9383

• UCREFRP Catalog Number: 9383
• Author: SWCA, I.
• Title: Recovery Goals for the four Colorado River Endangered Fish Species.
• USFW Year: 2000.
• USFW - Doc Type: Logan.
• Copyright Material: NO

3.2 Overutilization for Commercial, Recreational, Scientific, or
ducational Purposes
Overutilization of the endangered fishes for commercial, recreational, scientific, or
educational purposes is not presently considered a threat tothe species. Colorado pikeminnow,
humpback chub, razorback sucker, and bonytail have no current commercial or recreational value
and are not sought by commercial fishermen or sports anglers. All angler access points near
occupied habitat are posted with signs advising anglers to release any endangered fish unharmed.
Collection endangered fishes for scientific or educational purposes is regulated by
lO(a) of the ESA. Scientific collecting permits are issued to
investigators conducting legitimate scientific research. Permits to collect these fish for
educational purposes are normally not requested, but are regulated by the same provisions of the
ESA.
3.3 Disease or Predation
3.3.1

Diseases and Parasites
Diseases and parasites are not to singly contribute to the decline of any of the four
endangered fishes. A survey of diseases 0 endangered fishes in the upper Colorado River Basin
in 1981 (Flagg 1981) revealed that Colorado pikeminnow are infected by two principal parasites
(an intestinal tapeworm and an external parasitic copepod) and the protozoans Myobolus sp. and
Trichodina sp., as well as the trematode Ornithodiplostomum sp. Bass tapeworms
(Proteocephalus ambloplites) were found in 65% of stomachs from fish longer than 200 mm TL
in the Green River (Vanicek 1967). Vanicek (1967) also rep that P. Dotson (unpublished
data, Utah Department ofFish and Game, Salt Lake City, UT
Colorado pikeminnow examined. A cestode identified as Proteocephalus ptychocheilus was
identified from Colorado pikeminnow in the upper basin (Flagg 1982). This may be the same
species reported by Vanicek (1967), but further study has not been conducted to resolve the
taxonomic discrepancy. The Asian tapeworm (Bothriocephalus achielognathii) has been
reported in humpback chub in Grand Canyon (Clarkson et al. 1997, Brouder and H
1997), but not from the other species.
The parasitic copepod (Lernaea cyprinacea) is common in all four species an as been

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