Gila crassicauda


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Gila crassicauda
Species Authority: (Baird & Girard, 1854)
Common Name/s:
English Thicktail Chub

Assessment Information [top]

Red List Category & Criteria: Extinct ver 3.1
Year Published: 2013
Date Assessed: 2012-02-08
Assessor/s: NatureServe
Reviewer/s: Smith, K. & Darwall, W.R.T.
Facilitator/s: Hammerson, G.A. & Ormes, M.
This species is listed as Extinct because it has not been collected since the 1950s, despite extensive fish surveys.
1996 Extinct
1994 Extinct (Groombridge 1994)
1990 Extinct (IUCN 1990)
1988 Extinct (IUCN Conservation Monitoring Centre 1988)
1986 Extinct (IUCN Conservation Monitoring Centre 1986)

Geographic Range [top]

Range Description: This species formerly was abundant and widespread in lakes and sloughs of the Sacramento-San Joaquin Valley; Clear Lake (Lake County); and Pajaro River, Salinas River, and San Francisco Bay drainages, California (Moyle 2002, Page and Burr 2011). The last specimen was collected from Cache Slough, near Rio Vista, in late 1950s (Moyle 1976, Miller et al. 1989).
United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: None remaining.

This species was still numerous through the 1880s. Evidence indicates that it was the third most abundant food source for local Indians before European settlement (Day 1981). Formerly it was sold in fish markets.

Habitat and Ecology [top]

Habitat and Ecology: Habitat includes marshes and backwaters along rivers and lake margins (Page and Burr 2011). Thicktail chubs were originally abundant in lowland lakes and sloughs, slow-moving stretches of river, and, during years of heavy run-off, the surface waters of San Francisco Bay (Moyle 1976).
Systems: Freshwater

Threats [top]

Major Threat(s): Extinction probably resulted from change in habitat: removal of tule beds; drainage of large lakes; reduction in stream flows; alteration of stream channels; introduction of exotic species (Moyle 1976). Dam building, introduction of non-native competitors, interbreeding and hybridization, and water diversion for irrigation all contributed to extinction (Day 1981).

Conservation Actions [top]

Conservation Actions: This species is extinct.
Citation: NatureServe 2013. Gila crassicauda. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 16 April 2014.
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