Gambusia affinis
Gambusia affinis
(Western Mosquitofish)
Fishes
Native Transplant
Collection Info
Point Map
Species Profile
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12 results for Gambusia affinis (Western Mosquitofish)
Download Data

Specimen IDStateCountyLocalityYear HUC Number What's this? Drainage nameStatus
1458928 CA San Joaquin (HUC6) non-specific1970 18040000 San Joaquinestablished
1458929 CA San Joaquin (HUC6) non-specific1986 18040000 San Joaquinestablished
1885916 CAAmadorSouth Fork Cosumnes River2000 18040013 Upper Cosumnes 
748002 CAContra CostaKellogg Creek, near intersection of Camino Diablo Rd.and Vasco Rd.1973 18040003 San Joaquin Deltaestablished
1885913 CAEl DoradoNorth Fork Cosumnes River2000 18040013 Upper Cosumnes 
29618 CAFresnoSan Joaquin River at Friant1940 18040001 Middle San Joaquin-Lower Chowchillaestablished
1885904 CASacramentoMainstem Cosumnes river at Hwy 162000 18040013 Upper Cosumnes 
747854 CASan JoaquinSan Joaquin County: Corral Hollow Creek, 4 km W of I-51990 18040003 San Joaquin Deltaestablished
282399 CASan Joaquinwater diversions and pumping facilities at the Tracy [CA] Fish Collection Facility (USBR)1999 18040003 San Joaquin Deltaestablished
748006 CAStanislausDel Puerto Creek at Hwy 33 bridge1973 18040002 Lower San Joaquin Riverestablished
748003 CAStanislausDel Puerto Creek, 13.7 miles W. of I5 on Del Puerto Canyon Rd.1973 18040002 Lower San Joaquin Riverestablished
747895 CATuolumneWoods Creek (near Jamestown)1978 18040009 Upper Tuolumneestablished

Data Disclaimer: Number of records does not imply species abundance. This summary represent collection records only and may not reflect the actual distribution of established populations. These data are preliminary or provisional and are subject to revision. They are being provided to meet the need for timely best science. The data have not received final approval by the U.S. Geological Survey (USGS) and are provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the data.

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The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2026]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [3/13/2026].

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