Ambystoma macrodactylum
(Long-toed Salamander)

Key Characteristics:

Adult Characteristics

Larval Characteristics

Egg Characterisitcs

Extra long 3th
toes on hind feet

Long feathery
external gills

Pigmented

Solid or broken dorsal stripe

9-12 gill rakers
on third arch

Singly or clusters up to 100

Lack parotoid glands

Balancers present on early larvae

Attached or loose

Costal grooves

.

Cluster usually linear

Tubercules
present on feet

. .

General Description:
These small salamanders (up to 85mm) have a dark ground color (dark brown to black) with a dorsal stripe running from nose to tail. This dorsal stripe may have uneven edges or may even be broken into blotches. The color of the dorsal stripe varies from shades of yellow to green.  Long-toed Salamanders have bluish flecks on their sides, and their ventral coloration  is generally grayish.

The characteristic that is the namesake for this species is the extra long 3th toe on the hind feet. The specific epithet also describes this trait, it translates as "large digit (toe)".

The costal grooves of Long-toed Salamanders are readily apparent and the general body form resembles that of the Tiger Salamander (albeit more petite). Long-toed Salamanders can be distinguished from the Coeur d'Alene Salamander (Family: Plethodontidae) by the absence of both nasolabial grooves and the absence of a pale patch under the chin.

The larvae of Long-toed Salamanders can be distinguished by their uniform dorsal coloration and their long feathery external gills (with 9-12 gill rakers ).  During their early development, Long-toed Salamanders have dermal projections on each side of their head.   These projections are called balancers and may aid the larvae in keeping their balance and preventing them from sinking to the muddy bottom (Pough, 1998).

Long-toed Salamanders have pigmented eggs that are approximately 2.5mm in diameter. These eggs can be laid singularly or in clutches up to 100. The eggs can either be attached to submerged vegetation and debris or they can be loose on the substrate.

Idaho Distribution:
In Idaho, Long-toed Salamanders are more widespread than any other salamander species. They are found throughout northern and down into central Idaho.

Habitat:
From shrub steppe to alpine meadows (up to 3050 m), in variety of habitats including dry woodlands, humid forests, and rocky shores of mountain lakes.  

Long-toed Salamanders are generally found in moist areas in a variety of habitats ranging from desert brush, open forests, developed areas and high mountain meadows. During the breeding season, they can be found in or near ponds, vernal pools or small lakes.

Diet:
Larvae feed on zooplankton, immature insects, snails, and (occasionally) other salamander larvae. Adults eat terrestrial and aquatic invertebrates, including insects, insect larvae, spiders, slugs, earthworms, and amphipods.

Ecology:
Hibernates/aestivates. Adults are subterranean, except during breeding season. Predators of larvae probably include aquatic insects and garter snakes; garter snakes and bullfrogs eat adults.

Reproduction:
In Idaho, elevation affects breeding season and clutch size. Populations below 2100 m breed in spring; those above 2100 m breed in midsummer. Clutch size is larger at lower elevations. Larvae metamorphose in first summer or, at high elevations, overwinter.

Conservation:

Status:

Unprotected nongame species

Global Rank:

G5

State Rank:

S5

Important State References:
Howard, J.H. and R.L. Wallace. 1985. Life history characteristics of populations of the long-toed salamander (Ambystoma macrodactylum) from different altitudes. Amer. Midl. Nat. 113: 361-373.


Original images provided by Charles R. Peterson, 1997
Species description, key characteristics and original html by John Cossel Jr. 1997.
Species ecological information from Groves et al.© 1997.
Updated design, image optimization and final revision by Ean Harker ©1999, 2000.
Adaptation for DAI by Stephen Burton and Mike Legler 1999.