Gambusia geiseri


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Gambusia geiseri
Species Authority: Hubbs & Hubbs, 1957
Common Name(s):
English Largespring Gambusia

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2013
Date Assessed: 2012-02-03
Assessor(s): NatureServe
Reviewer(s): Smith, K. & Darwall, W.R.T.
Facilitator/Compiler(s): Hammerson, G.A. & Ormes, M.
Small area of occupancy, but listed as Least Concern in view of the several subpopulations and locations, increased distribution and abundance (compared to historical situation), apparently stable trend, and lack of major threats.

Geographic Range [top]

Range Description: Historically this species occupied Comal (Guadalupe River system) and San Marcos springs, central Texas; it has been widely introduced in springs in the Colorado and Rio Grande (including Pecos River) drainages in western Texas (Minckley et al. 1991, Page and Burr 2011).
United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Nine localities in western and central Texas were mapped by Lee et al. (1980). Formerly in two springs and spring runs; now in four more (C. Hubbs pers. comm. 1995).

Abundance is ten times historical level (C. Hubbs pers. comm. 1995).

Trend over the past 10 years or three generations is uncertain but likely to be relatively stable.
Population Trend: Stable

Habitat and Ecology [top]

Habitat and Ecology: Habitat includes cool, clear, high-volume discharge springs near their emergence from underground limestone aquifers; this species is often in swift water (Lee et al. 1980, Page and Burr 2011).
Systems: Freshwater

Threats [top]

Major Threat(s): This species is probably secure, based on numbers and "wide" distribution (Minckley et al. 1991). No significant threats are known (C. Hubbs pers. comm. 1995).

Conservation Actions [top]

Conservation Actions: Currently, this species is of relatively low conservation concern and does not require significant additional protection or major management, monitoring, or research action.

Citation: NatureServe 2013. Gambusia geiseri. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 28 August 2015.
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