7953

• UCREFRP Catalog Number: 7953
• Author: Miller, W. H., et al.
• Title: Colorado River Fisheries Investigations, 1979 Progress Report - Draft,.
• USFW Year: 1980.
• USFW - Doc Type: ‎(submitted in partial fulfillment of Contract No. 9-07-40l-1016 with the Water and Power Resources Service)‎,
• Copyright Material: NO

Approximately 550 squawfish, lot 4DYAWB, were selected as future broodstock.
Of these, 70 mature males were found to have active sperm in June 1979.
Therefore, the chance of finding a few mature females in 1980 is good.
Of the future broodstock, 150 have been moved from Willow Beach and
Hotchkiss National Fish Hatcheries to the Utah Division of Wildlife
Resources (UDWR) Fisheries Experiment Station in Logan,. Utah; 270 have
gone to Dexter Creek NFH in New Mexico and 130 are still being held at
Willow Beach.
The 918 squawfish lot 9DWB produced at Willow Beach, July 1979 were
transferred to the Fisheries Experiment Station, Logan, Utah in February
1980 for use by Utah State University under their contract.
An attempt to obtain a bonytail male from Lake Mojave by FWS biologists
and others resulted in the capture of five more adult females, but no males.
Two of the females died in the nets before the crew could reach them
while the other three were transferred to the hatchery in good condition.
Fortunately,;eight roundtails (G. robusta) were taken with 19 humpback chubs
from the Colorado River near Grand Junction in November 1979 and are at
the Willow Beach hatchery. They will be used to produce hybrid crosses
with the bonytail chub females.

The Logan Fisheries Experiment Station is scheduled to produce and
culture Colorado squawfish eggs and fish for the Utah State University contract
work. Dexter Creek National Fish Hatchery will rear the hybrids and
other fish that Willow Beach can not handle. There is a possibility
that the squawfish held at Dexter will spawn on their own and become