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| Taricha granulosa |
The rough-skinned newt (Taricha granulosa) is a North American newt known for its strong poison. The genus Taricha consists of three species and four subspecies of Western Newts (sometimes referred to as Pacific Newts) A newt is an Amphibian of the Salamandridae family order Urodela or Caudata, found in North America, Europe, and They are available in some places as pets, sometimes with names "Oregon newt" or "orange-bellied newt. " However the "Oregon newt" is more than likely a newt from California that looks similar. Oregon does not allow the commercial sales of these newts.
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Subspecies
T. granulosa is divided into two subspecies. Both have rough or granular skin, except for breeding males, which additionally exhibit swollen vents and cornified toe pads.
- The rough-skinned newt (T. g. granulosa) is light brown to brownish-black above with an orange or yellow belly. In some populations, the back has dark blotches. They are between 13 to 22 cm long. A centimetre ( American spelling: centimeter, symbol cm) is a unit of Length in the Metric system, equal to one hundredth
- The Crater Lake newt or Mazama newt (T. g. mazamae) is darker above and brighter below than T. g. granulosa and may also have dark blotches below. The validity of this subspecies, which is exclusive to the region of Crater Lake, Oregon, is disputed by some researchers because the newts on Gravina Island, Alaska, are very similar. Crater Lake is a Caldera Lake located in the US state of Oregon. Oregon ( is a state in the Pacific Northwest region of the United States. Gravina Island is an island in the Gravina Islands of the Alexander Archipelago in southeastern Alaska. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent
Toxicity
Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent. A newt is an Amphibian of the Salamandridae family order Urodela or Caudata, found in North America, Europe, and A toxin ( Greek:, toxikon, lit (poison for use on arrows is a Poisonous substance produced by living cells or organisms that is active at very low The genus Taricha consists of three species and four subspecies of Western Newts (sometimes referred to as Pacific Newts) One thirtieth of the toxin present in the skin of an average adult rough-skinned newt is sufficient to kill a healthy adult human. Toxicity is generally experienced only if the newt is ingested, although there are reports that some individuals experience skin irritation after dermal contact.
Toxin
The rough-skinned newt possesses tetrodotoxin, which in this species was formerly called tarichatoxin. Tetrodotoxin (anhydrotetrodotoxin 4-epitetrodotoxin tetrodonic acid TTX is a potent Neurotoxin with no known antidote which blocks Action potentials in Nerves This toxin binds to sodium channels in nerve cells and interferes with the normal flow of sodium ions in and out of the cell. This has the effect of inducing paralysis and death.
Toxin Resistance and Predation
Throughout much of the newt’s range, the common garter snake (Thamnophis sirtalis) has been observed to exhibit resistance to the tetrodotoxin produced in its skin. The common garter snake ( Thamnophis sirtalis) is a Snake indigenous to North America. While in principle the toxin binds to a tube shaped protein that acts as a sodium channel in the snake's nerve cells, researchers have identified a genetic disposition in several snake populations where the protein is configured in such a way as to hamper or prevent binding of the toxin. In each of these populations, the snakes exhibit resistance to the toxin and successfully prey upon the newts. Toxin resistant garter snakes are the only known animals today that can eat a T. granulosa newt and survive.
In evolutionary theory, the relationship between the rough-skinned newt and the common garter snake is considered an example of co-evolution. In a broad sense biological co-evolution is "the change of a biological object triggered by the change of a related object" The mutations in the snake’s genes that conferred resistance to the toxin have resulted in a selective pressure that favors newts which produce more potent levels of toxin. Increases in newt toxicity then apply a selective pressure favoring snakes with mutations conferring even greater resistance. This cycle of a predator and prey evolving to one another is sometimes termed an evolutionary arms race and has resulted in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator. In Evolutionary biology, an evolutionary arms race is an Evolutionary struggle between competing sets of co-evolving Genes that develop adaptations
Location
Habitats of rough-skinned newts are found throughout the west coast of the US. A habitat (which is Latin for "it inhabits" is an Ecological or environmental area that is inhabited by a particular Species. They are uncommon east of the Cascade Mountains though occasionally found (and considered exotic, and possibly artificially introduced) as far as Montana. The southern range extends to Santa Cruz, California and as far north as Alaska. Santa Cruz is the County seat and largest city of Santa Cruz County, California, United States. California ( is a US state on the West Coast of the United States, along the Pacific Ocean. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent [1]
See also
References
- ^ Natureserve Explorer
- Hammerson (2004). Salamander (orig from Persian: sām, "fire" and andarūn, "within" is the common name for a group of approximately 500 Species Subspecies California newts a species of toxic amphibian living in the United States are divided into two subspecies Sierra newt ( Taricha torosa sierrae The Red-bellied newt ( Taricha rivularis) is a Newt, native to coastal woodlands in northern California, which is terrestrial for most of Salamandridae is a family of Salamanders consisting of true salamanders and Newts There are currently 74 Species (with more expected spread all Taricha granulosa. 2006 IUCN Red List of Threatened Species. The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List) created in 1963 is the world's most comprehensive inventory of the global IUCN 2006. Retrieved on 12 May 2006.
- Taricha granulosa: Rough-skinned Newt. Caudata Culture. Retrieved on 2006-07-26. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 657 - Battle of Siffin. 811 - Battle of Pliska; Byzantine Emperor Nicephorus
- Geffeney, Shana L. , et al. “Evolutionary diversification of TTX-resistant sodium channels in a predatorÂ-prey interaction”. Nature 434 (2005): 759–763.
- Taricha granulosa granulosa – Rough-Skinned Newt. California Herps. Retrieved on 2006-12-10. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1041 - Empress Zoe of Byzantium elevates her adoptive son to the throne of the Eastern Roman Empire as Michael V
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