the Humpback Chub population (Valdez etal. But that could change soon, a … These isolated refuges may contain The humpback chub is an Endangered, native species of the Colorado River that evolved around 3.5 million years ago. The largest known population of humpback chub is in the Lower Colorado River (LCR) Basin in the Grand Canyon -- primarily in the LCR and its confluence with the main stem of the Little Colorado River. Year Published: 2016 Survival, growth, and movement of subadult humpback chub, Gila cypha, in the Little Colorado River, Arizona. The Little Colorado River aggregation is the only known spawning population of humpback chub in Grand Canyon. Humpback chub require water temperatures of at least 61º F to spawn. The humpback chub, a native fish that calls the Colorado River Basin home, went on the endangered species list in 1967. In a feasibility study of the establishment of a second spawning population in Grand Canyon, Valdez et al. Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life …
SIZE: The common length for the Humpback chub is 25 cm (9.8 in) with the maximum reported length being 38 cm (15 in). The humpback chub was listed as endangered species by the U.S. Humpback chub does not does not currently carry a special state designation in California. Fish and Wildlife Service on March 11, 1967.

2013). Humpback chub is currently classified as a “wildlife species of concern” in Arizona. RANGE: Humpback chub are found in the Little Colorado River. Humpback chub were listed as endangered in Arizona in 1969. Officials are focused on controlling the nonnative fish population and relocating humpback chub into other tributaries with suitable habitat to help maintain and grow the overall chub population. In 2009, the U.S. Geological Survey announced that this population increased by about 50 …

2000). However, these smaller tributaries, some of which are iso-lated from the Colorado River by barriers to fish move-ment, may not support large populations of Humpback Chub, potentially leading to a low probability of establish-ment (Pine etal. The largest population of humpback chub, over 12,000 fish in the Grand Canyon and Little Colorado River, has remained stable over the last 10 years.