TORRENT SALAMANDERS: Rhyacotritonidae

PHYSICAL CHARACTERISTICS

Torrent salamanders are small, short-tailed, greenish yellow, large-eyed salamanders. They are 3 to 4.5 inches (8 to 11 centimeters) long with a stocky body, a broad head, eyes that stick out, and a short snout. The legs are small but sturdy. The tail is short, is flat from side to side, and has a small ridge along the top. These salamanders have lungs that do not function.

GEOGRAPHIC RANGE

Torrent salamanders live in the northwestern part of the United States from the Olympic Peninsula in northwestern Washington in the coast ranges to southern Mendocino County in northern California. They live in the Cascade range from the vicinity of Mount Saint Helens, Washington, south to central Oregon.

HABITAT

Torrent salamanders live in densely forested areas near cool water in small, clear, rapidly flowing streams, in rocky areas where water has seeped to the surface, and in cracks in large rocks with thin layers of water cascading over the surface. These habitats almost always are in closed-canopy forests often dominated by coniferous (koh-NIH-fuh-russ) trees, or those that have cones, but some are in river areas dominated by maples and alders, which are deciduous (dih-SIH-juh-wuhs) trees, or those that lose their leaves during cold or dry seasons.

DIET

Scientists believe torrent salamanders eat insects, especially larvae, and other invertebrates (in-VER-teh-brehts), or animals without backbones. Larvae (LAR-vee) are animals in an early stage that change body form in a process called metamorphosis (MEH-tuh-MORE-feh-sis) before becoming adults.

BEHAVIOR AND REPRODUCTION

Scientists do not know how torrent salamanders behave. These salamanders are secretive and are seldom seen. Fertilization (FUR-teh-lih-ZAY-shun), the joining of egg and sperm to start development, takes place inside the female's body. Large, colorless eggs are laid in cold, clear water under rocks or in cracks. The embryos (EHM-bree-ohs), or young animals in the eggs, develop slowly, as do the larvae, which live for three or four years in the water. The larvae go through metamorphosis when they are close to adult size, but scientists do not know how long it takes the transformed salamanders to mature.

TORRENT SALAMANDERS AND PEOPLE

Torrent salamanders help scientists understand the biological characteristics of the Pacific Northwest region.

WHAT'S IN A NAME?

The scientific name for the torrent salamander family, Rhyacotritonidae, comes from the Greek rhyakos, meaning "stream," and Triton, the Greek god of the sea. Despite the common name, a torrent being a violent, rushing stream, these salamanders rarely live in such water, although they may be found nearby.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists one species of torrent salamanders as Vulnerable and two species as Low Risk/Near Threatened. Vulnerable means facing high risk of extinction in the wild. Low Risk/Near Threatened means at risk of becoming threatened with extinction in the future. Clearing of forests is the greatest risk to torrent salamanders, because it damages their habitat.

CASCADE TORRENT SALAMANDER (Rhyacotriton cascadae): SPECIES ACCOUNT

Physical characteristics: Cascade torrent salamanders are 3 to
4.5 inches (7.5 to 11 centimeters) long from tip of snout to tip of tail. The body is stout with a broad head, eyes that stick out, and a relatively short snout. The tail is flat from side to side, has a ridge along the top, and is shorter than the head plus the body. Cascade torrent salamanders usually are rich brown on top and yellowish and sometimes greenish yellow on the belly. The back is marked with darker blotches and speckles. There is a sharp difference between the brown of the back and sides and the yellow of the belly. There are white flecks on the sides above the beginning of the yellow belly. The belly has dark spots, but there are fewer spots than on the back. There are fine gray flecks on the throat and chest. Male Cascade torrent salamanders have swellings on the edges of the belly.

Geographic range: Cascade torrent salamanders live in the United States in the Cascade Mountains. The range extends from near Mount Saint Helens in Washington to central Oregon. These salamanders usually live at a height of less than 2,000 feet (610 meters) above sea level.

Habitat: Cascade torrent salamanders live in streams, usually in heavily forested areas. These salamanders avoid large streams but may be found near them in small, rapidly flowing arms of the streams, where they live under moss-covered rocks, in coarse gravel, in piles of rocks, and in cracks in rocks in areas that are very moist. Water often is flowing through the rocks in thin sheets. Adult Cascade torrent salamanders go onto land but rarely travel more than a few feet (1 meter) from water. The larvae live in the same habitat as adults but stay in the water.

Diet: Scientists believe that Cascade torrent salamanders eat small invertebrates, especially insect larvae and mollusks. Mollusks (MAH-lusks) are animals with a soft, unsegmented body that may or may not have a shell, such as slugs and snails.

Behavior and reproduction: Scientists do not know how Cascade torrent salamanders behave. These salamanders are extremely secretive. They are not seen unless people actively look for them by turning over rocks. Scientists also are not sure how Cascade torrent salamanders reproduce. A related species lays about eight colorless eggs one at a time in cold water flowing through rocks and rock cracks. The eggs probably are slow to hatch in the cold water. Larvae grow slowly, taking three or four years to go through metamorphosis, which they do when they are 1.5 to 1.8 inches (4 to 4.5 centimeters) long.

Cascade torrent salamanders and people: Cascade torrent salamanders have no known importance to people.

Conservation status: The World Conservation Union (IUCN) lists Cascade torrent salamanders as Low Risk/Near Threatened, or at risk of becoming threatened with extinction in the future. The greatest risk to these salamanders is the cutting of forests, which causes the small streams used by these animals to become too hot and to dry up. ∎

FOR MORE INFORMATION

Books:

Bernhard, Emery. Salamanders. New York: Holiday House, 1995.

Duellman, William E., and Linda Trueb. Biology of Amphibians. Baltimore, MD: Johns Hopkins University Press, 1994.

Gunzi, Christiane. Amphibians and Reptiles of North America. San Diego, CA: Thunder Bay, 1995.

Lawlor, Elizabeth P. Discover Nature in Water and Wetlands. Mechanicsburg, PA: Stackpole, 2000.

Llamas Ruiz, Andres. Reptiles and Amphibians: Birth and Growth. New York: Sterling, 1996.

Petranka, J. W. Salamanders of the United States and Canada. Washington, DC: Smithsonian Institution Press, 1998.

Web sites:

Heying, H. "Rhyacotritonidae." Animal Diversity Web.http://animaldiversity.ummz.umich.edu/site/accounts/information/Rhyacotritonidae.html (accessed on April 8, 2005).

"Rhyacotriton (Dunn, 1920) Torrent Salamanders." Livingunderworld.org.http://www.livingunderworld.org/caudata/database/rhyacotritonidae/rhyacotriton (accessed on April 8, 2005).

Wallays, Henk. "Observations on Torrent Salamanders (Rhyacotriton) in Oregon and California." Caudata.org.http://www.caudata.org/cc/articles/Rhyacotriton.shtml (accessed on April 26, 2005).