Midwest Fish & Wildlife Conference 2016

AUTHORS: Thomas E. Dowling*, Department of Biological Sciences, Wayne State University, Detroit MI; Paul C. Marsh, School of Life Sciences, Arizona State University, Tempe AZ and Marsh & Associates; Thomas F. Turner, Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque

ABSTRACT: Advances in molecular genetics have provided new tools for management of endangered fish and wildlife, and these have been especially useful for management of the unique, endemic fishes of the Colorado River basin of the desert Southwest. Human impacts on the basin have resulted in severe reductions in the number and size of populations for most species, and have prompted management actions to protect them. One exemplary species of this fauna is the razorback sucker Xyrauchen texanus, a long-lived, highly fecund catostomid fish. This species was once abundant and distributed throughout the basin, however, loss of available habitat and presence of non-native fishes has led to extirpation of this species from most locations. We have used molecular markers (mitochondrial DNA sequence and microsatellite variation) as a management tool to assess the effect of various management strategies on levels of genetic diversity. Use of large numbers of larvae captured from the wild, raised in protective custody, and repatriated to the lake were found to adequately represent genetic variation in the parental population, validating this as an effective strategy for managing endangered fishes. These markers have also allowed us to assess patterns of reproduction in experimental backwater populations, providing life history information essential for future management actions.