7001

• UCREFRP Catalog Number: 7001
• Author: Wydoski, R. S., et al.
• Title: Editor
• USFW Year: Series
• USFW - Doc Type: 1976
• Copyright Material: NO

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6. Andreasen, J. K. 1973. Reproductive life history of Catostomus
ardens and Catostomus discobolus in the Weber River, Utah.
M. S. Thesis, B~igham Young Univ., Provo. 31 pp.

DESCRIPTION, FISH, LIFE HISTORY

Although this study involved fish from outside of the Colorado
River, one species (Catostomus discobolus) is also found in the
Colorado River Basin. 'The yearly reproductive cycle for these two
fish was followed by a histoiogical study of the testes and
measurements of oocyte diameters. A monthly gonadal index was
calculated for each sex and species. Spawning in 1972 occurred
'during maximum water temperature.

7. Andreasen, J. K.,and J. R. Barnes. 1975. Reproductivelife
history of Catostomus ardens and~. discobolus in the Weber
River, Utah. Copeia 1975(4): 645-648.

FISH, LIFE HISTORY

The yearly reproductive cycle in C~tostomus ardens and C. discobolus
was studied by means of gonad indices, histological sections of the
testes and measurements of oocyte diameters. Spermatocytes prolif-
erated rapidly following spawning and spermatozoa ove~nter in the
lobules of the testes. Recruitmentoocytes(<.45 mm) are present
in the ovary the entire year. The largestoocytes gradually
increase in size until they are spawned during May to July in
~. discobolus and during mid-May to J~ne in C.. ardens. Spawning
in 1972 occurred in a period of maximum water temperature. The
gonad index data correlated well with the stages of development of
the testes and with increasing oocyte diameter.

8. Andrews, A. K. 1970. The distribution and life history of the
fathead minnow (Pimephales promelas Rafinesque) in Colorado.
Ph. D. Thesis, Colorado State Univ., Fort Collins. 141 pp.

ABUNDANCE, AGE-GROWTH, ECOLOGY, FISH, FOOD HABITS, LIFE HISTORY,
MOVEMENT, POPULATION, SURVEY

Thorough description of the distribution and life history of the
fathead minnow in Colorado including habitat preference and relative
abundance. Includes collections from the Colorado River Basin.

9. Anonymous. 1969. Water pollution studies: study of the effects
of mineral mining and milling operations on high mountain streams.
Colorado Dept. Game, Fish, Parks, Denver. Progr. Rep., Fed. Aid
Proj. F-33-R-4~ Job 1.

MINERAL, POLLUTION, RIVER-Dolores, SanMiguel, WATER QUALITY

Includes water analysis for sodium, potassium, calcium, lead, iron,
molybdenum, magnesium, manganese, and copper as ~ell as stream
bottom samples from the Dolores and San Miguel Rivers. This was a
co~tinuingstudy and other reports are 'available under Federal Aid
Project F-33-R.