English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The humpback chub (Gila cypha) is a freshwater fi sh that may live as long as 40 years and is found only in the Colorado River Basin. Habitat alterations, including changes caused by dams and reservoirs and the introduction of a wide variety of nonnative fi sh, have contributed to population declines that caused the humpback chub to be placed on the Federal list of endangered species in 1967. Only six populations of humpback chub are currently known to exist, fi ve above Lees Ferry, Arizona, and one in Grand Canyon, Arizona. The U.S. Geological Survey’s (USGS) Grand Canyon Monitoring and Research Center oversees monitoring and research activities for the Grand Canyon population under the auspices of the Glen Canyon Dam Adaptive Management Program. Reaching 20 inches in length, the humpback chub possesses features that distinguish native Colorado River fi shes— large adult body size, small depressed skull, large predorsal hump, and small eyes. These features are assumed to be adaptations to life in the historically turbulent and seasonally sediment-laden Colorado River. Today the species is confi ned to isolated deep canyon stretches of the Colorado River and its tributaries. In Grand Canyon, most humpback chub are found in the Little Colorado River and at its confl uence with the Colorado River. The Grand Canyon population reproduces primarily in the Little Colorado River because mainstem Colorado River temperatures are generally too cold for spawning and juvenile rearing. Humpback chub require a minimum temperature of 16oC (60.8oF) to reproduce. Except during drought conditions, the water-intake structures at Glen Canyon Dam are well below the surface of Lake Powell, where the water is not warmed by the sun. Colorado River temperatures in Grand Canyon generally range from 7oC to 12oC (44.6oF–53.6oF). Humpback chub have been affected not only by dam-induced changes but also through predation by and competition with nonnative fi sh. Fish originating in many parts of the world are currently found in the Colorado River, including introduced species of trout, catfi sh, carp, and bass. Also present in the Colorado River are nonnative fi sh parasites, such as the Asian tapeworm (Bothriocephalus acheilognathi) and anchor worm (Lernaea cyprinacea), which infect some humpback chub and may be a threat.

Status and trends of the Grand Canyon population of Humpback Chub