Taricha
Encyclopedia
The genus Taricha consists of three species and four subspecies of Western Newts (sometimes referred to as Pacific Newts). All newts are part of the family Salamandridae
. The three species within this genus are the California Newt
, the Rough-Skinned Newt
, and the Red Bellied Newt, all of which are found on the west coast of the USA.
(T. granulosa) and the California Newt
(T. torosa) share several characteristics. Both are light brown to black on the upper body and orange to yellow on the underbelly. They have "pebbly" skin that is not slimy and they may grow to a length of 8 inches, which is large for a salamander
. However, there are a few characteristics to tell them apart. Rough-skinned Newts have small eyes with dark lower eyelids, while California Newts have large eyes and light lower eyelids. Also, rough-skinned newts' upper teeth form a V shape, while those of the California newt form a Y shape. However, this is difficult to ascertain on a living specimen.
The Red-bellied Newt
(T. rivularis) is brown on the upper body with a red underbelly, has grainy skin, and grows to between 5.5 and 7.5 inches. It can be distinguished from other coastal newts, not only by its red belly, but also by the lack of yellow in its eyes. Breeding males develop smooth skin and a flattened tail.
and mosquito larvae. Most predators associate bright colors with poison (called aposematism
) and therefore, if attacked, the newt will take up a defensive position, showing off the bright underbelly. If the predator is not deterred by this display the newt may be its last meal. Newts of this genus are primarily nocturnal and may be either fully aquatic
or semi-aquatic. None are fully terrestrial
as they must enter the water to breed. Juvenile newts, which are known as "eft
s", are primarily terrestrial until they reach sexual maturity
.
(TTX), one of the most potent toxins known to science. However, toxicity varies between species and between populations within a species. In general, the Rough-skinned Newt
(T. granulosa) is the most toxic species. Rough-Skinned newts from populations in Northern Oregon are more toxic than those from California
and Washington. Those on Vancouver Island
, in British Columbia
, possess little or no TTX.
Taricha can be lethal to humans if ingested and at least one human fatality occurred in Oregon from eating a Rough-skinned Newt. Eastern newt
s of the genus Notophthalmus (=Diemictylus of earlier authors) also secrete TTX, but in lesser amounts. When handling Taricha the toxins should not be allowed to come in contact with broken skin or mucous membrane
s. Proper hand washing after handling should prevent any problems with ingestion of TTX (as well as infection from Salmonella
which newts may carry), though, some individuals are known to be allergic to skin contact with the toxin.
Salamandridae
Salamandridae is a family of salamanders consisting of true salamanders and newts. Currently, 74 species have been identified in the northern hemisphere - Europe, Asia, the northern tip of Africa and North America...
. The three species within this genus are the California Newt
California Newt
The California newt is a newt. It is also referred to as the orange bellied newt. They can grow to be in length.- Physical description :T. torosa adult length can range from to...
, the Rough-Skinned Newt
Rough-skinned Newt
The rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...
, and the Red Bellied Newt, all of which are found on the west coast of the USA.
Species
Genus Taricha (Western Newts / Pacific Newts) - 3 species- Rough-skinned NewtRough-skinned NewtThe rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...
(Taricha granulosa) - Red-bellied NewtRed-bellied NewtThe Red-bellied newt is a newt, native to coastal woodlands in northern California, which is terrestrial for most of its life.-Physical description:...
(Taricha rivularis) - California NewtCalifornia NewtThe California newt is a newt. It is also referred to as the orange bellied newt. They can grow to be in length.- Physical description :T. torosa adult length can range from to...
(Taricha torosa)
Differentiating between species
The Rough-skinned NewtRough-skinned Newt
The rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...
(T. granulosa) and the California Newt
California Newt
The California newt is a newt. It is also referred to as the orange bellied newt. They can grow to be in length.- Physical description :T. torosa adult length can range from to...
(T. torosa) share several characteristics. Both are light brown to black on the upper body and orange to yellow on the underbelly. They have "pebbly" skin that is not slimy and they may grow to a length of 8 inches, which is large for a salamander
Salamander
Salamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...
. However, there are a few characteristics to tell them apart. Rough-skinned Newts have small eyes with dark lower eyelids, while California Newts have large eyes and light lower eyelids. Also, rough-skinned newts' upper teeth form a V shape, while those of the California newt form a Y shape. However, this is difficult to ascertain on a living specimen.
The Red-bellied Newt
Red-bellied Newt
The Red-bellied newt is a newt, native to coastal woodlands in northern California, which is terrestrial for most of its life.-Physical description:...
(T. rivularis) is brown on the upper body with a red underbelly, has grainy skin, and grows to between 5.5 and 7.5 inches. It can be distinguished from other coastal newts, not only by its red belly, but also by the lack of yellow in its eyes. Breeding males develop smooth skin and a flattened tail.
Behavior
Taricha spp. eat a diet largely consisting of invertebrates such as Blood wormsMidge
A midge is a very small, two-winged flying insect. "Midge" may also refer to:-Real:* Midge Costanza , American politician* Mildred Gillars , aka "Midge", American broadcaster of Nazi propaganda during World War II...
and mosquito larvae. Most predators associate bright colors with poison (called aposematism
Aposematism
Aposematism , perhaps most commonly known in the context of warning colouration, describes a family of antipredator adaptations where a warning signal is associated with the unprofitability of a prey item to potential predators...
) and therefore, if attacked, the newt will take up a defensive position, showing off the bright underbelly. If the predator is not deterred by this display the newt may be its last meal. Newts of this genus are primarily nocturnal and may be either fully aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
or semi-aquatic. None are fully terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
as they must enter the water to breed. Juvenile newts, which are known as "eft
EFT
-Science:* Eft, the terrestrial juvenile phase of a newt* Effective field theory, an approximate theory to describe physical phenomena* Ewing family of tumors, a group of cancers-Technology:* Electrical Fast Transient, see Transient...
s", are primarily terrestrial until they reach sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
.
Toxicity
All species within the genus Taricha possess the biotoxin tetrodotoxinTetrodotoxin
Tetrodotoxin, also known as "tetrodox" and frequently abbreviated as TTX, sometimes colloquially referred to as "zombie powder" by those who practice Vodou, is a potent neurotoxin with no known antidote. There have been successful tests of a possible antidote in mice, but further tests must be...
(TTX), one of the most potent toxins known to science. However, toxicity varies between species and between populations within a species. In general, the Rough-skinned Newt
Rough-skinned Newt
The rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...
(T. granulosa) is the most toxic species. Rough-Skinned newts from populations in Northern Oregon are more toxic than those from California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and Washington. Those on Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
, in British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, possess little or no TTX.
Taricha can be lethal to humans if ingested and at least one human fatality occurred in Oregon from eating a Rough-skinned Newt. Eastern newt
Eastern Newt
The Eastern Newt or Red-spotted Newt is a common salamander of eastern North America. Eastern newts dwell in wet forests with small lakes or ponds. They can coexist in an aquatic environment with fish, however, their skin secretes a poisonous substance when the newt is threatened or injured...
s of the genus Notophthalmus (=Diemictylus of earlier authors) also secrete TTX, but in lesser amounts. When handling Taricha the toxins should not be allowed to come in contact with broken skin or mucous membrane
Mucous membrane
The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
s. Proper hand washing after handling should prevent any problems with ingestion of TTX (as well as infection from Salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
which newts may carry), though, some individuals are known to be allergic to skin contact with the toxin.