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).

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).

The eastern newt is one of only a few species of Salamandridae native to North America. It is found throughout most of eastern North America, from Atlantic coast to the Great Lakes and south to Texas, Alabama, Georgia, and Florida.

Biogeographic Regions: nearctic (Native )

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 )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Eastern newts occur throughout the eastern United States and adjacent southern Canada; west to Minnesota, eastern Kansas, and eastern Texas (Petranka 1998).

Aquatic larvae have flattened tails, olive colored skin, and feathery gills. Hatchlings range in length from 7 to 9 mm and have smooth skin that isn't toxic. Eastern newts usually transform into a terrestrial "eft" stage after 2 to 5 months as an aquatic larva. 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 signal to predators that it is toxic. The eft has a long-slender body with a flattened tail and ranges in length from 3.4 to 4.5 cm. The eft usually grows enough to breed after 2 to 3 years on land. These adult newts are yellowish-brown to greenish-brown and have black-bordered red spots. The belly color is yellow with black spots. The adult newt is slightly moist (just enough to keep its skin from drying out), with rough skin. Its size ranges from 7 to 12.4 cm long and it has small eyes with a horizontal pupil.

Range length: 7 to 12.4 cm.

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

Sexual Dimorphism: ornamentation

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

Length: 14 cm

Eastern newts inhabit both deciduous and coniferous forests. Immature larvae and 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 watery habitat dries up; adults may move onto land when the water is low. 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

• Terrestrial
• Freshwater

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

Comments: Adults and larvae inhabit lakes, ponds, swamps, and quiet stream pools, especially those lacking predaceous fishes. Efts and sometimes adults (for example, overwintering ones) inhabit wooded areas (terrestrial eft stage lasts 2-7 years). In some areas, such as the northeastern United States, adults may be permanently aquatic, but in other areas they may leave the water in summer or fall.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

In some localities, adults migrate annually between terrestrial nonbreeding habitats and breeding ponds. The timing of migrations varies throughout the range, depending on local conditions. Overland movements often are most intense during rainy weather. Mass migrations were observed in February in West Virginia (Green and Pauley 1987); the bulk of migration occurred in late March-late April and late summer in Virginia. Adults tend to be philopatric to their native ponds and site tenacious within ponds (J. Herpetol. 27:149).

The aquatic larvae eat small invertebrates including Cladocera, Gastropoda, and Coleoptera. Efts eat small invertebrates, mainly those found in leaf litter, including Gastropoda, Collembola, and soil Acari. Adult newts eat mainly Chironomidae and other aquatic immature stages of insects.

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

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)

Comments: Adults and larvae feed opportunistically on small aquatic animals, including amphibian eggs. Terrestrial efts eat small invertebrates; specialize on snails in some areas.

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

Hirudinea and other parasites attack eastern newts, which sometimes leave the water and begin to bite at and scratch parasites to get them off.

Commensal/Parasitic Species:

• leeches (Hirudinea)

Predators of eastern newts include Aves, carnivorous Mammalia, Actinopterygii, and other Amphibia, but 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

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)

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

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: Represented by many and/or large occurrences throughout most of the range.

>1,000,000 individuals

Comments: Total adult population size is unknown but likely exceeds 1,000,000.

Efts moved over an area averaging 270 square meters in Massachusetts. Apparently moves randomly in shallows of ponds. Larval abundance peaked at over 20/sq m in late spring in a North Carolina pond (Harris et al. 1988).

Eastern newts produce highly toxic skin secretions. The red eft stage is particularly toxic. Unlike most salamanders, efts commonly walk in the open during daytime; if attacked, they curl the body and display their bright colors. Although efts and adults are sometimes eaten by bullfrogs, garter snakes, turtles, and some other animals, many predators find them unpalatable and quickly learn to avoid them.

Eastern newts use both chemical and visual cues to locate food. Adults seem to rely more on visual cues when feeding. Eastern newts also use chemical cues, visual cues, and touch to communicate when breeding.

Communication Channels: visual ; tactile ; chemical

Perception Channels: visual ; tactile ; chemical

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

Comments: Terrestrial stage hibernates in winter, especially in north. Aquatic stages may be active all year, even under ice; may ingest and slowly digest food in winter (Jiang and Claussen, 1993, J. Herpetol. 27:414-419). Migrations correspond with nights of heavy rainfall.

Eggs develop for 3 to 8 weeks, depending on water temperature. In early fall, 3 to 4 months later, the aquatic larvae lose their gills, develop sac-like 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. Adults remain in their pond or lake for the rest of their life, if the water is permanent, or spend dry seasons on land and move back to the water in the spring (the wet season). Some eastern newt populations skip the eft stage and immediately transform into breeding adults. There are some coastal populations of eastern newts that can breed while still in their gilled, larval form or the eft form.

Development - Life Cycle: neotenic/paedomorphic; metamorphosis

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

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.

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.

The breeding season begins in late winter and lasts until early spring. Females are attracted by a male's spots, which he uses to lure a female towards him. He also makes fanning motions with his tail and emits a pheromone (sexual odor). When a female approaches, the male climbs onto her back and begins to rub his head on her snout. Males then deposit a sperm packet on the bottom of the pond and the female moves forward to pick it up. Males might compete with each other, but it is usually females who choose their mates.

Mating System: polygynandrous (promiscuous)

It can take several weeks after breeding for females to lay their eggs. They lay a few eggs each day in different places. Females lay between 200 and 400 single, jelly-covered eggs on submerged plants 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.

Eastern newts do not provide care for their young after the eggs are laid.

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

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)

The timing of migrations and breeding vary throughout the range, depending on local conditions. In the water, males find females engage in courtship (may occur in spring or in both spring and fall). Courtship may or may not involve grasping and holding the female. Breeding males eventually deposit spermatophores on the pond bottom. Females pick up sperm from one or more spermatophores and later deposit up to a few hundred eggs, which are attached singly to submerged vegetation, generally in late winter or early spring, sometimes in summer or fall. Larvae hatch usually within about 2-5 weeks and metamorphose to the aquatic subadult or terrestrial eft stage about 2-3 months later, generally in late summer or early fall in most areas. Efts live on land for up to several years before returning to water and beginning to breed. In some areas, the terrestrial eft stage is omitted. Breeding by gilled, mature adults occurs in some areas.

There is no special status listed for eastern newts. Populations have declined as a result of habitat degradation, but they are still common in many parts of their range. Adult newts will inhabit man-made bodies of water, including those with fish, as their toxic skin may help to reduce their risk of being eaten by fish.

IUCN Red List of Threatened Species: least concern

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

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

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Large range in eastern North America and adjacent southern Canada; abundant; many secure populations.

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Broad. Generalist or community with all key requirements common.

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).

Global Short Term Trend: Relatively stable to increase of 25%

Comments: Could be increasing with increasing beaver populations (Petranka 1998).

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: May have increased as creation of farm ponds augmented available habitat (Petranka 1998).

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).

Comments: Roads negatively impact salamander abundance in roadside habitat and may serve as partial barriers to movement (deMaynadier and Hunter 2000). Introduced bluegill sunfish may cause declines in larval abundance (Smith et al. 1999). However, the species is unthreatened overall.

See Attum et al. (2002) for information on how collection for human use affects newt size and mass in harvested populations.

There are no negative affects of eastern newts on humans. Their skin is toxic, so they should never be eaten or handled with broken skin, but they are not very toxic to humans.

Negative Impacts: injures humans (poisonous )

Eastern newts may benefit humans by helping to control populations of aquatic insects, including Culicidae. They 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.

Positive Impacts: pet trade

This species does not have any significant negative economic importance.

Negative Impacts: injures humans (poisonous )

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

Comments: Gabor and Nice (2004) analyzed 18 allozyme loci to examine the evolutionary relationships among the four subspecies of eastern newts: viridescens, dorsalis, louisianensis, and piaropicola. "Despite moderate amounts of genetic variation, phylogenetic and phenetic analyses of the relationships among 12 sites resulted in trees that were inconsistent with the current subspecific classification. Cluster and phylogenetic analyses of allele frequency variation confirmed this, indicating an absence of significant differentiation among subspecies. Instead, populations appear to cluster into groups representing geographic units that do not directly correspond to the currently recognized subspecies. The morphological and life history differences among the subspecies are not clearly associated with differentiation at allozyme loci. Recent divergence, gene flow, or phenotypic plasticity may explain the lack of correlation between genetic and morphological differentiation."

See Reilly (1990) for information on phylogenetic relationships of the 3 species of Notophthalmus.