The California newt or orange-bellied newt (''Taricha torosa''), is a species of

newt A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aqua ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, in the

Western United States The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...

. Its adult length can range from . Its skin produces the potent toxin

tetrodotoxin Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovere ...

Subspecies

''Taricha torosa'' was divided into two subspecies until 2007, when it was determined that the Sierra and coastal populations represent distinct evolutionary lineages. The former subspecies ''Taricha torosa sierrae'' was elevated to full species level and it is now known as ''Taricha sierrae'', the

Sierra newt The Sierra newt (''Taricha sierrae'') is a newt found west of the Sierra Nevada, from Shasta county to Tulare County, in California, Western North America. Its adult length can range from . Its skin produces a potent toxin. Subspecies The S ...

. ''Taricha torosa torosa'' has been retired and now all coastal populations are simply known as ''Taricha torosa'', the California newt.

Range and habitat

California newts reside in the coastal counties of

and in the southern

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

and occupy a diverse array of habitats found near the small ponds and creeks where they breed, including woodlands and chaparral.

Description

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 The rough-skinned newt or roughskin newt (''Taricha granulosa'') is a North American newt known for the strong toxin exuded from its skin. Appearance A stocky newt with rounded snout, it ranges from light brown to olive or brownish-black on ...

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 The red-bellied newt (''Taricha rivularis'') is a newt that is native to coastal woodlands in northern California and is terrestrial for most of its life. Description When full grown, the red-bellied newt measures between from its nose to its v ...

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

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 A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores ...

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 Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

stream, varying in depth from about . 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. 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.

Toxicity and predation

Like other genus ''

Taricha The genus ''Taricha'' consists of four species of highly toxic newts in the family Salamandridae. Their common name is Pacific newts, sometimes also western newts or roughskin newts. The four species within this genus are the California newt, t ...

'' members, the glands in the skin of ''Taricha torosa'' secrete the potent neurotoxin

, which is hundreds of times more toxic than

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...

. 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 Garter snake is a common name for generally harmless, small to medium-sized snakes belonging to the genus ''Thamnophis'' in the family Colubridae. Native to North and Central America, species in the genus ''Thamnophis'' can be found from the sub ...

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 In evolutionary biology, an evolutionary arms race is an ongoing struggle between competing sets of co-evolving genes, phenotypic and behavioral traits that develop escalating adaptations and counter-adaptations against each other, resembling an ...

has resulted in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator.

Diet

Earthworms,

snails A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

slugs Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a sma ...

woodlice A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood. ...

, bloodworms,

mosquito larvae Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "lit ...

crickets Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 8 ...

, and other invertebrates are among the California newt's prey. Adult newts have also been known to cannibalize their own eggs and larvae.https://animaldiversity.org/accounts/Taricha_torosa/ In the Sierra Nevada, the newt will also consume

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salmoni ...

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.

Conservation status

''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 The western Mosquitofish (''Gambusia affinis'') is a North American freshwater fish, also known commonly, if ambiguously, as simply Mosquitofish or by its generic name, ''Gambusia'', or by the common name gambezi. Its sister species, the easte ...

'') and red swamp crayfish (''

Procambarus clarkii ''Procambarus clarkii'', known variously as the red swamp crayfish, Louisiana crawfish or mudbug, is a species of cambarid crayfish native to freshwater bodies of northern Mexico, and southern and southeastern United States, but also introduce ...

'') have caused the greatest reduction in newt populations. Introduced as fish bait and stock pond prey, red swamp

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

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.

References

* Database entry includes a range map and justification for why this species is of least concern
San Diego Natural History Museum

External links

''Taricha torosa'' (Rathke, 1833)
Amphibian Species of the World. American Museum of Natural History

– ''California newt facts''.

– ''with video''.
Caudata.org: Culture of California newts (''Taricha torosa'')
– ''guide to identifying species and keeping as a pet''. {{Taxonbar, from=Q1358580 Newts Amphibians of the United States

Newt A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aqua ...

Fauna of the Sierra Nevada (United States) Fauna of the San Francisco Bay Area Natural history of the California Coast Ranges Natural history of the Peninsular Ranges Natural history of the Santa Monica Mountains Natural history of the Transverse Ranges Taxa named by Martin Rathke Amphibians described in 1833