Ecology of Bonytail and Razorback Sucker and the Role of Off-Channel Habitats in Their Recovery Scientific Investigations Report 2006-5065 U.S. Department of the Interior U.S. Geological Survey Ecology of Bonytail and Razorback Sucker and the Role of Off-Channel Habitats in Their Recovery By Gordon A. Mueller In cooperation with the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and Arizona State University. Scientific Investigations Report 2006–5065 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior P. Lynn Scarlett, Acting Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia: 2006 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report Suggested citation: Mueller, G.A., 2006, Ecology of bonytail and razorback sucker and the role of off-channel habitats in their recovery: U.S. Geological Survey Scientific Investigations Report 2006-5065, 64 p. Contents iii Contents Abstract ..........................................................................................................................................................1 Chapter 1. The Fish ........................................................................................................................................2 Overview ................................................................................................................................................2 Current Status of Bonytail and Razorback Sucker ..........................................................................2 Status of the Bonytail ..................................................................................................................2 Status of the Razorback Sucker ...............................................................................................4 Propagation and Stocking ...................................................................................................................4 Stocking Programs and Relative Success .......................................................................................6 Central Arizona .............................................................................................................................6 Senator Wash, California ...........................................................................................................6 Lake Mohave ................................................................................................................................6 Lake Havasu .................................................................................................................................6 Lower Colorado River (Downstream of Parker Dam) ............................................................8 Upper Colorado River ..................................................................................................................8 San Juan River .............................................................................................................................8 Prognosis ...............................................................................................................................................8 Study Objectives ...................................................................................................................................8 Ecology of Bonytail and Razorback Sucker .....................................................................................9 Capture Techniques ....................................................................................................................9 Bonytail ................................................................................................................................9 Larvae ........................................................................................................................9 Larger Bonytail ...........................................................................................................9 Razorback Sucker .............................................................................................................10 Larvae ......................................................................................................................10 Larger Razorback Suckers .....................................................................................10 Mortality Issues ...............................................................................................................12 Bonytail Life History ..................................................................................................................13 Physical Description .......................................................................................................13 Distribution and Abundance ..........................................................................................14 Diet ...............................................................................................................................14 Parasites ............................................................................................................................16 Age-Length Distribution ...................................................................................................16 Longevity ...........................................................................................................................16 Habitats and Habits .........................................................................................................17 Beaver Association .................................................................................................17 Movement .........................................................................................................................17 Reproduction .....................................................................................................................18 Spawning Site Selection .......................................................................................18 Spawning Behavior ................................................................................................19 General Behavior .............................................................................................................19 Fry and Juveniles (<10 cm) ....................................................................................20 Adults (>10 cm) ........................................................................................................20 iv Ecology of Bonytail and Razorback Sucker Razorback Sucker Life History ................................................................................................20 Physical Description .......................................................................................................21 Sexual Dimorphism ..........................................................................................................21 Distribution and Abundance ...........................................................................................22 Historic Distribution ................................................................................................22 Beginning of the End: 1880–1970 ..........................................................................22 1970 to Present ........................................................................................................22 Razorback Sucker Young ................................................................................................24 Diet ...............................................................................................................................24 Parasites ............................................................................................................................25 Age Determination ............................................................................................................26 Age-Length Distribution ..................................................................................................26 Longevity ............................................................................................................................27 Habitats and Habits ..........................................................................................................27 Movement .........................................................................................................................27 Reproduction ....................................................................................................................28 River Spawning .......................................................................................................29 Reservoir/Pond Spawning .....................................................................................31 Recruitment .............................................................................................................31 General Behavior ..............................................................................................................32