The Razorback Sucker Xyrauchen texanus is a sucker which belongs to the family catastomidae. It is found in the Colorado River in only a handful of places, but used to be found extensively in the Colorado River Basin in the U.S. and Mexico. It can grow to 91 cm (3 ft) in length and is defined by the keel "razor" between its head and dorsal fin. Razorbacks feed on algae, insect larvae, and detritus. In the shallows, males stake out a spawning territory and hover near it. Razorback suckers are long-lived fishes and have been estimated at more than 40 years of age. Both males and females mature at age four. Spawning occurs in late winter or spring when groups of razorbacks settle to the riverbed and release their gametes. The adhesive eggs become attached to the interstitial spaces in the gravel substrate. A single female is attended by two to twelve males, and the female will spawn repeatedly with several males.
The Razorback Sucker has been listed as an endangered fish species by the Endangered Species Act since 1991. The two primary reasons for the species demise is habitat destruction in the form of dams such as the Hoover, Davis, and Glen Canyon to name a few as well as invasive, exotic, non-native fish species. Dams block routes to ancient spawning grounds, isolate populations, change riverine habitats to reserviors, change warm waters to year-round cold water, prohibit ancient flooding patterns neccessary for reproduc tion and larval growth, and flood backwaters and nursery habitats for young Razorback Sucker. Invasive fish species predate upon Razorback Sucker and their young which kills populations and prohibits the recruitment of reproducing adults. Invasive fish predators include Striped Bass Morone saxatilis, Flathead Catfish, Green Sunfish, and several others.
Current conservation programs include the raising of larval Razorback Sucker by a collaborative approach of the United States Fish & Wildlife Service, the United States Bureau of Reclamation, Marsh & Associates, LLC, etc. Razorback Sucker are captured as larvae in Lake Mohave, delivered to the Willow Beach National Fish Hatchery, and raised until adults. They are then repatriated into Lake Mohave. The method of this conservation is to limit predation on larvae and juveniles as adult Razorback Sucker are less likely to be predated upon by invasive fish predators other than Striped Bass.
Razorback suckers are long-lived fishes and have been estimated at more than 40 years of age. Both males and females mature at age four. Spawning occurs in late winter or spring when groups of razorbacks settle to the riverbed and release their gametes. The adhesive eggs become attached to the interstitial spaces in the gravel substrate. A single female is attended by two to twelve males, and the female will spawn repeatedly with several males.
Razorbacks feed on algae, insect larvae, and detritus. In the shallows, males stake out a spawning territory and hover near it.
In 2021, the Fish and Wildlife Service proposed to reclassify the razorback sucker as threatened under the ESA despite that they have not met the requirments to be downlisted.
1.5 Hours of Razorback Sucker Underwater