8171

• UCREFRP Catalog Number: 8171
• Author: U.S. Fish and Wildlife Service.
• Title: A Study to Determine the Biological Feasibility of Pit Tags for Endangered Fishes in the Upper Colorado River Basin.
• USFW Year: 1990.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

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vinyl paint, and hinged-plywood lids were installed. Fish were provided with a constant
supply of ground water at a constant temperature of about 15 C. Mechanical demand
feeders were installed on the tank lids prior to the arrival of the fish. Fish were fed
commercially-prepared dry trout pellets (size No. 4) and naturally-grown amphipods
(Gammarus spp.) that were transferred from grow-out ponds at the hatchery. Tanks
were cleaned regularly by hatchery personnel. The water supply and tanks were isolated
from the salmonid fishes reared at the hatchery. Fish were allowed 2 weeks to acclimate
before PIT tag implantation.
In Grand Junction, squawfish were held in vinyl-coated stock tanks (capacity: 570 L)
with recirculating water. Water temperature ranged from 20-27 C. Fish were fed dry
trout pellets (No. 4).
Ta in
For this study, we chose two anatomical sites for PIT-tag implantation--the body
cavity and dorsal musculature. The placement of the PIT tag in the body cavity and
dorsal musculature was determined from studies performed on Pacific salmon (Prentice
et al. 1985), and from our determination that these anatomical sites would be the best
areas of placement from both a biological and technical standpoint. Limited
experimentation was conducted in 1986 with adult roundtail chub to allow workers
experience with injecting PIT tags, to determine appropriate anatomical sites for
injecting the tags, and to evaluate the placement and tissue response of the internal
organs and body musculature to the tag.
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