The Razorback sucker, an endangered fish native to the Grand Canyon, has been observed spawning. This could mark the return of this threatened species.

Xyrauchen texanus first returned to the area in 2012, after not being seen in the national park since 1990. Larval razorback suckers have now been spotted in nine areas along the lower Colorado River. The discoveries were made by park personnel in April and May 2014.

Razorback suckers were once common throughout the Colorado River and the Green River in Wyoming. They were even found as far away as the Gulf of California.

"The discovery that the Razorback suckers are spawning in the national park far upstream from Lake Mead is good news for this endangered species," Anne Castle, Assistant Secretary for Water and Science, said.

Lake Mead National Recreation Area was the lone habitat for the animal in the wild until these recent finds. A restocking program breeds young razorbacks to repopulate the area, as far away as Utah.

The Colorado River is home to several endangered fish species. Many of these cannot be found anywhere else in the world.

Habitat encroachment and the introduction of invasive species into the area led to the loss of native populations. The Glen Canyon Dam, opened in 1963, reduced the concentration of sediments and the average temperature of the water. These changes radically affected the environment and altered life for the fish.

Researchers use sonic tags implanted inside the fish to track their travels, including recording mating histories. Tracking of the animals had taken place on a regular basis in Lake Meade Recreation center, but that investigation was expanded in spring to include the Grand Canyon.

"This exciting news suggests that Grand Canyon is becoming a significant basin-wide haven for the endangered fishes in the Colorado River," Lesley Fitzpatrick, biologist for the U.S. Fish and Wildlife Service, stated in a press release from the Department of the Interior.

Razorback suckers are the largest species of sucker living in the Colorado River, measuring up to three feet in length when fully-grown. The fish feed on a wide variety of small crustaceans and insects. Members of the species can live to be 40 years old or more. They were placed on the endangered species list in Colorado in 1979 and nationally in 1991.

Biologists are not certain exactly why the razorbacks have started to spawn in the waters of the Grand Canyon. Conditions for spawning have become more favorable for the fish in the last few years. Part of these changes is the result of large-scale man-made floods initiated by the Department of the Interior, beginning in 2012. This program, aimed at rebuilding habitat for marine life, has resulted in the formation of additional sandbars and reefs in stretches of the Colorado River.