red eft

n.
The bright red terrestrial stage in the life cycle of a newt (Notophthalmus viridescens) of the eastern United States.

Notophthalmus viridescens

TAXONOMY

Triturus viridescens Rafinesque, 1820, Lake Champlain, New York, United States.

OTHER COMMON NAMES

English: Red-spotted newt; French: Tritón vert.

PHYSICAL CHARACTERISTICS

Green above and yellow on the belly, the body is decorated with a number of bright red spots, each ringed in black. The tail is one-half the total length of the newt, which is up to 4.8 in (12 cm). The tail of aquatic adults bears a large fin, which is larger on males than on females.

DISTRIBUTION

Eastern North America. The black-spotted newt (Notophthalmus meridionalis) occurs only in coastal areas of Texas and Mexico. The striped newt (N. perstriatus) is confined to southern Georgia and northern Florida.

HABITAT

The eastern newt lives and breeds in all kinds of permanent and semipermanent water.

BEHAVIOR

In its juvenile stage, which lasts one to four years, the eastern newt acquires a vivid red coloration, is highly toxic, and is called a red eft. This newt has the most complex and variable life history of any amphibian. It typically goes through four stages: egg, aquatic larva, eft, and terrestrial adult, returning annually to water to breed. There is much variation in this basic pattern, however, from one part of the range to another. Some populations have no eft stage. In other populations, some adults enter water at maturity but then do not leave. In other populations, some adults are never terrestrial but are paedomorphic. Adult eastern newts are only mildly toxic in comparison with red efts. When attacked, adults exhibit the unken reflex whereby they twist themselves into a circle to expose a bright yellow belly. Paedomorphosis is widespread in this species, in which the red and black markings take the form of stripes.

FEEDING ECOLOGY AND DIET

The eastern newt feeds on a variety of small invertebrates and on frog tadpoles.

REPRODUCTIVE BIOLOGY

Mating behavior is complex and variable. In the breeding season, males develop large and powerful hind limbs that have horny patches on the inner surfaces. Males use the limbs to capture females in a remarkably rapid movement. The male holds the female in amplexus for a long time, stimulating her by rubbing large glands on his head over her snout. When the female is responsive, the male dismounts and deposits a spermatophore. Sometimes a quicker form of mating is used in which the male quickly "tests" the female by waving his tail in front of her. If the female responds, the male proceeds immediately to spermatophore deposition. The female lays eggs singly, attaching them to water weeds. It is thought that clutch size is 200–300 eggs.

CONSERVATION STATUS

Not threatened. The eastern newt is by far the most widespread of the three species in this genus, although it has declined over much of its range as a result of habitat loss and pollution.

SIGNIFICANCE TO HUMANS

None known.

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The noun has one meaning:

Meaning #1: red terrestrial form of a common North American newt
  Synonym: Notophthalmus viridescens

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