Pacific Northwest
Reptiles & Amphibians

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Rocky Mountain Tailed Frog - Ascaphus montanus

Mittleman and Myers, 1949

Alternate Name:

Formerly known as Ascaphus truei - Tailed Frog

Related or Similar Northwest Frogs:

Coastal Tailed Frog


Adult, Bonner County, Idaho	Adult, Bonner County, Idaho	Adult, Bonner County, Idaho

Adult, Bonner County, Idaho	Adult, Bonner County, Idaho	Adults, Bonner County, Idaho

Adult male showing his tail-like copulatory organ. This organ, an extension of the cloaca, is used to transfer sperm into the female's cloaca during amplexus. She then holds the fertilized eggs for 9 or 10 months when she swims under a large stone on the bottom of a fast-moving creek and attaches the eggs to the bottom of the stone. This internal fertilization strategy lets tailed frogs breed in fast-moving water without the eggs washing away, which would happen if they were laid and fertilized on the surface of the water.

Adult, Flathead County, Montana	Skeleton of a Coastal Tailed Frog, Ascaphus truei, National Museum of Natural History

Tadpoles

Tadpole at night feeding on top of rocks under the spray from a waterfall, Idaho County, Idaho	Tadpole, Idaho County, Idaho © Mark Gary	Tadpole, Idaho County, Idaho.

Tadpole, Flathead County, Montana	Most tadpoles have mouths at the front of the head, but the mouth of a tailed frog tadpole is underneath the head, which is flattened. The mouth position and head shape, along with specialized folds that create suction, help a tadpole cling to a rock surface while keeping its body close to the rock. This allows it to scrape food off the surface of underwater rocks in fast-moving creeks without letting the swift current wash it downstream.

Habitat

Habitat, Bonner County, Idaho	Habitat, Idaho County, Idaho	Habitat, Bonner County, Idaho

	Habitat, Flathead County, Montana

Northwest Reptiles and Amphibians

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