A Dwindling Resource of the Desert Southwest

This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. ~ United States W,}l D epartment of Native Fishes of Arid Lands: ~ Agriculture Forest Service A Dwindling Resource Rocky Mountain of the Desert Southwest Forest and Range Experiment Station Fort Collins, Colorado 80526 General Technical Report RM-206 Rinne, J ohn N.; Minckley, W. L. 1991. Native fishes of arid lands: a dwindling resource of the desert Southwest. Gen. Tech. Rep. RM-206. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 45 p. Includes color photos of 44 species of fishes, many published fo r the first time. Text describes aquatic systems in the mountains and deserts of the Southwest, the unique fishes they support, and habitats the fishes need. Front cover: Roundtail chub. Back cover: Aravaipa Creek, one of the best examples of native fish habitat remaining in Arizona. l USDA Forest Service General Technical Report RM-206 September 1991 Native Fishes of Arid Lands: A D-windling Resource of the Desert South-west Photographs by John N. Rinne Rocky Mountain Forest and Range Experiment Station 1 Tempe, Arizona Text by W. L. Minckley Arizona State University Tempe, Arizona 1Headquiuters in Fort Collins, Colorado, in cooperation with Colorado State University. The Bureau of Reclamation, USDI, helped finance the printing of this publication. Preface The goal is to advertise these unique, threatened and endangered fishes, and try to increase public Native freshwater fishes of the desert Southwest awareness of their plight. Knowledge of how these are disappearing. Fishes obviously require water, animals look and live, along with general information scarce in the past in this vast arid zone, and even on their status, may contribute to their perpetuation. more so now with burgeoning human populations. A list of technical literature on fishes of the region, As a result, this relatively small, special group of their basic biology, and the imperiled status of the animals has fallen on hard times. entire aquatic fauna is provided as Appendix I. Native freshwater fishes have received little Use of terms that refer to the conservation status attention from resource managers, or for that matter of various species follows that of the International the public, simply because they tend to be unfamil Committee on Endangered Species of the American iar. Most people do not recognize the differences Fisheries Society. "Endangered" fishes are those in between different species of fishes, or even that danger of extinction throughout all or a significant different species of certain groups exist. Common portion of their ranges. "Threatened" species are names are confusing in fishes, since the term likely to be endangered within the foreseeable future. "minnow" means a little fish to almost anyone, and Fishes of "special concern" may become threatened "sucker" is often used in a derogatory sense, or endangered by minor disturbances, or those which referring to a species that feeds on other than require additional information to determine their ''healthy'·· foods accumulated on the bottom. status. Scientific names are not included in text or Actually, both minnows and suckers are each figure captions in an attempt to make the separate families, the Cyprinidae and Catostomidae, presentation more readable. Both common and that make up a large proportion of the fishes native scientific names of fishes mentioned in text are to western North America. Some minnows get big, provided in Appendix II. and most suckers feed on live foods such as algae and mayflies, just like other stream fishes. Recognizing the problems of unfamiliarity and Acknowledgments difficulties of identification, Rinne began to accumulate photographs of native fishes in the Permits for collecting, photographing, and 1970s. Efforts included development of a special otherwise dealing with native western fishes were chamber where fish could be kept alive and well granted by the States of Arizona, Nevada, and New during photography, and emphasis was on natural Mexico, and for threatened and endangered species, colors of living individuals, to illustrate how these by the U.S. Fish and Wildlife Service. Work in animals actually look in nature. Photographs were Mexico was under permits issued through the chosen to illustrate not only their various body courtesy of the Mexican government. The Defenders shapes, but also their functional features such as of Wildlife and Nature Conservancy were especially breeding color and morphologic variation-some of helpful in allowing access to the Aravaipa Canyon the more dynamic aspects of their existence. As Preserve. Uncredited photographs were taken permitted by other assignments, he traveled to specifically for this work. Photographs provided by obtain photographs throughout southwestern United others-B. D. DeMarais, S. G. Fisher, D. A. and]. States and northwestern Mexico. Acceptable R. Hendrickson, B. L. Jensen,]. E. Johnson, W. G. photographs accumulated slowly. Some were Kepner, G. C. Kobetich, G. Mueller, R. D. Ohmart, published elsewhere to further other research efforts; R. Todd, and the U.S. Bureau of Reclamation-are others appear here for the first time. The present credited in the figure captions; Figure 63 is report includes photographs of 46 species of fishes, reproduced by permission from Arizona Game and some of the places in which they live, and of some Fish Department. Forest Service personnel who past and present conditions of regional aquatic provided able and substantial assistance with the habitats. project included Marty Jakie and Scott Belfit. Many The text by Minckley draws upon his experience others helped, and all are due our thanks. of mor~ than 30 years of research on desert aquatic The text was originally prepared while Minckley systems and fishes. It emphasizes historic aspects of was on an Interagency Personnel Agreement Act rivers and springs in the West-where they are, appointment between the U.S. Fish and Wildlife when they formed, and how they work. Treatments Service and Arizona State University. B. L. Jensen of fishes include comments on life-history traits, and his staff at Dexter National Fish Hatchery, species uniqueness, and historic and present values, Dexter, New Mexico, provided assistance, support, along with their roles in natural aquatic and encouragement that contributed substantially to communities. the final product. Contents Page Preface ................................................. Acknowledgments ........................................ Introduction . 1 The Setting . -. 1 Origins of the Desertlands . 1 Water, Aquatic Habitats, and the Impacts of Humans . 2 Natural Aquatic Habitats and Native Fishes . 6 Creeks in the Pines . 6 High Mountain Trouts . 7 Other Species .........................-. 10 Streams at Intermediate Elevations . 11 An Historic Perspective . 11 Ecology of Present Systems . 13 Fishes of Intermediate Elevations . 14 Low Desert Streams . 2 7 Low Desert, Riverine Fish Communities . 29 Marine Species . 36 Fishes of Desert Oases . 3 7 Discussion and Conclusions . 39 Appendix I. Selected References . 41 Appendix II. Common and Scientific Names . 43 1.17" 115° 31° PACIFIC OCEAN KEY 0 City ; Reservoir tfJ Ory Lake ~ Estuarine Marsh 1 Njolural Lake ,,. 113° Figure 1 . The region termed the American Southwest encompasses parts or all of the Mexican states of Baja California Norte, Baja California Sur, Chihuahua, Coahuila, and Sonora, and Arizona, California, Colorado, Texas, New Mexico, Nevada, and Utah in the United States. Native Fishes tn Arid Lands: A Dwindling Resource of the Desert Southwest Photographs by John N. Rinne Text by W. L. Minckley INTRODUCTION THE SETTING The American Southwest is usually defined to Elevations in the region vary from sea level to include all or part of 12 States in western United more than 3600 m. Precipitation is equally variable, States and Mexico (Fig. 1), much of which is averaging less than 5. 0 em per year in the most lowland desert interrupted and diversified by isolated severe desert, to more than 128 em at the higher mountains and plateaus. Evaporation exceeds elevations. Most of the vegetation zones of North precipitation so greatly that surface water should the America are represented, from patches of tundra on oretically not exist. Nonetheless, major rivers such as the highest peaks, downhill through extensive conifer the Colorado and Yaqui formerly collected sufficient forests then woodlands and grasslands, to end with water to flow all the way through the arid lowlands desertscrub on the basin floors. to the sea. The region is also hydrologically complex. Most Just a few decades ago, western streams swarmed major drainage basins are composites ·of once with fishes that had survived millennia of remarkable independent systems brought together by dustal geologic and climatic changes. They had adapted to movements or volcanic activity. Most of the Sonoran survive the special conditions in canyon-bound rivers Desert region, emphasized here, is characterized by that varied from raging torrents in flood to isolated through-flowing rivers passing from mount~i!J.S to the pools in drought. Some had specialized to withstand sea. Closed basins (Fig. 2), from which wat:r' escapes high summer temperatures and salts concentrated by only through evaporation or seepage, are common in evaporation in desert lakes and marshes. However,

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