GCDAMP RAZU Fish

Razorback sucker (Xyrauchen texanus) Three to 5 million years ago, a unique-looking fish with a sharp-edged hump “razorback” behind its head swam the Colorado River and its tributaries. The razorback sucker is an endangered, native fish of the Colorado River and the only member of the genus Xyrauchen. It has a dark, brownish-green upper body with a yellow to white-colored belly and an abrupt, bony hump on its back shaped like an upside-down boat keel. One of the largest suckers in North America, the razorback sucker can grow to 3 feet in length and can live for more than 40 years. Razorback sucker can reproduce at 3 to 4 years of age. Depending on water temperature, spawning can occur as early as November or as late as June. In the Upper Colorado River Basin razorback sucker typically spawn between mid-April and mid-June. Razorback sucker eat insects, plankton, and plant matter on the bottom of the river. To complete its life cycle, the razorback sucker moves between adult, spawning, and nursery habitats. Spawning occurs during high spring flows when razorback sucker migrate to cobble bars to lay their eggs. Larvae drift from the spawning areas and enter backwaters or floodplain wetlands that provide a nursery environment with quiet, warm, and shallow water. Research shows that young razorback sucker can remain in floodplain wetlands where they grow to adult size. As they mature, razorback sucker leave the wetlands in search of deep eddies and backwaters where they remain relatively sedentary, staying mostly in quiet water near the shore. In the spring, razorback sucker return to the spawning bar, often quite a long distance away, to begin the life cycle again.[1] Razorback suckers in Grand Canyon The razorback sucker was thought to be extirpated, or locally extinct, from Grand Canyon until 2012 when several adult razorback suckers were captured in the western Grand Canyon during surveying work. Prior to these occurrences, razorback suckers were last found in Grand Canyon more than 20 years ago. Recently, they have been found spawning in the Colorado River inflow at the upper end of Lake Mead. The National Park Service is currently planning studies to determine the status of the species in Grand Canyon. Prior to the constructions of dams on the Colorado River and other human-caused alternations to their habitat, razorback suckers were widely distributed in the Colorado River and its major tributaries, and were typically found in calm flat-water reaches. There are at least ten historical records of razorback suckers caught in Grand Canyon, including a specimen caught in Bright Angel Creek in 1944. Today, the largest population, and possibly only population of wild reproducing razorback suckers, is in Lake Mead. The species was listed as endangered in 1991. Critical habitat, including all of Grand Canyon National Park, for the species was determined in 1994.[2]

Online training	Fish Species of the Colorado River in Lower Glen Canyon and Grand Canyon	Fish photos, information, and maps

Updates Status and distribution Listed as endangered and given full protection under the Endangered Species Act in 1991. Endangered under Colorado law since 1979. Protected under Utah law since 1973 Historically, the razorback sucker was widespread and abundant in the Colorado River and its tributaries. Today all populations of razorback sucker are supplemented with stocked fish except for the Lake Mead population. Lakes Mead and Mohave are the only population with wild fish.[3] Working to recover the species Actions being taken to recover the razorback sucker include: Managing water to provide adequate instream flows to create beneficial water flow Constructing fish passages and screens at major diversion dams to provide endangered fish with access to hundreds of miles of critical habitat Restoring floodplain habitat Monitoring fish population numbers Managing nonnative fishes In addition, the Recovery Program works to reestablish naturally self-sustaining populations of razorback sucker through propagation and stocking. The Recovery Program maximizes the genetic diversity of wild broodstock used to produce fish in hatcheries to increase the likelihood that stocked fish can cope with local habitats. In the Upper Colorado River Basin, razorback sucker are raised at two units of the Ouray National Fish Hatchery: the Grand Valley Unit in Grand Junction, Colorado, and the Ouray Unit in Vernal, Utah. Razorback sucker raised at these facilities are stocked in the Colorado, Green, and Gunnison rivers. Efforts to reestablish populations through stocking demonstrate success as stocked fish survive to sexual maturity and reproduce. Fish stocked in the Colorado and Green rivers have been recaptured in reproductive condition and often in spawning groups. Captures of larvae in the Green and Gunnison rivers document reproduction and their survival through the first year is evidenced by subsequent captures of juveniles. Stocked fish are moving between the Green, Colorado, and Gunnison rivers. This exchange of individuals between rivers suggests that razorback sucker may eventually form a network of populations or subpopulations.[4] Recovery goals Razorback sucker will be considered eligible for downlisting from “endangered” to “threatened” and for removal from Endangered Species Act protection (delisting) when all of the following conditions are met: Self-sustaining fish populations reach the required numbers in areas of the Green River subbasin and EITHER the Colorado River subbasin or San Juan Rivers, and the Lower Colorado River Basin, and a genetic refuge is maintained in Lake Mojave as identified in the chart below. The threat of significant “fragmentation” of the population has been removed. (Fragmentation refers to separation between fish populations caused by geographical distance or physical barriers.) Essential habitats, including primary migration routes and required stream flows are legally protected. Other identifiable threats that could significantly affect the population are removed. Downlisting Criteria Over a 5-year monitoring period: Maintain reestablished populations in Green River subbasin and EITHER in upper Colorado River subbasin or in San Juan River, each > 5,800 adults Maintain established genetic refuge* of adults in Lake Mohave Maintain two reestablished populations in lower basin, each > 5,800 adults Delisting Criteria For 3 years beyond downlisting: Maintain populations in Green River subbasin and EITHER in upper Colorado River subbasin or in San Juan River, each > 5,800 adults Maintain genetic* refuge of adults in Lake Mohave Maintain two populations in lower basin, each > 5,800 adults [5]

Links Upper Colorado River Endangered Fish Recovery Program San Juan River Basin Recovery Implementation Program Lower Colorado River Multi-Species Conservation Program Native Fish Lab of Marsh & Associates LLC Documents 2018 Razorback Sucker Species Status Assessment 2018 Razorback Sucker 5-Year Review 2012 Razorback Sucker 5-Year Review 2002 Razorback Sucker Recovery Goals 1998 Razorback Sucker Recovery Plan Reports and Publications 2023 Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada 2023 FINAL ANNUAL REPORT 2022 HIGHLIGHTS OF: Assessment of Potential Augmentation and Management Strategies for Razorback Sucker Xyrauchen texanusin Lake Mead and Grand Canyon: A 2021 Science Panel Summary Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada 2022 FINAL ANNUAL REPORT 2021 Long-Term Experimental and Management Plan Biological Opinion Conservation Measures Update 2019 Razorback Sucker SSA and 5-year Review Presentation Proposed Downlisting of the Humpback Chub and Razorback Sucker Update 2018 Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada 2018 FINAL ANNUAL REPORT Razorback & Flannelmouth Sucker Hybridization Razorback Sucker Xyrauchen texanus research and monitoring in the Colorado River inflow area of Lake Mead and Grand Canyon, Arizona and Nevada PPT Albrecht et al., 2018, Use of inflow areas in two Colorado River basin reservoirs by the endangered razorback sucker (Xyrauchen texanus), Western North American Naturalist 2017 Conservation Status of the Razorback Sucker in the Colorado River Basin BioWest-Razorback Sucker 2017 Final Report Kegerries et al. 2017. Occurrence and Reproduction by Razorback Sucker (Xyrauchen texanus) in the Grand Canyon, Arizona. Southwest Naturalist. Three-Year Review of Razorback Sucker Xyrauchen texanus Research in Grand Canyon and Colorado River Inflow to Lake Mead: A Science Panel Report MONTHLY PROGRESS REPORT August 2017: Razorback Sucker Research & Monitoring Work - Lower Grand Canyon & Colorado River MONTHLY PROGRESS REPORT July 2017: Razorback Sucker Research & Monitoring Work - Lower Grand Canyon & Colorado River Razorback Sucker Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon Increased Upstream Detection of Larval Razorback Sucker, Colorado River in Grand Canyon, 2016 2015 2015 FINAL ANNUAL REPORT: Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada Razorback Sucker in Lower Grand Canyon and the Lake Mead Inflow Area--A History of the Species and Biological Opinions Razorback Sucker Monitoring and Research in Lower Grand Canyon and the Colorado River Inflow Area of Lake Mead Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada 2014 New Information on Razorback Sucker in Western Grand Canyon and Lake Powell New Information on Razorback Sucker in Western Grand Canyon Native Fish Population Trends – Grand Canyon Tributaries Razorback Sucker: Status and Habitat Use (Healy) 2012 Recovery Planning for the Razorback Sucker and Bonytail in the Lower Colorado River Basin The Potential of Habitat for the Razorback Sucker in the Lower Grand Canyon Report and PPT Strategy for Establishing the Razorback Sucker in the Lower Grand Canyon and Lake Mead Inflow Report Review and Summary of Razorback Sucker Habitat in the Colorado River System Report Razorback Sucker in Lake Mead, Lake Powell and Lower Grand Canyon - What's New and What's Next PPT 2009 The Razorback Sucker: Back from the Brink 2007 and 2008 Conservation Measures and Conservation Measures Razorback Sucker PPT 2007 and 2008 Biological Opinions Conservation Measures Update Conservation Measures Razorback Sucker PPT LTEMP BiOp Conservation Measures for Razorback Sucker [6] (2016) Ongoing actions: Reclamation would continue to assist the NPS, FWS, and the GCDAMP in funding larval and small-bodied fish monitoring in order to: Determine the extent of hybridization in flannelmouth and razorback sucker collected in the western Grand Canyon. Determine habitat use and distribution of different life stages of razorback sucker to assist in future management of flows that may help conserve the species. Sensitive habitats to flow fluctuations could be identified and prioritized for monitoring. Assess the effects of TMFs and other dam operations on razorback sucker. Other Stuff Endangered fish, razorback sucker spawning Razorback Sucker Underwater Footage Audio Script Larvae collected as far upstream as Havasu Creek [7] Radio-tagged adult migrated upstream from Diamond Creek to just below Bright Angel Creek (2016) [8] High Country News: Canyon’s depths—but will the razorback sucker stick around? AZ Daily News: Razorback Sucker turns up in Grand Canyon after 20 years The last one recorded had been caught in 1990. Caught October 9th, lower part of Grand Canyon believed to have traveled upstream some 50 miles from Lake Mead.