7040

• UCREFRP Catalog Number: 7040
• Author: Miller, R. R.
• Title: Man and the Changing Fish Fauna of the American Southwest
• USFW Year: 1961
• USFW - Doc Type: Papers of the Michigan Academy of Science, Arts, and Letters
• Copyright Material: YES

-?? PIP,

07,040
PAPM OF THE MICHraAN Acwsmy of SmNcs, ABrs, AND LLras
VoL. XLVI, 1961 (1960 MnTzNa)
MAN AND THE CHANGING FISH FAUNA OF
THE AMERICAN SOUTHWEST,
ROBERT RUSH MILLER
Museum of Zoology, The University of Michigan

.,.
T?Hz past 100 years have witnessed drastic changes in the rivers of
western North America and in their fish faunas. Deterioration of
stream flow has greatly shrunk the ranges of many species, and other
species have been denied access to large segments of their original
distribution by the construction of barrier dams. Profound modifica-
tion of pristine environments has restricted habitable waters, and the
introduction and establishment of a host of exotics have brought
about replacement as well as reduction of native forms through com-
petition, predation, and hybridization. Some species and subspecies
have become extinct, and many others are endangered (Matthiessen,
1959). These changes have been particularly marked in areas of re-
stricted water supply such as characterize the and Southwest (Fig.
1). Much of this region is embraced by the Basin and Range Province
(Fenneman, 1931, pl. I), including the Great Basin, Sonoran Desert,
and the Chihuahuan Desert of northern Mexico.
Only about 100 species of strictly fresh-water fishes are known
west of the Rocky Mountains and north of Mexico-a depauperate
fauna characterized by relicts, monotypic genera, and much regional
'The initial version of this paper was presented at the Fifth Annual Sym-
posium on Systematics, Missouri Botanical Garden, St. Louis, on October 25,
1958, under the general subject "Taxonomic Consequences of Man's Activities."
Field work has been generously supported by the Horace H. Rackham School
of Graduate Studies and the Museum of Zoology, University of Michigan.
Space prohibits naming the many ranchers, old-timers, colleagues, and officials
to whom I am deeply indebted for historical testimony and other assistance.
Credit to some of these people is given in the text. Permits to collect in
Arizona, California, Nevada, New Mexico, Texas, and Utah were kindly ar-
ranged by the authorities of, those states. The map (Fig. 1) was lettered by W. L.
Brudon.
The following museum abbreviations are used: CAS, California Academy of
Sciences; MCZ, Museum of Comparative Zoology, Harvard College; SU, Stan-
ford University Natural History Museum; UMMZ, University of Michigan
Museum of Zoology; and USNM, United States National Museum.
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