Greenback Cutthroat trout (Oncorhynchus clarki stomias)

Federal Register | Recovery | Critical Habitat | Conservation Plans | Petitions | Life History

Listing Status:   

Where Listed: WHEREVER FOUND

General Information

Greenback cutthroat trout are coldwater fish belonging to the trout, salmon and whitefish family. They have dark, round spots on the sides and tail and two colorful blood-red stripes on each side of the throat under the jaw, hence the name "cutthroat." During the spring spawning season the entire belly may become crimson red.

  • States/US Territories in which the Greenback Cutthroat trout, Wherever found is known to or is believed to occur:  Colorado , Utah
  • US Counties in which the Greenback Cutthroat trout, Wherever found is known to or is believed to occur:  View All
 
Current Listing Status Summary
Status Date Listed Lead Region Where Listed
1967-03-11 Mountain-Prairie Region (Region 6) Wherever found

» Federal Register Documents

Federal Register Documents
Date Citation Page Title
2005-12-14 00:00:00.0 70 FR 74030 74031 Initiation of a 5-Year Review of Greenback Cutthroat Trout (Oncorhynchus clarki stomias)
2016-05-27 00:00:00.0 81 FR 33698 33700 ETWP; Initiation of 5-Year Status Reviews of 21 Species in the Mountain-Prairie Region
1977-09-26 00:00:00.0 42 FR 48901 48902 Proposed Threatened Status for Greenback Cutthroat Trout; 42 FR 48901 48902 (Salmo clarki stomias)
1978-04-18 00:00:00.0 43 FR 16343 16345 Final Determination of Threatened Status for the Greenback Cutthroat Trout
1967-03-11 00:00:00.0 32 FR 4001 Endangered Species List - 1967
Special Rule Publications
Date Citation Page Title
1977-09-26 00:00:00.0 42 FR 48901 48902 Proposed Threatened Status for Greenback Cutthroat Trout; 42 FR 48901 48902 (Salmo clarki stomias)
1978-04-18 00:00:00.0 43 FR 16343 16345 Final Determination of Threatened Status for the Greenback Cutthroat Trout

» Recovery

Current Recovery Plan(s)
Date Title Plan Action Status Plan Status
1998-03-01 Greenback Cutthroat Trout View Implementation Progress Final Revision 2
Other Recovery Documents
Date Citation Page Title Document Type
2005-12-14 70 FR 74030 74031 Initiation of a 5-Year Review of Greenback Cutthroat Trout (Oncorhynchus clarki stomias)
  • Notice 5-year Review
2016-05-27 81 FR 33698 33700 ETWP; Initiation of 5-Year Status Reviews of 21 Species in the Mountain-Prairie Region
  • Notice 5-year Review, Initiation
Five Year Review
Date Title
2009-05-27 Greenback Cutthroat Trout 5-Year Review

» Critical Habitat

No critical habitat rules have been published for the Greenback Cutthroat trout.

» Conservation Plans

No conservation plans have been created for Greenback Cutthroat trout.

» Petitions

» Life History

Habitat Requirements

This species inhabits cold water streams and cold water lakes with adequate stream spawning habitat present during spring. Field studies however, have indicated that water temperatures averaging 7.8°C or below in July may have an adverse effect on greenback fry (young fish) survival and recruitment. In general, trout require different habitat types for different life stages: juvenile (protective cover and low velocity flow, as in side channels and small tributaries); spawning (riffles with clean gravels); over-winter (deep water with low velocity flow and protective cover); and adult (juxtaposition of slow water areas for resting and fast water areas for feeding, with protective cover from boulders, logs, overhanging vegetation or undercut banks). Both water quality and quantity are important. Greenbacks, like other cutthroat trout, generally require clear, cold, well-oxygenated water.

Food Habits

Greenbacks are opportunistic feeders over a wide range of prey organisms, but a large percentage of the diet can be terrestrial insects. Greenbacks also feed on crustaceans such as fresh-water shrimp, aquatic insects, and small fish.

Movement / Home Range

The original distribution of the subspecies is not precisely known due to its rapid decline in the 1800s. It is assumed that the original distribution included all mountain and foothill habitats of the South Platte and Arkansas river drainage systems, including drainages at lower elevations than it occupies today. The subspecies may have extended as far east as present day Greeley, Colorado, during the mid-1800s. Currently, 145 populations, in 227.7 kilometers (km) of streams and 166.74 hectares (ha) of lakes have been documented within greenback historic range on the eastern side of the Continental Divide.

Reproductive Strategy

Spawning occurs usually from late May to mid-July in higher elevations. Male cutthroat spawn first at age two, and females mature a year later. Females build an egg pit in gravel generally three to eight inches deep and one foot in diameter. A 10-inch female will lay about 800 eggs. Larger fish of about four to seven pounds will lay up to 6,000 eggs.

Other

The main reasons cited for the subspecies’ decline are hybridization, competition with nonnative salmonids, and overharvest. New threats have arisen, or have become more prevalent, and these include: increased human population growth within the range of the subspecies along with potential for new water depletions; new introductions of nonnative species; fragmentation and genetic isolation of small populations; the effects of fire and firefighting with chemical retardants; and the effects of global climate change. Additional threats are those whose impacts are limited to specific populations and do not occur at a rangewide level, and these include: the ongoing negative effects of past mining operations on water quality; the impacts of grazing, logging, and road and trail construction and use on riparian habitat and streambanks, causing increased erosion, sediment deposition, and in turn elevated water temperatures and higher turbidity; and the co-occurrence of nonnative salmonids with greenback populations.

» Other Resources

NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.