Eastern Newt, Broken-Striped Newt, Central Newt, Peninsula Newt, Red Spotted Newt
© 2011 Gary Sargent (1 of 150)
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Canada, United States
U.S. state distribution from AmphibiaWeb's database: Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Virginia, Vermont, Wisconsin, West Virginia
Canadian province distribution from AmphibiaWeb's database: New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec
Life History, Abundance, Activity, and Special Behaviors
N. viridescens has a complex life cycle, with four distinct stages: egg, aquatic larva, red eft (terrestrial juvenile), and adult (Petranka 1998). The breeding season lasts from late winter to early spring (Behler and King 1996). A single batch of 200-400 eggs is typically laid by the females on submerged vegetation, with an incubation period of 3-8 weeks (Behler and King 1996). On hatching, a larva measures about 8 mm in size (Behler and King 1996). Larvae may develop along one of three possible pathways: metamorphosis via a terrestrial juvenile (eft) stage to an aquatic lunged adult; metamorphosis directly to an aquatic lunged adult; or paedomorphosis (maturation directly to an aquatic gilled adult with no metamorphosis) (Takahashi 2008; Takahashi and Parris 2008). Generally, following metamorphosis from the aquatic larval stage, juveniles disperse away from their home ponds and spend three to seven years as terrestrial red efts (Forester and Lykens 1991). Efts return to aquatic habitats to reproduce when they become sexually mature, and undergo a second transformation to a more aquatic adult form during breeding season. Aquatic adults become green in coloration, have smoother, mucous skin and develop large tail fins, particularly pronounced in breeding males (Gage 1891; Gill 1978a). The change from terrestrial phenotype to aquatic phenotype may take days to weeks (Grayson and Wilbur 2009). After breeding season is over, adults may remain aquatic or may return to terrestrial habitat; if they disperse terrestrially, the skin texture and color changes and the tail fin reduces in size (Brimley 1921; Walters and Greenwald 1977; Davis and Grayson 2007).
Terrestrial newts can migrate across both open and forested habitat (Healy 1973); the use of fluorescent tracking powder showed that efts meandered more while adult newts were found to make more linear trails away from the pond (Roe and Grayson 2008). After periods of rain, concentrations of efts in forest regions may be high (Behler and King 1996). Terrestrial efts and adults make use of a variety of surface or near-surface microhabitats, mostly under forest debris such as leaves, logs, and branches; they are never found in subterranean habitat or mammal burrows (Roe and Grayson 2008). Emergence from refuges and continued movement depend on having a moist surface environment (Roe and Grayson 2008). Distance traveled by efts or adults depended on the humidity and precipitation levels of the previous day (Roe and Grayson 2008). Some postbreeding newts were found to travel over 50 m in 24 hours (Roe and Grayson 2008). When out and active, individuals tracked by using fluorescent powder were often found to have climbed up ferns and logs, probably to forage (Roe and Grayson 2008).
The adult diet includes worms, insects, small crustaceans, amphibian eggs and larvae (Behler and King 1996). Feeding occurs year-round (Morgan and Grierson 1932). Adults were found to be capable of consuming an average of 316 mosquito larvae per day (DuRant and Hopkins 2008).
Cutaneous secretions of toxic substances (tetrodotoxin and its analogues 6-epiTTX and 11-oxoTTX) serve as a defense mechanism from potential predators (Webster 1960; Brodie 1968; Hurlburt 1970; Pough 1971; Brandon et al. 1979; Brodie and Formanowicz 1981; Shure et al. 1989). Although the bright coloration of juveniles (red efts) is presumed to be aposematic, one study supported that conclusion by finding that efts were more toxic than non-aposematic adults (Wakely et al. 1966), but a different study found that efts and non-aposematic adults were equally toxic (Yotsu-Yamashita and Mebs 2003). It is thought that the nontoxic plethodontid salamander Pseudotriton ruber, which is bright red, may be mimicking the coloration of efts (Howard and Brodie 1971; Huheey and Brandon 1974).
Possible reasons for amphibian decline
General habitat alteration and loss
Subspecies include N. v. dorsalis, N. v. louisianesis, N. v. piaropicola, and N. v. viridescens (Behler and King 1996) . However, phylogenetic analyses have identified clades that do not correspond to the current subspecies designations (Takahashi 2008).
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Originally submitted by: Kevin Gin (first posted 2003-11-25)
Edited by: Kellie Whittaker (2011-01-17)
Species Account Citation: AmphibiaWeb 2011 Notophthalmus viridescens: Eastern Newt <https://amphibiaweb.org/species/4265> University of California, Berkeley, CA, USA. Accessed Aug 13, 2022.
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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 13 Aug 2022.
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