The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Batrachoseps attenuatus
Batrachoseps attenuatus
(California Slender Salamander)
Native Transplant

Copyright Info
Batrachoseps attenuatus (Eschscholtz, 1833)

Common name: California Slender Salamander

Taxonomy: available through www.itis.govITIS logo

Identification: Very slender, with tail approximately twice as long as body (snout-vent length, SVL); short limbs, with hind feet each having four digits; red, brown, or yellow dorsal stripe that varies with geographic locale (Stebbins and McGinn 2012).

Size: 32-47 mm SVL, ~150 mm

Native Range: Extreme southwestern Oregon south to the South Coast Range, CA, as well as scattered populations in Sierran foothills and Great Valley, CA (Stebbins and McGinnis 2012).

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences: One pregnant female was captured in Kirkland, WA (Freni et al. 2022).

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Batrachoseps attenuatus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
WA202020201Lake Washington

Table last updated 2/21/2024

† Populations may not be currently present.

Ecology: Relatively common in urban and suburban areas such as gardens and parks, including disturbed areas and those with other invasive species such as ice plant (Mesembryanthemum sp.), but natural habitat includes oak savannah, chaparral, woodland, and forests where (Stebbins and McGinnis, 2012). California Slender Salamanders are typically found under leaf litter, logs, rocks, and other debris, and may use earthworm burrows; eggs are laid underground or under debris, and communal "nesting" by several individuals is thought to occur (Stebbins and McGinnis 2012). Diet consists of small invertebrates, such as small slugs and snails, spiders, mites, millipedes, isopods, insects, and newly-hatched earthworms within earthworm burrows (Stebbins and McGinnis 2012).

Means of Introduction: Most likely interstate transport of plants or timber, but possibly a released or escaped pet (Freni et al. 2022).

Status: Unknown, but individual captured in Kirkland, WA was a pregnant female (Freni et al. 2022).

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

References: (click for full references)

Freni, O., J. Freni, C.D. Anderson, L. Hallock, M.R. Lambert, N. Van Gilder, D.B. Wake, E.L. Jockusch. 2022. First record of a Slender Salamander (Genus Batrachoseps) introduced to Washington State and molecular source identification from San Francisco, California. Northwestern Naturalist 103(1):81-87.

Stebbins, R.C. and McGinnis, S.M. 2012. Amphibians and reptiles of California. Revised edition. California Natural History Guides, Berkeley, CA.


Author: Freedman, J.A.

Revision Date: 3/14/2022

Citation Information:
Freedman, J.A., 2024, Batrachoseps attenuatus (Eschscholtz, 1833): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=3799, Revision Date: 3/14/2022, Access Date: 2/21/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is 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 information.


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. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [2/21/2024].

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