such as
excessive inbreeding and/or outbreeding associated with various management strategies and actions, need
to be identified. Hypotheses of chemoreception, migration, and homing and assumptions associated with
various management actions also need to be examined.
Objectives included determinations of whether or not there is genetic differentiation within the
species and, if so, the genetic relationships among populations. This task included measuring the amount
and pattern of genetic variation within and among populations, or purported populations; defined as genetic
structure. Hypotheses tested were Ho: Colorado pikeminnow are genetically homogeneous or panmictic
and Ha: genetically differentiated populations of Colorado pikeminnow exist. Specific objectives to be
addressed include: 1) Genetic identification and characterization of the species; 2) Definition of genetic
profiles for management units; 3) Determination of genetic status of management units; 4) Identification of
genetic markers for management purposes; 5) Generation of genetic data required to develop breeding
strategies and broodfish populations; and 6) Production of a management document with recommendations.
We also intended to investigate an additional genetic method examining genomic DNA and develop
nonlethal and economical methods of genetic analyses. Some specific tasks in the present study were: 1) to
detect genetic variability within and among indigenous and captive Colorado pikeminnow spawning
populations; 2) to examine the feasibility of locating or detecting genomic DNA variability within and
among Colorado pikeminnow spawning populations; 3) to estimate allozyme allele frequencies in adult and
young-of-the-year populations associated with known spawning areas; 4) to further evaluate and maximize
the use of non-lethal tissues to obtain genetic information; and 5) to consider the management implications
of our findings.
Methods
Samples from throughout the presently recognized range of Colorado pikeminnow were obtained
from the upper mainstem Colorado River, Yampa River, Green River, and San Juan River by personnel
from the U. S. Fish and Wildlife Service, Colorado Department of Wildlife, New Mexico Game and Fish
Department, Utah Department of Natural Resources, and BioWest Incorporated (Logan UT). Hatchery
broodfish populations were sampled from Dexter NFH&TC. One broodfish population was derived from
Yampa River fish (Yampa River DX-F, (74)) and the other from Colorado/Green River fish
(Colorado/Green DX-F, (81)). For histories of these hatchery fish see Ammerman and Morizot (1989) and
Appendix I, Table 1.). We also re-examined the data from fish sampled by Ammerman and Morizot
(1989) (Colorado/Green River DX-F,(81) and Yampa River DX-F2(87)). Another population maintained
at Dexter NFH&TC (Yampa River DX-F2(91)) was sampled. A recent addition to the populations at
Dexter NFH&TC, one consisting of 10 wild fish captured from the Colorado River, was also sampled
(Colorado DX-F0 (91). Populations and sampling locations were selected by biologists for the Upper
Colorado River Recovery Implementation Program as locales where adult and young-of-the-year Colorado
pikeminnow feasibly could be collected in association with spawning. Sample sizes, locations of fish
collected or sampled, and populations sampled are presented in Appendix I (Tables 2 and 3). Adult and
juvenile fish were collected by using trammel nets and electroshocking from 1990 through 1993 and tissue
samples were obtained non-lethally. For purposes of this study, juveniles were defined by field biologists.
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