AMPHIBIAWEB
Taricha rivularis
Red-bellied Newt, Redbelly Newt
Subgenus: Twittya
family: Salamandridae
subfamily: Pleurodelinae

© 2006 Henk Wallays (1 of 59)
Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
NatureServe Status Use NatureServe Explorer to see status.
CITES No CITES Listing
Other International Status None
National Status None
Regional Status Species of Special Concern

 

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Description
A stocky, medium to large salamander. Terrestrial adults have a brownish black dorsum and bright red venter. The skin is grainy in appearance. Aquatic males (breeding season only) have a brownish dorsum with bright red venter, and a broad, dark stripe across vent. The skin is smooth or slimy (Stebbins 1972; Petranka 1998). Snout to vent length of adults 5.9 to 8.1 cm (14-19.5 cm total length. Larvae are pond-type with incompletely developed or non-existent balancers and even, dark pigmentation on the sides and dorsum. A moderately high tail fin extends forward but does not reach the shoulders (Stebbins 1985; Petranka 1998).

Taricha rivularis may be distinguished from close relatives (T. granulosa and T. torosa) by relatively prominent eyes, brown iris, and bright red ventral coloration (Stebbins 1951; Petranka 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: California

 

View distribution map using BerkeleyMapper.
The range of red-bellied newts covers northwest California, including Sonoma, Mendocino, and Humboldt Counties. The habitat is characterized by coastal redwood forests and cold, rocky, forest streams with moderate to fast current (Petranka 1998; Stebbins 1972).

In 2014, several individuals were discovered in Santa Clara County, significantly south (ca. 130 km) from its previously known range (Reilly et al 2014). These adults were seen with egg masses so recruitment is likely. Reilly et al (2014) tried to determine the origin of this disjunct population by comparing a few molecular markers with populations from the north of San Francisco Bay. However due to the extremely low genetic diversity across its range it was inconclusive whether the population in Santa Clara County represents a previously unknown but natural range extension or an introduced population.

Life History, Abundance, Activity, and Special Behaviors
Adults appear above ground after the first few rains during the autumn months and begin to orient towards breeding sites in late January, with peak migration in early March. Movements are concentrated in the five hours following sunset on warmer, humid nights with moderate or no rain. Breeding occurs in fast-moving streams, and does not take place in standing water like related species of Taricha. Animals show philopatry and return to the same (or nearby) sites to breed each year. Courtship includes a period of amplexus where the male grasps the female and rubs her head with his. Eventually, the male deposits a spermatophore on the substrate and the female picks this up in her cloaca. Females deposit eggs in small, flattened masses, usually one layer thick. Masses contain 5-15 eggs, average 9. Egg deposition sites are in fast-flowing water on the undersides of stones or attached to rootlets. Eggs hatch after 20-30 days and larvae metamorphose after four months (by August). The juvenile stage lasts 5 years, during which time the animal is rarely seen above ground. Individual red-bellied newts may live as long as 15 years. See Petranka (1998) for references.

Diet is likely composed of terrestrial and aquatic invertebrates although this has been poorly studied (Petranka 1998). When attacked, T. rivularis assumes the characteristic "unken reflex" of all species of Taricha: the tail and head are raised to expose the bright red belly as a warning to predators (Brodie 1977). All Taricha produce the neurotoxin known as tetrodotoxin, which is toxic to their predators and humans (Brodie et al. 1974; Petranka 1998).

Trends and Threats
Taricha rivularis can be considered common. However, long-term population studies are lacking for this species (Petranka 1998).

Based on low genetic diversity, limited geographic range and potential habitat, and high potential for habitat disturbance, Reilly et al (2014) recommends conservation protection for this species.

Possible reasons for amphibian decline

Loss of genetic diversity from small population phenomena

Comments

See another account at californiaherps.com.

References

Brodie, E. D., Jr. (1977). "Salamander antipredator postures." Copeia, 1977, 523-535.

Brodie, E. D., Jr., Hensel, J. L., and Johnson, J. A. (1974). ''Toxicity of the urodele amphibians Taricha, Notophthalmus, Cynops, and Paramesotriton (Family Salamandridae).'' Copeia, 1974(2), 506-511.

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

Reilly, S.B., Portik, D.M., Koo, M.S., and Wake, D.B. (2014). ''Discovery of a New, Disjunct Population of a Narrowly Distributed Salamander (Taricha rivularis) in California Presents Conservation Challenges.'' Journal of Herpetology, 48(3), 371-379 .

Stebbins, R. C. (1972). Amphibians and Reptiles of California. University of California Press, Berkeley, Los Angeles, London.

Stebbins, R. C. (1985). A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin, Boston.

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

Twitty, V. C. (1964). ''Taricha rivularis (Twitty). Red-bellied Newt.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 9.1-9.2.



Written by Rachel L. Mueller and Meredith J. Mahoney, updated Michelle Koo (rachel AT socrates.berkeley.edu, molge AT yahoo.com), Museum of Vertebrate Zoology, University of California, Berkeley
First submitted 1999-02-22
Edited by M. J. Mahoney, Kevin Gin, Michelle Koo (2018-02-23)

Species Account Citation: AmphibiaWeb 2018 Taricha rivularis: Red-bellied Newt <http://amphibiaweb.org/species/4289> University of California, Berkeley, CA, USA. Accessed Nov 12, 2018.



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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Nov 2018.

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