Description
A small species of Ambystoma, dark gray to black with a yellow, tan or olive green dorsal stripe often broken up into blotches (Stebbins 1951). The sides have some white speckling. The ventral side is gray or black (Petranka 1998).

Ambystoma macrodactylum columbianum A. m. croceum, A. m. krausei, A. m. macrodactylum, A. m. sigillatum are subspecies.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Canada, United States

U.S. state distribution from AmphibiaWeb's database: California, Idaho, Montana, Oregon, Washington

Canadian province distribution from AmphibiaWeb's database: Alberta, British Columbia

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (185 records).

Their range extends from south-eastern Alaska south to northern California, and from the Pacific coast east to north-central Idaho and western Montana (Petranka 1998). Found in a variety of habitats from coniferous forests to sagebrush plains to alpine meadows. Found on the ground under bark, rocks, and rotting wood piles. Also found in the quiet water of streams, ponds and lakes (Stebbins 1951).

Life History, Abundance, Activity, and Special Behaviors
Life history varies greatly with elevation and climate. Each season individuals migrate to breeding ponds with males arriving earlier and staying longer than females (Beneski et al 1986). At low elevations this migration may be in October or November, but at higher elevations it does not occur until snowmelt in late spring (Petranka 1998). Males deposit spermatophores (packets of sperm) which females pick up after courtship. Single eggs or loose egg clumps are attached to vegetation or detritus. Larvae hatch 2-5 weeks later and metamorphose in about 3 months (Petranka 1998).

Trends and Threats
Eggs exposed to ambient levels of UV-B radiation have been shown to have increased mortality and incidence of deformities than those shielded from UV-B (Blaustein et al 1997). A trematode has been found that disrupts both limb development and regeneration and has been proposed as an explanation of why individuals with supernumerary limbs are found (Sessions and Ruth 1990). Environmental contaminants as well as the introduction of non-native fish predators may also threaten this species. The destruction of wetland habitats may prove to be the greatest threat. The subspecies, A. m. croceum, persists in only a few scattered populations and is threatened with extinction (Petranka 1998).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Predators (natural or introduced)

Comments
The species epithet, "macrodactyla," is from the Greek words, "macros," meaning “long,” and "daktylos," meaing “toe,” which is a reference to the species' long toes (Tighe 2023).

See other subspecies accounts at www.californiaherps.com: A. m. croceum and A. m. sigillatum.

References

Beneski, J. T. Jr., Zalisko, E. J., and Larsen, J. H. (1986). ''Demography and migratory patterns of the Eastern Long-toed Salamander Ambystoma macrodactylum columbianum.'' Copeia, 1986, 398-408.

Blaustein, A. R., Kiesecker, J. M., Chivers, D. P., and Anthony, R. G. (1997). "Ambient UV-B radiation causes deformities in amphibian embryos." Proceedings of the National Academy of Sciences of the United States of America, 94(25), 13735-13737.

Petranka, J. W. (1998). Salamanders of the United States and Canada. Smithsonian Institution Press, Washington D.C. and London.

Sessions, S. K., and Ruth, S. B. (1990). ''Explanation for naturally occurring supernumerary limbs in amphibians.'' Journal of Experimental Zoology, 254, 38-47.

Stebbins, R.C. (1951). Amphibians of Western North America. University of California Press, Berkeley.

Tighe, K.A. (2023). Catalog of type specimens of recent Caudata and Gymnophiona in the National Museum of Natural History, Smithsonian Institution. Smithsonian Contributions to Zoology 654.

Species Account Citation: AmphibiaWeb 2023 Ambystoma macrodactylum: Long-toed Salamander <https://amphibiaweb.org/species/3840> University of California, Berkeley, CA, USA. Accessed Dec 27, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Dec 2024.

AmphibiaWeb's policy on data use.