The Development and Etymology of Newt

About the Study

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 aquatic salamanders are considered newts, however. More than 100 known species of newts are found in North America, Europe, North Africa and Asia. Newts metamorphose through three distinct developmental life stages: aquatic larva, terrestrial juvenile (eft), and adult. Adult newts have lizard-like bodies and return to the water every year to breed, otherwise living in humid, cover-rich land habitats.

Newts are threatened by habitat loss, fragmentation and pollution. Several species are endangered, and at least one species, the Yunnan lake newt, has become extinct recently.

Etymology

The Old English name of the animal was efte, efeta (of unknown origin), resulting in Middle English eft; this word was transformed irregularly into euft, evete, or ewt (e). The initial "n" was added from the indefinite article "an" by provection (juncture loss) ("an eft" → "a n'eft" → ...) by the early 15th century. The form "newt" appears to have arisen as a dialectal variant of eft in Staffordshire, but entered Standard English by the Early Modern period. The regular form eft, now only used for newly metamorphosed specimens, survived alongside newt, especially in composition, the larva being called "water-eft" and the mature form "land-eft" well into the 18th century, but the simplex "eft" as equivalent to "water-eft" has been in use since at least the 17th century.

Dialectal English and Scots also has the word ask (also awsk, esk in Scots) used for both newts and wall lizards, from Old English āþexe, from Proto-Germanic agiþahsijǭ, literally "lizard-badger" or "distaff-like lizard" (compare German Eidechse and Echse, both lizard; agi- is ultimately cognate with Greek ὄφις "snake," from Proto-Indo-European). Latin had the name stellio for a type of spotted newt, now used for species of the genus Stellagama. Ancient Greek had the name κορδύλος, presumably for the water newt (immature newt, eft).German has Molch, from Middle High German mol, wikt:olm, like the English term of unknown etymology.

Newts are also known as Tritones (viz., named for the mythological Triton) in historical literature, and "triton" remains in use as common name in some Romance languages, such as Romanian, but as well as in Greek, Russian, and Bulgarian. The systematic name Tritones was introduced alongside Pleurodelinae by Tschudi in 1838, based on the type genus named Triton by Laurenti in 1768. Laurenti's Triton was renamed to Triturus ("Triton-tail") by Rafinesque in 1815. Tschudi's Pleurodelinae is based on the type genus Pleurodeles (ribbed newt) named by Michahelles in 1830 (the name meaning "having prominent ribs," formed from πλευρά "ribs" and δῆλος "conspicuous").

Development

The main breeding season for newts (in the Northern Hemisphere) is in June and July. A single newt female can produce hundreds of eggs. For instance, the warty newt can produce 200–300 eggs. After courtship rituals of varying complexity, which take place in ponds or slow-moving streams, the male newt transfers a spermatophore, which is taken up by the female. Fertilized eggs are laid singly and are usually attached to aquatic plants. This distinguishes them from the free-floating eggs of frogs or toads, which are laid in clumps or in strings. Plant leaves are usually folded over and attached to the eggs to protect them. The larvae, which resemble fish fry but are distinguished by their feathery external gills, hatch out in about three weeks. After hatching, they eat algae, small invertebrates, or other amphibian larvae.

During the subsequent few months, the larvae undergo metamorphosis, during which they develop legs, and the gills are absorbed and replaced by air-breathing lungs. Some species, such as the North American newts, also become more brightly colored during this phase. Once fully metamorphosed, they leave the water and live a terrestrial life, when they are known as "efts." Only when the eft reaches adulthood will the North American species return to live in water, rarely venturing back onto the land. Conversely, most European species live their adult lives on land and only visit water to breed