Comparative Swimming Performance of Five Catostomus Species and Roundtail Chub

Abstract

Abstract.—Decreased habitat connectivity and competition with nonnative species have led to declines of many freshwater fishes. An understanding of swimming performance can aid in the conservation of these fishes; however, acquiring sufficient numbers of rare and threatened species to perform swimming studies can be logistically challenging and ecologically costly. In order to determine whether swimming data for common sucker species may be substituted for that of similar but rare sucker species, we compared the swimming abilities of two rare western catostomids, Bluehead Sucker Catostomus discobolus and Flannelmouth Sucker C. latipinnis, as well as one catostomid with a less well understood status, Mountain Sucker C. platyrhynchus, with those of the common White Sucker C. commersonii and Longnose Sucker C. catostomus. We also examined Roundtail Chub Gila robusta because they are often included in conservation efforts involving Bluehead Sucker and Flannelmouth Sucker. The critical swimming velocities (U_crit), standardized by body length, of Bluehead Sucker and Longnose Sucker differed significantly from those of White Sucker. However, there was no significant difference between the U_crit of Mountain Sucker, Flannelmouth Sucker, and White Sucker. During constant acceleration trials, Bluehead Sucker exhibited the greatest swimming ability, reaching a mean maximum velocity of 4.56 ± 1.28 body lengths per second (BL/s; mean ± SD), followed by Mountain Sucker (3.56 ± 0.57 BL/s), White Sucker (3.28 ± 0.90 BL/s), Longnose Sucker (2.97 ± 0.31 BL/s), and Flannelmouth Sucker (2.22 ± 0.42 BL/s). Additionally, key behavioral differences in the swimming behaviors of the fishes studied were observed. We conclude that swimming performance data for common White Sucker should not be used in place of data for rarer species. Comprehensive swimming studies should be conducted on individual sucker species before implementing conservation strategies involving fish passageways or barriers.

Received November 6, 2013; accepted February 28, 2014

ACKNOWLEDGMENTS

This research was supported by the U.S. Department of the Interior Bureau of Reclamation (contract number L11AC20378). All fish use was carried out under the conditions set by Colorado State University Institutional Animal Care and Use Protocol 11-3026A. We thank H. Bergman, A. Walters, and the University of Wyoming for providing us with access to the Red Buttes Environmental Biology and Ecology Laboratory, and J. Bobbit and S. Devries of the RBEBL for their technical assistance. We thank the Wyoming Game and Fish Department for providing us with access to and information on the fish we used, P. Lionberger for his support of the project, and H. Meador for fish care. Additional technical assistance was provided by A. Ficke, E. Gardunio, and other members of the Colorado State University Fish Physiological Ecology Laboratory.