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Brief Summary

    Eastern newt: Brief Summary
    provided by wikipedia

    The eastern newt (Notophthalmus viridescens) is a common newt of eastern North America. It frequents small lakes, ponds, and streams or near-by wet forests. The eastern newt produces tetrodotoxin which makes the species unpalatable to predatory fish and crayfish. It has a lifespan of 12 to 15 years in the wild, and may grow to five inches in length. These animals are common aquarium pets, being either collected from the wild or sold commercially. The striking bright orange juvenile stage, which is land-dwelling, is known as a red eft. Some sources blend the general name of the species and that of the red-spotted newt subspecies into eastern red-spotted newt (although there is no "western" one).

Comprehensive Description

    Description
    provided by AmphibiaWeb text

    This salamander ranges from 6.5 to 14 cm in length. Terrestrial N. viridescens ("red efts") are juveniles and thus generally smaller in size (3.5 to 8.6 cm in length); efts are orange-red to reddish-brown in color. Aquatic adults are generally green with two dorsal rows of red to orange spots; the dorsum may also be yellow-brown, olive-green, or dark brown. The venter is yellow. Breeding aquatic males have brighter and redder spots than females (Davis and Grayson 2008), as well as enlarged hind legs, swollen vents and a broadly keeled tail, and black keratinized structures on the inner thigh and toe regions (Behler and King 1996). Terrestrial adults have granular skin, in contrast to aquatic adults, which have smooth mucous skin (Walters and Greenwald 1977).

    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).

    Description of Notophthalmus viridescens
    provided by BioPedia
    One of only a few species of Salamandridae that are native to North America. Larvae and adults live in small bodies of water in deciduous and coniferous forests. The larvae have laterally compressed tails, olive colored skin, and feathery gills. The larvae develop into terrestrial ‘eft’s that are up to 4.5 cms long and are reddish-orange with two rows of black-bordered red spots. The eft matures into a breeding adult after 2 or 3 years. The adult is dorsally yellowish- to greenish-brown with black-bordered red spots. Final size up to 12.4 cm. Hind legs enlarge during the breeding season as part of adaptations to amplexus. They produce up to 400 offspring, with a gestation period of up to 2 months. Carnivorous, larvae eat small invertebrates including water fleas, snails, and beetle larvae; efts eat small invertebrates, mainly those found in humus and leaf litter, including snails, spring tails, and soil mites; the adults eat mainly midge larva and other aquatic immature stages of insects. They will live up to 15 years. Predators include birds, mammals, fish, and other amphibians, however many of them are deterred by the newt's toxic skin secretions. Leech parasites also contribute to losses from the population.  Bibliography: Petranka, J. 1998. Salamanders of the United States and Canada. Washington, D.C., USA: Smithsonian Institution Press.  
    Eastern newt
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    The eastern newt (Notophthalmus viridescens) is a common newt of eastern North America. It frequents small lakes, ponds, and streams or near-by wet forests. The eastern newt produces tetrodotoxin which makes the species unpalatable to predatory fish and crayfish.[2] It has a lifespan of 12 to 15 years in the wild, and may grow to five inches in length. These animals are common aquarium pets, being either collected from the wild or sold commercially. The striking bright orange juvenile stage, which is land-dwelling, is known as a red eft. Some sources blend the general name of the species and that of the red-spotted newt subspecies into eastern red-spotted newt (although there is no "western" one).[3][4]

    Sub-species

    The eastern newt includes these four subspecies:[5]

    Notophthalmus viridescens louisianensis

    Central Newt Notophthalmus viridescens louisianensis.jpg An eft of a central newt from (*Notophthalmus viridescens louisianensis*) Iowa. Scientific classification e Kingdom: Animalia Phylum: Chordata Class: Amphibia Order: Urodela Family: Salamandridae Genus: Notophthalmus Species: N. viridescens Subspecies: N. v. louisianensis Trinomial name Notophthalmus viridescens louisianensis
    (Rafinesque, 1820)

    Central Newts (N. v. lousianensis) are a subspecies of the Eastern newt.

    Description

    2½ - 4 inches in length. Central Newts are brown or green in color, with fine black dots all over the body. There may be a row of red spots on each side of the body. The belly is yellow or orange, and is noticeably lighter than the rest of the body. The skin of newts is not as slippery as the skin of salamanders, and may appear to be rough and dry for parts of their lives.

    Life stages

    Eastern newts have three stages of life: (1) the aquatic larva or tadpole, (2) the red eft or terrestrial juvenile stage, and (3) the aquatic adult.

    Larva

    The larva possesses gills and does not leave the pond environment where it was hatched. Larvae are brown-green in color, and shed their gills when they transform into the red eft.

    Red eft

    The red eft (juvenile) stage is a bright orangish-red in color, with darker red spots outlined in black. An eastern newt can have as many as 21 of these spots. The pattern of these spots differs among the subspecies. An eastern newt's time to get from larva to eft is unknown. During this stage, the eft may travel far, acting as a dispersal stage from one pond to another, ensuring outcrossing in the population. The striking coloration of this stage is an example of aposematism — or "warning coloration" — which is a type of antipredator adaptation in which a "warning signal" is associated with the unprofitability of a prey item (i.e., its toxicity) to potential predators.[6]

    Adult

    After two or three years, the eft finds a pond and transforms into the aquatic adult. The adult's skin is a dull olive green dorsally, with a dull yellow belly, but retains the eft's characteristic black-rimmed red spots. It develops a larger, blade-like tail and characteristically slimy skin.

    It is common for the peninsula newt (N. v. piaropicola) to be neotenic, with a larva transforming directly into a sexually mature aquatic adult, never losing its external gills. The red eft stage is in these cases skipped.

    Homing

    Eastern newts home using magnetic orientation. Their magnetoreception system seems to be a hybrid of polarity-based inclination and a sun-dependent compass. Shoreward-bound eastern newts will orient themselves quite differently under light with wavelengths around 400 nm than light with wavelengths around 600 nm, while homing newts will orient themselves the same way under both short and long wavelengths.[3] Ferromagnetic material, probably biogenic magnetite, is likely present in the eastern newt's body.[4]

    Habitat and diet

    Eastern newts are at home in both coniferous and deciduous forests. They need a moist environment with either a temporary or permanent body of water, and thrive best in a muddy environment. During the eft stage, they may travel far from their original location. Red efts may often be seen in a forest after a rainstorm. Adults prefer a muddy aquatic habitat, but will move to land during a dry spell. Eastern newts have some amount of toxins in their skin, which is brightly colored to act as a warning. Even then, only 2% of larvae make it to the eft stage. Some larvae have been found in the pitchers of the carnivorous plant Sarracenia purpurea.[7]

    Eastern newts eat a variety of prey, such as insects, small mollusks and crustaceans, young amphibians, worms, and frog eggs.

    Conservation Concerns

    Although eastern newts are widespread throughout North America, they, like many other species of amphibians are increasingly threatened by several factors including, habitat fragmentation, climate change, invasive species, over exploitation, and emergent infectious diseases.[8] Wild Eastern Newts are known hosts of Batrachochytrium dendrobatidis and Ranavirus. They are also highly susceptible to the newly emergent chytrid fungus Batrachochytrium salamandrivorans[9]

    Gallery

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      Terrestrial juvenile stage ("red eft")

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      Aquatic larval stage

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      Eft near Northfield, Massachusetts

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      Eft navigating over leaves near Thomasville, Alabama

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      Eft on North Fork Mountain in eastern West Virginia

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      Eft seen along a trail in Harriman Park, New York

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      Swollen cloaca and large hind legs in a reproductive adult male

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      Adult female central newt

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      A red-spotted newt among the autumn leaves not far from Bolton,_Vermont

    References

    Citations

    1. ^ IUCN SSC Amphibian Specialist Group (2015). "Notophthalmus viridescens". IUCN Red List of Threatened Species. 2015: e.T59453A78906143. doi:10.2305/IUCN.UK.2015-4.RLTS.T59453A78906143.en. Retrieved 2 June 2018.CS1 maint: Uses authors parameter (link) .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    2. ^ Marion, Zachary H; Hay, Mark E (2011). "Chemical Defense of the Eastern Newt (Notophthalmus viridescens): Variation in Efficiency against Different Consumers and in Different Habitats". PLoS ONE. 6 (12): e27581. doi:10.1371/journal.pone.0027581. PMC 3229496. PMID 22164212.
    3. ^ a b Phillips, J; Borland, S (1994). "Use of a Specialized Magnetoreception System for Homing by the Eastern Red-Spotted Newt Notophthalmus Viridescens". The Journal of Experimental Biology. 188 (1): 275–91. PMID 9317797.
    4. ^ a b Brassart, J; Kirschvink, J. L; Phillips, J. B; Borland, S. C (1999). "Ferromagnetic material in the eastern red-spotted newt notophthalmus viridescens". The Journal of Experimental Biology. 202 Pt 22: 3155–60. PMID 10539964.
    5. ^ Behler, John L.; King, F. Wayne (1979). The Audubon Society Field Guide to North American Reptiles and Amphibians (Chanticleer Press ed.). New York: Knopf. p. 276. ISBN 978-0-394-50824-5. Retrieved 4 September 2012.
    6. ^ Santos, J. C; Coloma, L. A; Cannatella, D. C (2003). "Multiple, recurring origins of aposematism and diet specialization in poison frogs". Proceedings of the National Academy of Sciences. 100 (22): 12792–7. doi:10.1073/pnas.2133521100. JSTOR 3148039. PMC 240697. PMID 14555763.
    7. ^ Butler, Jessica L; Atwater, Daniel Z; Ellison, Aaron M (2005). "Red-spotted Newts: An Unusual Nutrient Source for Northern Pitcher Plants". Northeastern Naturalist. 12 (1): 1–10. doi:10.1656/1092-6194(2005)012[0001:rnauns]2.0.co;2. JSTOR 3858498.
    8. ^ Collins, James P; Storfer, Andrew (2003). "Global amphibian declines: Sorting the hypotheses". Diversity and Distributions. 9 (2): 89–98. doi:10.1046/j.1472-4642.2003.00012.x. JSTOR 3246802.
    9. ^ Martel, A; Blooi, M; Adriaensen, C; Van Rooij, P; Beukema, W; Fisher, M. C; Farrer, R. A; Schmidt, B. R; Tobler, U; Goka, K; Lips, K. R; Muletz, C; Zamudio, K. R; Bosch, J; Lotters, S; Wombwell, E; Garner, T. W. J; Cunningham, A. A; Spitzen-Van Der Sluijs, A; Salvidio, S; Ducatelle, R; Nishikawa, K; Nguyen, T. T; Kolby, J. E; Van Bocxlaer, I; Bossuyt, F; Pasmans, F (2014). "Recent introduction of a chytrid fungus endangers Western Palearctic salamanders". Science. 346 (6209): 630–1. doi:10.1126/science.1258268. PMC 5769814. PMID 25359973.

    Further reading

    Lifespan, longevity, and ageing
    provided by AnAge articles
    Maximum longevity: 25 years (captivity) Observations: As in other similar species, these newts feature extensive regeneration capabilities (McGann et al. 2001). They can live up to 15 years in the wild (http://amphibiaweb.org/). One specimen kept as a pet was still alive when over 25 years of age (website feedback), which is a plausible anecdote. A female reportedly lived for 15 years in captivity (http://www.pwrc.usgs.gov/neparc/). In some populations, sexual maturity can be reached in 1 year, but it usually takes at least 3 years. Some data suggests males may reach sexual maturity slightly sooner than females (http://amphibiaweb.org/).

Distribution

    Distribution and Habitat
    provided by AmphibiaWeb text

    This species is one of the most widely distributed salamanders in North America, occurring primarily from Nova Scotia to Florida, and also southwest to Ontario. It prefers ponds and lakes with dense, submerged vegetation and relatively undisturbed stretches of streams, swamps, neighboring woodlands and ditches (Behler and King 1996).

    Distribution
    provided by Animal Diversity Web

    The eastern newt, Notophthalmus viridescens, is one of only a few species in the Family Salamandridae native to North America. This newt ranges throughout most of eastern North America, from the Canadian Maritime Provinces west to the Great Lakes and south to Texas, Alabama, Georgia, and Florida (Dunn and Hagen 1999; Petranka 1998; Richmond 1997). There are four recognized subspecies: the red-spotted newt (N. v. viridescens) of the eastern and northeastern U.S. and Canada, the central newt (N. v. louisianensis) of the central states and the deep south, the broken-striped newt (N. v. dorsalis) of the Carolina coastal plains, and the peninsula newt (N. v. piaropicola) of peninsular Florida.

    Biogeographic Regions: nearctic (Native )

Morphology

    Morphology
    provided by Animal Diversity Web

    The aquatic larvae have laterally compressed tails, olive colored skin, and feathery gills. The hatchlings range in length from 7 to 9mm and have fairly smooth skin with little toxicity. Although the length of the larval period and the size at metamorphosis varies, they usually transform into a terrestrial "eft" stage after 2 to 5 months. The eft is reddish-orange in color with two rows of black-bordered red spots. It has well-developed lungs, limbs, and eyelids. The eft's skin is dry and somewhat rough and its color is a sign of its toxicity to predators. The eft has a long-slender body with a laterally flattened tail and ranges in length from 3.4 to 4.5 cm. The eft usually transforms into the mature, breeding stage after 2 to 3 years on land. The adult newt varies in color depending on its age and sex, ranging from yellowish-brown to greenish-brown dorsally and have black-bordered red spots. Its ventral color is yellow and black spots speckle the belly. The newt is slightly moist (just enough to keep its skin from drying out), with rough-scaleless skin and indistinct coastal grooves. Its size ranges in length from 7 to 12.4 cm and it has small eyes with a horizontal pupil. During the breeding season, males can be easily identified by their enlarged hind legs, with black-horny structures on the inner surfaces of their thighs and toe tips (used for gripping females during mating), swollen vents, and broadly keeled (high-wavy crest) tails.

    Range length: 7 to 12.4 cm.

    Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; poisonous

    Sexual Dimorphism: ornamentation

Habitat

    Habitat
    provided by Animal Diversity Web

    Notophthalmus viridescens inhabits both deciduous and coniferous forests. Immature larvae and the adult newts live in small bodies of freshwater (ponds, small lakes, ditches, and marshes) usually with mud bottoms. Adults can survive on land if their aquatic habitat becomes unsuitable; adults may move onto land during dry periods when the water is low or to rid themselves of ectoparasites. The juvenile "eft" stage lives in lakeshore and woodland habitats and is often seen in forest litter on rainy nights.

    Habitat Regions: temperate ; terrestrial ; freshwater

    Terrestrial Biomes: forest

    Aquatic Biomes: lakes and ponds

    Wetlands: marsh

Trophic Strategy

    Trophic Strategy
    provided by Animal Diversity Web

    The aquatic larvae eat small invertebrates including water fleas, snails, and beetle larvae; the terrestrial efts eat small invertebrates, mainly those found in humus and leaf litter, including snails, spring tails, and soil mites; the adult newts eat mainly midge larva and other aquatic immature stages of insects. Adults don't have a specialized diet, eating any small invertebrate that they can find.

    Animal Foods: insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans; zooplankton

    Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)

Associations

    Associations
    provided by Animal Diversity Web

    Eastern newts are important predators of small invertebrates in the freshwater ecosystems of eastern North America.

    Leeches appear to be a major source of adult mortality. Adults will generally flee the water and begin biting or scratching themselves in an attempt to rid their bodies of these ectoparasites, however they're not always successful.

    Commensal/Parasitic Species:

    • leeches (Hirudinea)
    Associations
    provided by Animal Diversity Web

    Predators of N. viridescens include birds, mammals, fish, and other amphibians, however many of them are deterred by the newt's toxic skin secretions.

    Known Predators:

    • birds (Aves)
    • carnivorous mammals (Mammalia)
    • fish (Actinopterygii)
    • amphibians (Amphibia)

    Anti-predator Adaptations: aposematic ; cryptic

Behavior

    Behavior
    provided by Animal Diversity Web

    Carnivorous throughout their lives, eastern newts use both chemical and visual cues to locate food. Adults seem to rely more on visual cues when feeding. They don't have a specialized diet, but temperature and water clarity, as well as prey density, can effect the feeding process.

    Communication Channels: visual ; tactile ; chemical

    Perception Channels: visual ; tactile ; chemical

Life Cycle

    Life Cycle
    provided by Animal Diversity Web

    The incubation of the eggs is somewhat dependent on temperature, but generally lasts from 3 to 8 weeks. In early fall, 3 to 4 months later, the aquatic larvae lose their gills, acquire sac-like lungs (heart transforms from two chambered heart to three, capable of supporting lungs), and emerge onto land as an eft. Two to 3 years later, the eft develops a powerful, flattened tail and returns to the water to breed, as an adult, and remains there the rest of its life, if water is permanent. (Lacking permanent water, adult newts will estivate and overwinter on land and enter vernal ponds in spring to breed.) Some eastern newt populations skip the eft stage and immediately transform into breeding adults. There are some coastal populations of eastern newts that become reproductively mature while retaining a gilled "larval" form (i.e., are neotenic). In other populations, newts enter the eft stage but never undergo a complete second metamorphosis, and enter the water only to breed. Both of these latter two cases may be in response to harsher than average environmental conditions.

    Development - Life Cycle: neotenic/paedomorphic; metamorphosis

Life Expectancy

    Life Expectancy
    provided by Animal Diversity Web

    Eastern newts have a lifespan of up to 12 to 15 years. However, mortality is high in eggs and larvae.

    Range lifespan
    Status: captivity:
    15 (high) years.

    Average lifespan
    Status: captivity:
    15.0 years.

Reproduction

    Reproduction
    provided by Animal Diversity Web

    The breeding season begins in late winter and lasts until early spring; at this time, the female is heavy with eggs and actively seeking a male. The courtship involves a unique form of amplexus. Females are attracted by the male's spots and he lures them to him by making fanning motions with his tail and wiggling, causing an enticing odor (a pheromone) to be released. The male positions himself above and forward of the female, gripping her sides just behind her forelegs with his hindlimbs and rubbing her snout with the side of his head. Males will deposit a sperm packet on the bottom of the pond and the female will proceed to pick it up with her cloaca, later using the sperm to fertilize her eggs. Males are often in competition with each other, but rival males who try to break up a pair already involved in amplexus are rarely successful. Sometimes the rival male may drop his sperm packet anyway and the female may pick up the packet when courtship with the other male is over. Male to male courtship is also common. Males tend to eat the sperm packets that are dropped in this case.

    Mating System: polygynandrous (promiscuous)

    Oviposition can take several weeks, because the female will only lay a few, widely scattered eggs, each day. It's still uncertain whether or not females will lay all of their eggs in a breeding season, however they do lay between 200 and 400 single, jelly-covered eggs on submerged vegetation, each season. As soon as the process is finished, the female newt swims away leaving her eggs to survive on their own. Both males and females reach sexual maturity around the age of 3.

    Breeding interval: Eastern newts breed once per year.

    Breeding season: The breeding season varies with latitude, beginning in late winter and lasting until early spring.

    Range number of offspring: 200 to 400.

    Range time to hatching: 3 to 8 weeks.

    Average age at sexual or reproductive maturity (female): 3 years.

    Average age at sexual or reproductive maturity (male): 3 years.

    Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous

    Average age at sexual or reproductive maturity (male)
    Sex: male:
    2000 days.

    Average age at sexual or reproductive maturity (female)
    Sex: female:
    2000 days.

    Females do not provide parental care after they deposit their eggs. Males do not invest in young past sperm production and mating.

    Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female)

Conservation Status

    Conservation Status
    provided by Animal Diversity Web

    There is no special status listed for Notophthalmus viridescens. Newts have declined in the face of habitat degradation by humans, but remain locally common in parts of their range. Adult newts will readily colonize man-made bodies of water, even in the presence of predatory fish, as their toxic skin secretions may reduce fish predation. Researchers do believe, however, that eastern newts may be suffering at higher than normal rates from diseases caused by viruses, bacteria, and fungi, due to a variety of environmental problems including pollution. Acid precipitation and deforestation may be other cause of depleted populations.

    US Federal List: no special status

    CITES: no special status

    State of Michigan List: no special status

    IUCN Red List of Threatened Species: least concern

Trends

    Life History, Abundance, Activity, and Special Behaviors
    provided by AmphibiaWeb text

    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).

Threats

    Life History, Abundance, Activity, and Special Behaviors
    provided by AmphibiaWeb text

    Raffel et al. (2010) found that eastern newts in 12 of 16 central Pennsylvania ponds were widely infected with the amphibian chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd), although they appeared healthy and did not show any overt signs of chytridiomycosis. N. viridescens may thus act as a reservoir species for Bd (Raffel et al. 2010). In the southeastern United States, Bd-infected N. viridescens have been found in Georgia, North Carolina, and Virginia, but sampling was negative in Louisiana and Tennessee (Rothermel et al. 2008). Eight dead Bd-infected newts were found in Virginia, although these individuals were apparently not part of a mass mortality event and newt populations did not decline between 2006 and 2008 (Rothermel et al. 2008). Padgett-Flohr et al. (2007) also reported Bd infections in commercially purchased N. viridescens, but did not note where infected individuals originated.

    Recently a new species of mesomycetozoan parasite (Amphibiocystidium viridescens) was reported to be widespread (Pennsylvania, West Virginia, and Massachusetts) and to have caused mortality in eastern newt populations. Infection presents as subcutaneous cysts, visible as raised bumps under the skin and in the liver. This may be another recently emerged pathogen, like the chytrid fungal pathogen Bd. Peaks in infection prevalence were found to occur in winter and early spring (Raffel et al. 2008).

    N. viridescens may be a carrier of iridoviruses. Duffus et al. (2008) examined FV3 prevalence in pond-dwelling amphibian communities of southeastern Ontario, Canada. Of five N. viridescens individuals sampled from a single pond, one was infected with frog virus 3 (FV3) but did not show clinical signs of infection, in contrast to syntopic wood frogs.

    Pollutants can affect this species. Relyea and Jones (2009) found that the glyphosate-based herbicide Roundup (in the Original Max formulation, which contains the surfactant polyethoxylated tallowamine, or POEA) was moderately toxic to larval N. viridescens, similar to the toxicity for larval ambystomatid salamanders and less than the toxicity for larval anurans. In another study, adult N. viridescens exposed to sediments with low amounts of coal-tar sealant (which can originate from asphalt parking lots), as well as to UV light, showed sublethal effects including decreased righting ability and decreased swimming speed. Although these effects did not directly result in mortality, they could potentially influence survival by decreasing the ability to catch prey or evade predators (Bommarito 2009). Likewise, exposure to the insecticide endosulfan has been shown to reduce mating success in N. viridescens by inhibiting release or potency of female pheromones and by delaying male responses to female odors (Park et al. 2001; Park and Propper 2002).

Benefits

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    This species does not have any significant negative economic importance.

    Negative Impacts: injures humans (poisonous )

    Benefits
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    The eastern newt may benefit humans by helping to control the populations of aquatic insects, including mosquitoes. They are aesthetically interesting and may play an important ecological role in freshwater and woodland habitats. Eastern Newts are sometimes kept as aquarium or terrarium pets and have even been commercially collected for the pet trade. Effects of this trade on exploited populations is not well documented.

    Positive Impacts: pet trade

Other Articles

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    N. viridescens appears to be involved in a Mullerian mimicry complex, with several other salamander species possibly mimicking the red eft, with its toxic skin secretions.

    This newt is capable of locating its home pond through true navigation using its olfaction and light-dependent magnetic compass.