The California Newt Taricha torosa is one of 5 members of the newt family (Salamandridae) which inhabit California. The California Newt is primarily located on the Coastal Range of California from Humbolt County to the Mexican border. Other isolated populations are also located in California, along the western slope of the Sierra Nevada mountain range (Petranka, 1998; Stebbins 1985; Dudek and Assoc., Inc. 2000).
Biogeographic Regions: nearctic (Native )
The California Newt of the northern population prefers the mesic forests as opposed to the southern population newts which prefer a drier climate (Petranka, 1998).
Aquatic Biomes: lakes and ponds; rivers and streams
Average lifespan
Status: captivity: 21.8 years.
The adult California Newt is typically 12.5-20 cm (4.9-7.8 inches) in total length with males slightly larger than females. California Newts vary in color from a yellowish brown to a dark brown warty textured skin dorsally and a pale yellow to orange bottom on its ventral side. The aquatic larvae have a black stripe on either side of their dorsal fins and have gills in younger stages of development. They have large eyes that protrude beyond the edge of their head and light colored lower eyelids. (Petranka, 1998; Stebbins & Cohen, 1998).
Other Physical Features: ectothermic ; bilateral symmetry
The diet of an adult California Newt consists of earthworms, snails, slugs, and sowbugs. Adult newts have also been known to cannibalize their own eggs and larvae. There is little known about the diets of the California Newt during the larvae stage.
The California Newt has an adhesive texture to its tongue and projects it out to capture its prey.(Petranka, 1998; Dudek and Assoc., Inc. 2000, Deban 1996).
Development - Life Cycle: metamorphosis
The California Newt is not currently listed as an endangered species but there is to be a significant problem in the Santa Monica Mountains with non-native crayfish (Procambarus clarkii) and mosquitofish (Gambusia affiinis) feeding on the eggs and larvae of the California Newt. (Petranka, 1998).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
There are 2 recognized subspecies of Taricha torosa . The Coast Range Newt Taricha torosa torosa occupies the Coast range while the Sierra Newt, Taricha torosa sierrae is found in the Sierra Nevada mountain ranges (Petranka, 1998; Stebbins, 1985).
Mating for the California Newt takes place from December to early May. The California Newt often migrates back to breed where they developed as larvae. Courtship of the California Newt involves a dance ritual in which the male mounts the female and rubs his chin over her nose and flutters his tail. After approximately an hour the male dismounts and leaves a spermatophore, in the form of a small mound, for the female move over and retrieve with her cloaca. The female California Newt will lay their eggs in ponds, lakes, and slow moving streams in water typically not deeper than 15 cm (5 inches). They lay from 7-30 eggs (approximately 1.9-2.8mm in diameter), attached to exposed roots or unattached on the bottom. The eggs are protected by a gel-like membrane that is toxic. The incubation period is usually 14-21 days and often longer depending on weather conditions. The size and amount of time in the larvae stage depends on the food sources and environmental conditions of their habitat (Petranka, 1998; Duellman, 1986).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate)
The California newt or orange-bellied newt (Taricha torosa), is a species of newt endemic to California, in the Western United States. Its adult length can range from 5 to 8 in (13 to 20 cm).[2] Its skin produces the potent toxin tetrodotoxin.[3]
Taricha torosa was divided into two subspecies until 2007, when it was determined that the Sierra and coastal populations represent distinct evolutionary lineages.[4] The former subspecies Taricha torosa sierrae was elevated to full species level and it is now known as Taricha sierrae, the Sierra newt. Taricha torosa torosa has been retired and now all coastal populations are simply known as Taricha torosa, the California newt.
California newts reside in the coastal counties of California and in the southern Sierra Nevada and occupy a diverse array of habitats found near the small ponds and creeks where they breed, including woodlands and chaparral.[5][6]
The California newt has warty, slate-gray skin on its back and bright orange-yellow skin underneath. It is very similar in appearance to the rough-skinned newt and they are often indistinguishable without dissection, but in general, the California newt has orange skin around the bottom of its eye while the Rough-skinned has gray skin at the bottom of its eye. The California newt also has eyes that protrude beyond the edge of the jaw line when viewed from above, while the eyes of the rough-skinned do not protrude, giving its head a more bullet-like appearance. The red-bellied newt is also similar but has dark irises vs. yellow in the California newt, more red coloration underneath, and a dark band across the vent that is lacking in the California newt..Newts are amphibians. They are related to salamanders (in a subfamily called Pleurodelinae). They live in North America, Europe and Asia. Their skin tends to be rougher than the skin of salamanders.
Reproduction occurs generally between December and early May. Typically, the adult newts will return to the pool in which they hatched. After a mating dance, the male mounts the female and rubs his chin on her nose. He then attaches a spermatophore to the substrate, which she will retrieve into her cloaca.
The egg mass released by the female contains between seven and 30 eggs, and is roughly the consistency of a thick gelatin dessert. Typically, the egg masses are attached to stream plant roots or to rocky crevices in small pools of slow-moving water, but they have also been known to be attached to underwater rocks or leaf debris. While shallow in a wide sense, these pools are rather deep relative to the average depth of a Southern California stream, varying in depth from about 1–2 metres (3.3–6.6 ft).
Adult newts typically leave the pools shortly after breeding has concluded, however, some adults may remain in the pools for an additional few months to feed.[7] Larvae hatch sometime in early to midsummer, depending on local water temperature. Larvae are difficult to find in streams, as they blend in well with the sandy bottom, to which they usually stay close.
Like other genus Taricha members, the glands in the skin of Taricha torosa secrete the potent neurotoxin tetrodotoxin, which is hundreds of times more toxic than cyanide. This is the same toxin found in pufferfish and harlequin frogs. Researchers believe bacteria synthesize tetrodotoxin, and the animals that employ the neurotoxin acquire it through consumption of these bacteria. This neurotoxin is strong enough to kill most vertebrates, including humans.
Due to their toxicity, California newts have few natural predators. Garter snakes are the most common, and some species have developed a genetic resistance to tetrodotoxin. The mutations in the snake's genes that conferred resistance to the toxin have resulted in a selective pressure that favors newts that produce more potent levels of toxin. Increases in newt toxicity then apply a selective pressure favoring snakes with mutations conferring even greater resistance. This evolutionary arms race has resulted in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator.[8][9][10][11]
Earthworms, snails, slugs, woodlice, bloodworms, mosquito larvae, crickets, and other invertebrates are among the California newt's prey. Adult newts have also been known to cannibalize their own eggs and larvae.[12] In the Sierra Nevada, the newt will also consume trout eggs. In an aquarium habitat, earthworms provide the newt with all necessary nutrients. Other natural prey items would benefit the captive newt. Pellets tend to be inappropriate for terrestrial caudates, and fish food should be avoided completely.
Taricha torosa, the California newt, is currently a California Special Concern species (DFG-CSC). Some populations have been greatly reduced in southern California coastal streams due to the introduction of non-native, invasive species and human habitation. The mosquitofish (Gambusia affinis) and red swamp crayfish (Procambarus clarkii) have caused the greatest reduction in newt populations.[13]
Introduced as fish bait and stock pond prey, red swamp crayfish are an incredibly aggressive, prolific, and stalwart species that will prey upon newt larvae and egg masses. The crayfish will also disrupt newt breeding via competition for space during the summer mating season and physically antagonizing adults. Crayfish will typically maul the adult newts with their claws, and subsequent infection can lead to death. Taricha torosa that are present in streams with introduced crayfish often sport tails with several notches removed.[13]
The California newt or orange-bellied newt (Taricha torosa), is a species of newt endemic to California, in the Western United States. Its adult length can range from 5 to 8 in (13 to 20 cm). Its skin produces the potent toxin tetrodotoxin.
