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The ensatina (''Ensatina eschscholtzii'') is a species complex of
San Diego Field Station, United States Geological Survey Viewed: April 24, 2005, Last updated: March 05, 2003 from British Columbia, through Washington, Oregon, across California (where all seven subspecies variations are located), all the way down to Baja California in Mexico. The genus Ensatina originated approximately 21.5 million years ago. It is usually considered as monospecific, being represented by a single species, ''Ensatina eschscholtzii'', with several subspecies forming a ring species.
The ensatina subspecies ''E. e. eschscholtzii'', or Monterey ensatina, can be found in Santa Cruz, Monterey, and the California coastal mountains. They reach a total length of three to five inches, and can be identified primarily by the structure of the tail, and how it is narrower at the base. This salamander is the only type that has this tail structure and five toes on the back feet.
Males often have longer tails than the females, and many of the salamanders have lighter colored limbs in comparison to the rest of the body. The salamanders lay their eggs underground, often in threes, which then hatch directly into salamanders, skipping the usual aquatic phase.
Incipient species formation in salamanders of the ''Ensatina'' complex
Proceedings of the National Academy of Sciences USA 94:7761-7767 The complex forms a
*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
''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
plethodontid
Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In ...
(lungless) salamanders found in coniferous forests, oak woodland and chaparral
Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...
Monterey EnsatinaSan Diego Field Station, United States Geological Survey Viewed: April 24, 2005, Last updated: March 05, 2003 from British Columbia, through Washington, Oregon, across California (where all seven subspecies variations are located), all the way down to Baja California in Mexico. The genus Ensatina originated approximately 21.5 million years ago. It is usually considered as monospecific, being represented by a single species, ''Ensatina eschscholtzii'', with several subspecies forming a ring species.
Habitat and description
The ensatina subspecies ''E. e. eschscholtzii'', or Monterey ensatina, can be found in Santa Cruz, Monterey, and the California coastal mountains. They reach a total length of three to five inches, and can be identified primarily by the structure of the tail, and how it is narrower at the base. This salamander is the only type that has this tail structure and five toes on the back feet.
Males often have longer tails than the females, and many of the salamanders have lighter colored limbs in comparison to the rest of the body. The salamanders lay their eggs underground, often in threes, which then hatch directly into salamanders, skipping the usual aquatic phase.
As a ring species
''Ensatina eschscholtzii'' has been described as a ring species in the mountains surrounding the Californian Central Valley.Wake, D. (1997Incipient species formation in salamanders of the ''Ensatina'' complex
Proceedings of the National Academy of Sciences USA 94:7761-7767 The complex forms a
horseshoe
A horseshoe is a fabricated 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 toen ...
shape around the mountains, and though interbreeding can happen between each of the 19 populations around the 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, and provides an illustration of "nearly all stages in a speciation process" (Dobzhansky, 1958). Richard Highton argued that ''Ensatina'' is a case of multiple species and not a continuum of one species (meaning, by traditional definitions, it is not a ring species).
Human contact
The 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, 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 tailSubspecies
*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