The ensatina (''Ensatina eschscholtzii'') is a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

of plethodontid (lungless)

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s found in coniferous forests, oak woodland and

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

Monterey Ensatina
San Diego Field Station,

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

Viewed: April 24, 2005, Last updated: March 05, 2003 from

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, through Washington,

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, across

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

(where all seven subspecies variations are located), all the way down to

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in Mexico. The genus ''Ensatina'' originated approximately 21.5 million years ago. It is usually considered as

monospecific In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

, being represented by a single species, ''Ensatina eschscholtzii'', with several subspecies forming a ring species.

Description

The subspecies ''Ensatina e. eschscholtzii'', the Monterey ensatina, can be found in Santa Cruz and Monterey Counties and into the California coastal mountains. With a head-to-tail length of just between , ''E. e. eschecholtzi'' can be identified primarily by its tail, which is narrower at the base; it is the only subspecies that has such a tail structure, as well as five toes on the hind limbs. Males often have longer tails than the females, and many of these salamanders have lighter-colored limbs, compared to the rest of the body. The adult females lay eggs underground, often in sets of threes, which hatch directly into fully-formed salamanders, skipping the usual aquatic juvenile phase. The subspecies ''Ensatina eschscholtzii klauberi'', or the large-blotched ensatina, can be found along the mountain ranges of

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

, and south into a small region of the Sierra Juarez in northern

. ''E. e. klauberi'' is similar in size to ''E. e. eschscholtzii''; it is mid-sized, with adults growIng a total length of . Females tend to have shorter, wider bodies compared to the males. However, this subspecies differs from ''E. e. eschscholtzii'' in its coloration—nearly black, with blotches of orange, tail, and dark eyes.

As a ring species

''Ensatina eschscholtzii'' has been described as a

ring species In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end populations" in the series, which are too distantly relate ...

in the mountains surrounding the Californian Central Valley. The complex population forms a

horseshoe A horseshoe is a product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, altho ...

shape around the mountains, and although interbreeding can happen between each of the 19 populations around said horseshoe, the ''Ensatina eschscholtzii'' subspecies on the western end of the horseshoe cannot interbreed with the ''Ensatina klauberi'' on the eastern end. As such, it is thought to be an example of incipient speciation, providing an illustration of "nearly all stages in a speciation process" (Dobzhansky, 1958). Richard Highton,

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

, argued that ''Ensatina'' is a genus of multiple species and not a continuum of one (meaning, by traditional definitions, it is not a ring species).

Distribution and habitat

They are generally thought to be found in high elevations, from 520 to 2400m, in conifer forests and oak woodlands. However, populations were discovered along the coast in Volcán Riveroll, a volcanic area located in Baja California. It is thought that they are able to survive in this anomalous region due to the high moisture that comes in from the coast. It is unclear how these populations were able to end up in this coastal region, but it is hypothesized that “the subspecies was once more broadly distributed and became isolated as a result of climate change during the late Pleistocene and Holocene.” If this is true, then it is estimated that ''Ensatina klauberi'' has been living in this region for thousands of years.

Relationships with humans

''Ensatina'' can usually be found under logs or brush, by or in streams and lakes, and in other moist places. They are easily distressed by improper handling, because they rely on

cutaneous respiration Cutaneous respiration, or cutaneous gas exchange (sometimes called skin breathing), is a form of respiration in which gas exchange occurs across the skin or outer integument of an organism rather than gills or lungs. Cutaneous respiration may be ...

, their thin skin is very sensitive to heating, drying and exposure to chemicals from warm hands. They may exude a sticky milky secretion from the tail.

Subspecies

*Yellow-blotched ensatina — ''E. e. croceater'' (Cope, 1868) *Monterey ensatina — ''E. e. eschscholtzii'' Gray, 1850 *Large-blotched ensatina — ''E. e. klauberi'' Dunn, 1929 *Oregon ensatina — ''E. e. oregonensis'' (Girard, 1856) *Painted ensatina — ''E. e. picta'' Wood, 1940 *Sierra Nevada ensatina — ''E. e. platensis'' (Jiménez de la Espada, 1875) *Yellow-eyed ensatina — ''E. e. xanthoptica'' Stebbins, 1949

References

External links

* *
''Ensatina'' Salamander
page at Santa Rosa Junior College Department of Life Sciences
''Ensatina'' Salamander
page at AmphibiaWeb {{Taxonbar, from=Q1885015 Plethodontidae Monotypic amphibian genera Amphibians of North America Taxa named by John Edward Gray