Description
A large-bodied salamander. Terrestrial adults have a light brown to dark brown dorsum with a yellowish to orange belly. The skin is dry with small bumps or warts and costal grooves are not visible. The eyes are large and the lower eyelids are yellow. Adult males in the breeding season develop smooth or slimy skin, a lighter body color, enlarged tail fins, and swollen cloacal glands (Storer, 1925; Stebbins, 1985). Adults are 6.9 - 8.7 cm snout to vent lenght (12.5 - 20 cm total length) (Stebbins 1985; Petranka 1998).

The eyelids and snout have conspicuous light coloring. Taricha torosa, the Coast Range newt, is yellowish to dark brown dorsally and pale yellow to orange ventrally. The eyelids and snout are not as conspicuously colored as in T. sierrae. (Riemer 1958; Stebbins 1985; Petranka 1998).

Taricha torosa may be distinguished from close relatives, which co-occur (T. granulosa and T. rivularis), by the Y-shaped pattern of the vomerine teeth, the light-colored lower eyelids, relatively large eyes, and lack of a tomato red belly. The defensive posture differs between T. torosa and T. granulosa (see below) (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 in BerkeleyMapper.
	View Bd and Bsal data (1693 records).

The Coast Range newt ranges from Mendocino Co. south through the Coast Range to the western slope of the Peninsular ranges in San Diego Co. The southern-most locality (San Diego Co.) is isolated geographically from the remaining coastal populations. A gap in the distribution also exists in Santa Barbara Co. (Jennings and Hayes 1994; Stebbins 1985). It is endemic to California state.

Terrestrial adults are found in mesic forests in relatively mountainous areas of northern California. Further south, they can be found in drier habitats such as oak woodlands or hilly grasslands (Petranka 1998). Breeding sites include ponds, reservoirs, and slow-moving streams (Stebbins 1985; Petranka 1998).

Life History, Abundance, Activity, and Special Behaviors
The breeding season ranges from late December and early May, depending on location, and lasts 6-12 weeks. Breeding aggregations form primarily in ponds and lakes. Courtship involves amplexus of the female by the male who then rubs his head on hers. Eventually the male deposits a spermatophore on the substrate which the female picks up in her cloaca. Shortly after mating, the female lays her eggs in small round clusters containing 7-30 eggs. Time to hatching ranges from 2 weeks to 2 1/2 months, depending on water temperature. Diet items include earthworms, snails, slugs, insects, and conspecific eggs and larvae. See Petranka (1998) for references.

All species of Taricha possess the potent neurotoxin tetrodotoxin, that is used as an antipredator defense (Brodie et al. 1974). Tetrodotoxin is also harmful to humans (e.g. Petranka 1998).

When harassed, Taricha assume the “unken reflex” where the head is raised, the tail is turned up and held straight over the body, the limbs are extended, and the eyes are closed (Riemer 1958; Brodie 1977). This action exposes the bright aposomatic coloration found on the newt's belly. The exact pattern of this reflex is a species-specific character, distinguishable from sympatric T. granulosa, which curls the tip of the tail (Stebbins 1985; Petranka 1998).

Larva
Hatchlings are 10-14 mm total length. The larvae are pond type with bushy gills, balancer organs and a well-developed dorsal tail fin which extends forward to the shoulder region (Stebbins 1985; Petranka 1998). The dorsum of larvae is light yellow with two dark, narrow bands (Riemer 1958; Stebbins 1985).

Trends and Threats
Loss and degradation of stream habitats, and predation on eggs and larvae by introduced predators such as crayfish and mosquitofish, are a serious concern for populations of T. t. torosa in southern California (Jennings and Hayes 1994; Gamradt and Kats 1996). Road-kill is another large source of adult mortality. Furthermore, UV-B radiation has been shown to cause reduced hatching success (Anzalone et al. 1998; Blaustein et al. 1998).

The myriad of threats-- drought, wildfire, urbanization-- are taking their toll on populations in California, which is the subject of a photo essay both beautiful and heartbreaking by bioGraphics. Read the "Newt Normal" by Emily Sohn with photos by Anton Sorokin.

Possible reasons for amphibian decline

General habitat alteration and loss
Disturbance or death from vehicular traffic

Comments
Extremely warty newts found in many localities in San Diego County have been described as a separate subspecies, T. t. klauberi (Riemer 1958). This subspecies is not currently recognized because the presence of warts is thought to be caused by a pathogenic agent (Stebbins 1951; 1985).

Originally, the species was comprised of two allopatric subspecies based on geographic distribution and coloration. Both previous subspecies, T. t. torosa and T. t. sierrae, are recognized as a full species respectively (Kuchta 2007). Taricha sierrae, the Sierra newt, is reddish to chocolate brown dorsally and burnt orange to yellow below, and ranges along the western slopes of the Sierra Nevada south to Kern Co. (Stebbins 1985). Sierra Newts are found in habitats dominated by conifers (digger pines-blue oak and ponderosa pine communities) and breed in faster moving streams than Coast Range newts (Stebbins 1985; Petranka 1998).

UC Berkeley's Botanical Garden Director explains Newts mating onsite:

Deep Look into Newts

This species was featured as News of the Week on March 23, 2020:

Climate change is a growing threat to amphibians, in large part because of more frequent extreme heat and drought events. Using 10 years of survey and mark-recapture data, Bucciarelli et al. (2020) recently showed that populations of California newts (Taricha torosa) – a widespread species across California – have been impacted by extreme climate events in recent years, particularly in southern California where climate change is already more pronounced. Specifically, from 2008 to 2016, California newt body condition (body mass relative to newt length) decreased by 20% in response to extreme heat and drought. Newt survival also decreased over time in response to climate change. These effects were not seen in the northern part of the California newt’s range where climate change has been less pronounced. Even so, modeling suggests that climate change in northern California will be as severe or worse for newt populations. This work highlights the critical impact climate change will have on amphibian population declines and extinctions in the coming years, both on its own and also by exacerbating other serious threats like habitat loss and disease (Written by Max Lambert).

This species was featured as News of the Week on 2 August 2021:

Most amphibians secrete distasteful or toxic substances from their skin. Several groups wield toxins that can be lethal to other animals, or even to themselves. Animals can evolve resistance to toxins through mutations in proteins that prevent toxins from binding. Although these mutations can provide resistance, they often occur in important regions of a protein, such as those critical to nervous system functions. Thus, a problem arises: how can animals avoid the negative effects of mutations that also provide resistance? A pair of recent studies, one on the toxic salamanders Taricha (Gendreau et al. 2021) and another on frogs of the genus Leptodactylus (Mohammadi et al. 2021), which consume toxic toads, suggest that gene duplication is the key; one gene copy can help animals develop toxin resistance while the other copy maintains a functional nervous system. Both studies also show evidence for a fascinating molecular process known as gene conversion, wherein duplicate copies of one gene retain more similar-than-expected DNA sequences. During homologous recombination, two copies of a genome line up and exchange pieces of DNA; however, when two copies of a gene are near each other in the genome, the wrong genes can line up and exchange genetic material, maintaining genetic similarity between duplicate copies of a gene. In newts, gene conversion appears to have copied resistance-conferring mutations from one gene domain to another. In Leptodactylus frogs, strong natural selection countered the force of gene conversion, resulting in one toxin-resistant gene and one toxin-sensitive gene. How newts and frogs regulate the use of these different gene copies remains unknown and will be an exciting future research topic. (RT)

See other species accounts at www.californiaherps.com.

References

Anzalone, C. R., Kats, L. B., and Gordon, M. S. (1998). "Effects of solar UV-B radiation on embryonic development in Hyla cadaverina, Hyla regilla, and Taricha torosa." Conservation Biology, 12(3), 646-653.

Blaustein, A. R., Hays, J. B., Hoffmann, P. D., and Kiescecker, J. M. (1998). "The role of solar UVB radiation in amphibian population declines." Photochemistry and Photobiology, 67(SPEC. ISSUE), 11S.

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.

Collins, J. T. (1991). "A new taxonomic arrangement for some North American amphibians and reptiles." Herpetological Review, 22, 42-43.

Gamradt, S. C. and Kats, L. B. (1996). ''Effect of introduced crayfish and mosquitofish on California newts.'' Conservation Biology, 10(4), 1155-1162.

Jennings, M. R., and Hayes, M. P. (1994). ''Amphibian and reptile species of special concern in California.'' Final Report #8023 Submitted to the California Department of Fish and Game. California Department of Fish and Game, Sacramento, California..

Kuchta, S. R. (2007). ''Contact zones and species limits: hybridization between lineages of the California Newt, Taricha torosa, in the southern Sierra Nevada.'' Herpetologica, 63, 332-350.

Nussbaum, R. A., and Brodie, E. D., Jr. (1981). ''Taricha torosa (Rathke). California Newt.'' Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles, 273.1-273.4.

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

Riemer, W. J. (1958). "Variation and systematic relationships within the salamander genus Taricha." University of California Publications in Zoology, 56(3), 301-390.

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.

Storer, T. I. (1925). "A synopsis of the amphibia of California." University of California Publications in Zoology, 27, 1-342.

Species Account Citation: AmphibiaWeb 2023 Taricha torosa: California Newt <https://amphibiaweb.org/species/4290> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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