Newt

Newts
Smooth Newt (Triturus vulgaris)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Lissamphibia Order: Caudata/Urodela Family: Salamandridae

Newts (also called efts when terrestrial) are an informal grouping of salamanders within the Salamandridae family that may have rough-textured skin when terrestrial, unlike other salamanders, and whose rib or costal grooves along the sides of the body usually are not distinct. Newts often are brightly colored.

The family Salamandridae is informally divided into two groups, the newts and the "true salamanders" (Larson et al. 2007). True salamanders are general considered to include the genera Salamandra, Lyciasalamandra, Clioglossa, and Mertensiella, while newts include all remaining extant genera (Larson et al. 2007). While both groups have aquatic larva, adults of true salamanders are highly terrestrial, whereas the newts are at least partly aquatic and some are entirely aquatic (Larson et al. 2007). Terrestrial newts also must return to the water to reproduce.

Characteristics

Newts are not a formal taxa. Unlike all other salamanders (order Caudata), newts have rough-textured skin that is not slimy (Larson et al. 2007). Like most salamandrids, they have a biphasic life cycle with aquatic larvae, with four pairs of gills slits and large external gills, and undergo metamorphosis into adults that may be terrestrial or aquatic and have legs that are relatively long, prominent, and robust (Larson et al. 2007). However, some newts have a complex life cycle, with two metamorphoses and three development stages, proceeding from aquatic larva, a terrestrial juvenile ("red eft"), and a secondarily aquatic adult (Larson et al. 2007).

All newts have aquatic larvae and some are strictly aquatic as adults, while others are terrestrial as adults, but return to ponds or streams to reproduce (Larson et al. 2007).

Alpine newt larva

Newts can take several years to reach sexual maturity. A typical life cycle is as follows. For many, their main breeding season is between February and June. They hatch as tadpoles from eggs laid in ponds or slow-moving streams. In the case of triturus even brackish water is used, but most species are more selective. Then, they undergo metamorphosis, during which they commonly leave the water. Some return to the water to live out their adult lives. During the time right after metamorphosis, many North American newt species go through a phase called the eft phase. In some cases, their skin changes color, but efts always live their life on land, almost never seen in the water. Only when the eft reaches adulthood will it begin to live its life in a more aquatic fashion, and may rarely venture onto land. Many newts will live out their adulthood on land and only visit water to breed.

Salamandrids all have toxic skin secretions and newts are highly poisonous in all stages of their life cycle (Larson et al. 2007). This serves as a defense mechanism against predators. In order to cause harm, the toxins have to enter the body by being ingested or entering a break in the skin. Taricha newts of western North America are particularly toxic; the Rough-skinned Newt (Taricha granulosa) of the Pacific Northwest produces more than enough tetrodotoxin to kill an adult human foolish enough to swallow a newt.

Newts have the ability to regenerate limbs, eyes, spinal cords, hearts, intestines, and upper and lower jaws. The cells at the site of the injury have the ability to de-differentiate, reproduce rapidly, and differentiate again to create a new limb or organ. One theory is that the de-differentiated cells are related to tumor cells since chemicals that produce tumors in other animals will produce additional limbs in newts (Odelberg 2007).

Distribution

Newts are widespread in distribution, covering much of Europe and with species in North America, China, Laos, Vietnam, Middle East and northwestern Africa (Larson et al. 2007).

The three common European genera are the crested newts (Triturus sp.), the European newts (Tylotriton sp.), the banded newts (Ommatotriton sp.), and some individuals such as the Spanish Ribbed Newt (Plurodeles waltl), the largest newt, and the Alpine newt (Mesotriton alpestris).

In North America, there are the Eastern newts (Notophthalmus sp.), of which the red-spotted newt (Notophthalmus viridescens) is the most abundant species, but it is limited to the area east of the Rocky Mountains. The three species of coastal, or Western newts are the red-bellied newt, the California Newt, and the rough-skinned newt, all of which belong to the genus Taricha, which is confined to the area west of the Rockies.

In Southeast Asia and Japan, species commonly encountered in the pet trade include the firebelly newts (Cynops sp.), the paddletail newts (Pachytriton sp.), the crocodile newts (Tylototriton sp.), and the warty newts (Paramesotriton sp.). In the Middle East there are the Middle Eastern newts (Neurergus sp.).

Etymology

The oldest form of the name is eft, which is still used for newly metamorphosed juveniles, but according to the Oxford English Dictionary it changed for unknown reasons first to euft and then to ewt. For some time it remained as an ewt, but the "n" from the indefinite article (an) shifted to form a newt. See A, an for other examples.

Newts in popular culture

• The P.G. Wodehouse character Gussie Fink-Nottle, a friend of Bertie Wooster, has a fascination with newts.
• In 1936, Czech science-fiction writer Karel Čapek wrote an internationally-acclaimed novel called War With the Newts about the discovery of a species of intelligent newts in an island close to Indonesia.
• In Monty Python and the Holy Grail a peasant claims that a suspected witch turned him into a newt. He got better.
• The witches in Macbeth include "Eye of newt, and toe of frog, Wool of bat, and tongue of dog" along with many other repulsive ingredients in a recipe for their potion, but the "eye of newt" stands foremost in the popular imagination as the archetypical arcane spell ingredient.
• In the film Aliens the character played by Carrie Henn is nicknamed Newt.
• In the anime film Spirited Away (Sen to Chihiro no kamikakushi), grilled newt is a highly sought-after delicacy in the Aburaya bath house.
• In The Animals of Farthing Wood, the Newt family are among the animals who undertake the dangerous journey to White Deer Park.
• In the Nickelodeon cartoon Catscratch, the character Waffle owns many pet newts.
• In the Harry Potter series by J.K. Rowling the students take N.E.W.T.'s which are the exams for the 7th years at Hogwarts. McGonagall also offers Harry "ginger newts" in book five.
• The 6.10 version of the Linux distribution Ubuntu is codenamed "Edgy Eft".
• In the novel Matilda by Roald Dahl, Lavender, Matilda's good friend, uses a newt to play a prank on the head teacher Miss Trunchbull.

Notes

• Griffiths, R. 1996. Newts and Salamanders of Europe. London: Academic Press. ISBN 012303955X.
• Larson, A., D. Wake, and T. Devitt. 2007. Salamandridae. Newts and "true salamanders". Version 24 (under construction). Tree of Life Web Project. Retrieved March 31, 2007.

• Odelberg, S. 2007. Research. Molecular Biology Programm Bioscience Graduate Studies, University of Utah. Retrieved January 24, 2007.

External references

• Caudata Culture. Retrieved March 31, 2007.
• Livingunderworld.org. Retrieved March 31, 2007.

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