Long-toed Salamander

Contents:
 
Links:
Taxon, Status, and Ranks Habitat Photos
General Description State Status Comments
Identification Tips Inventory & Research Needs Key Features
Phenology Threats & Mgmt Concerns
Range References Distribution Map

Taxon, Status, and Rank

Species Ambystoma macrodactylum     Baird, 1849
Family Ambystomatidae
(Mole Salamanders)
Status None
State Rank S5
Global Rank G5

General Description

This is a medium-sized dark gray or black salamander with an irregular yellow, olive or green dorsal stripe, distinct costal grooves, a broad head and rounded snout. Adults range in size from 5.0 to 8.1 cm (2 1/8 – 3 1/4 in.) snout-vent length. The dorsal stripe is often irregular and broken into spots. The sides of the body have blue or white speckling. The underside is black or gray. The tail is laterally compressed. The common name refers to the unusually long fourth hind toe (next to the outer-most toe). During the breeding season males have a swollen vent.

Hatchlings are 6-12 mm total length and have balancers (rod-like structures on each side of the head). Larvae are typical pond type with large gills and a high tail fin. Gill filaments are “ragged” and uneven in length. The top gill filament is usually longer than the remaining gill filaments on the stalk. Fewer than 13 gill rakers exist on the anterior face of the third gill arch. Larvae rarely exceed 85 mm total length. The dorsal stripe develops at metamorphosis.

Egg laying behavior, with eggs being laid both singly and in masses, is highly variable. Some variability is geographic and may reflect incomplete understanding of Long-toed Salamander systematics. Eggs may be attached to vegetation, the underside of logs or laid unattached on bare sediments. Both single eggs and egg masses may be present at the same breeding site. Single eggs may be spread throughout the habitat or clustered in small clumps on vegetation. The egg masses typically contain 10-20 eggs, but smaller or larger clusters are common. Individual eggs (ovum and gelatinous envelope together), whether laid singly or in a mass, measure 10 mm or greater in diameter. The ova are approximately 2.0 - 2.5 mm in diameter, with dark animal poles and gray or white vegetal poles. Except in newly laid eggs, the gelatinous envelope is loose and watery and does not hold its shape out of water. Development time to hatching is 2-5 weeks depending on water temperature. See Photos Page.

Identification Tips

The Northwestern Salamander has parotoid glands behind the eyes and a glandular ridge along the dorsal margin of the tail and lacks a dorsal stripe. The Tiger Salamander has spots and blotches that extend onto the sides of the body and may extend onto the belly. The fourth hind toe is not exceptionally long and the Tiger Salamander lacks white or blue speckling on the sides of the body. Washington Woodland Salamanders (Plethodontids) differ in having a uniformly narrow body shape, a more pointed snout that narrows in front of the eyes, nasolabial grooves, a fourth hind toe similar in length to the other toes, and a tail that is round in cross section not laterally compressed.

Larvae - Newt larvae have eyes on the margin of the head, a snout that narrows in front of the eyes, a faint horizontal stripe from the snout through the eye and one or two rows of white or yellow spots down the back and sides.

At hatching, Long-toed Salamanders have balancers and Tiger Salamanders do not. Otherwise, the small larvae (less than 25 mm TL) of the three species of Mole Salamander (Genus Ambystoma) native to Washington are similar in appearance. With experience, one can recognize differences in the gills, the way the larvae hold their gills, head size, head shape and coloration. Differences are subtle and may not be obvious to the novice. Corkran and Thoms (1996) illustrate these differences in their field guide.

Larger larvae are easier to distinguish. Tiger Salamander and Northwestern Salamander larvae grow larger (>77 mm total length, 35 mm snout-vent length) and develop huge gills and robust legs and toes. Northwestern Salamander larvae have glandular patches on the head and tail. Tiger Salamander larvae have more than 13 gill rakers on the anterior face of the third gill arch.

Eggs – Tiger Salamanders and Rough-skinned Newts lay small single eggs (ovum and gelatinous envelope together) that are less than 10 mm in diameter when fully expanded. Pacific Treefrogs and Great Basin Spadefoots have egg masses that are similar, but both species have individual eggs (ovum and gelatinous envelop together) that are 5 mm or less in diameter when fully expanded. See Key Features Page.

Phenology

Long-toed Salamanders in lowland areas of western Washington start breeding as early as January. In the Columbia Basin, egg laying takes place primarily in March and April. Breeding at higher elevations starts later and timing varies depending on elevation and site conditions. Egg development time to hatching is two to three weeks depending on water temperature. The length of the larval period is variable depending on site conditions; food resources and temperature appear to strongly influence differences. Metamorphosis takes place in the summer or fall of the first year. At high elevations, larvae may overwinter and transform the following year.

Range

Long-toed Salamanders are the most widespread, possibly the most common salamander species in Washington and occur in all ecoregions. Occurrences are sparse in coastal areas of the Pacific Northwest Coast Ecoregion and in the driest portions of the central arid shrub-steppe zone of the Columbia Basin Ecoregion. See Distribution Map.

For information on the complete range of this species, see NatureServe Explorer.

Habitat and Habits

Long-toed Salamanders use a variety of habitats and persist in many urban and disturbed areas. Terrestrial habitats include sagebrush communities, coniferous forest, ponderosa pine – Oregon oak and alpine meadows. Eggs and larvae have been observed in wetlands, ponds, lakes, slow flowing springs, road ditches, spring boxes, large puddles and other types of seasonal pools. Long-toed Salamander are typically sparse or absent from water bodies with fish, although this varies with habitat complexity. Transformed salamanders spend most of their lives underground except when migrating to and from breeding sites. They are thought to be poor burrowers and may generally depend on interstitial spaces between rocks or where roots, rotting wood, or the tunnels of other animals allow easy underground access. While surface active in the spring, they seek refuge under decaying logs, loose bark, rocks and other structures that retain moisture. Overwintering habitat in Washington has not been described but is most likely subterranean.

State Status Comments

Long-toed Salamanders are the most widespread and, frequently, the most abundant salamander species encountered in Washington and do not appear to require special conservation actions at this time. However, historically introduction of salmonid fishes, especially brook trout, to a broad range of high elevation lakes, may have resulted in lower abundance and occupancy of Long-toed Salamanders in those systems.

Inventory and Research Needs

Specific inventory needs do not appear to be pressing at this time. However, as Long-toed Salamanders seem to have a relatively low tolerance for co-occurrence with predatory fishes, especially exotic species, a better understanding of this phenomenon in context of their current distribution is needed. Several warm water fish species, now widespread in lowland habitats in Washington, appear to have negative interactions with other amphibians, but their impacts on Long-toed Salamanders are largely unstudied. One potential effect of these introductions is that Long-toed Salamanders may use more temporary water bodies for breeding than occurred historically because the exotic species occupy the permanent water bodies. Given recent reinterpretation of the Clean Water Act to exclude small isolated wetlands from protection, if such wetlands are the ephemeral category with a high level of use by Long-toed Salamanders, the remaining strongholds of the Long-toed Salamander may now be increasingly precarious. This deserves study.

Observations that occur in areas that are not indicated on the distribution map can be submitted to the Washington Department of Fish and Wildife herp database by contacting Lori Salzer by E-mail salzeljs@dfw.wa.gov.

Threats and Management Concerns

Larval abundance is reduced or eliminated in alpine lakes with introduced trout. This should be considered before non-native fish are introduced to Long-toed Salamander breeding habitats. Similar patterns may be occurring in lowland systems, but except for localized study, are unexamined to date.

References

Adams (1999), Adams et al. (2003), Corkran and Thoms (1996), Duelman and Trueb (1986), Hallock (1998), Leonard et al. (1993), Nussbaum et al. (1983), Petranka (1998), Stebbins (2003), Tyler et al. (1998).

 

Personal communications: M. Hayes




Hallock, L.A. and McAllister, K.R. 2005. Long-toed Salamander. Washington Herp Atlas. http://www1.dnr.wa.gov/nhp/refdesk/herp/

Last updated: February 2005


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