Introduction
Eastern newts are rather small, sometimes brilliantly colored newts. The bodies of adult N. viridescens viridescens are a light brown to tan color with red colored spots on both sides of the slight dorsal ridge, running from the back of the head to the start of the tail. These bright spots indicate the toxicity of N. viridescens to potential predators. Some subspecies have a broken line or continuous line, instead of red dots, while others lack aposematic coloration on the dorsum altogether. The abdomen is yellow to orange, and covered in tiny black dots, as is the rest of the body in many individuals. Males and females of most populations are roughly the same size. Outside of the breeding season, males can be distinguished from females by their more robust hind limbs, and the presence of yellowish glandular spot on rear area of the vent. During breeding season semi-aquatic, adult males display black nuptial pads, cornified toe tips, swollen cloaca, and laterally compressed tails. The skin of semi-aquatic adults is rather smooth, compared to efts. 

Eft coloration varies among the four subspecies, and ranges from vivid red-orange, to rusty brown, with some nearly identical in color as the adults. As red efts near sexual maturity, the bright juvenile color fades, and is replaced by the subtle hues of the adults. Efts may be up to 10 times more toxic than adults, as their bright coloration indicates. This anti-predator feature is utilized by some sympatric species, including Pseudotriton ruber and Psedutriton montanus, two palatable species who are thought to be Batesian mimics of Notophthalmus viridescens efts. Certain populations or subspecies may skip the terrestrial eft stage, and spend the juvenile period in the water. Such individuals may go through complete metamorphosis into adults, however, some may develop into neotenes. Aquatic juveniles are similar in coloration as the adults, with smoother, olive colored skin, and laterally compressed tails. This is common in areas where the surrounding terrestrial habitat lacks adequate cover for the efts. The terrestrial eft stage may last 2-7 years, depending on the subspecies and population. When an eft reaches sexual maturity it returns to the water, whereupon the new adult remains semi-aquatic for the remainder of its life. More accurately, they will remain semi-aquatic in the right conditions. During the change from terrestrial eft to aquatic adult, the newts physiology changes drastically, almost as if it were going through a second, less severe metamorphosis. The skin becomes porous and thinner so as to absorb more oxygen under water, the hind legs become reduced, and the eye sight is modified for keener vision in murky waters. 

Adults are typically semi-aquatic, or mostly aquatic, however, individuals and populations may return to a terrestrial mode of life under certain circumstances, such as diminishing water sources, polluted water sources, high temperatures, and to kill aquatic parasites. Adults can re-develop terrestrial adaptations, including thicker skin, stronger limbs to support the body, rounded tail, and modified eye sight; physical changes that are sometimes regarded as metamorphoses. Some populations may also leave the water to seek out a hiding spot for hibernation during the winter season. As long as they remain adequately moist, adult N. viridescens spp. can live on land very long periods of time, if not indefinitely. In a sense, N. viridescens spp. are capable of toggling their physiology between that suited for a terrestrial life and that of a semi-aquatic, as seen fit.

Neotenic adults are greenish-olive colored as well, and may or may not retain the dark stripe through eyes, characteristic of larvae. Males also develop swollen cloaca, nuptial pads, and cornified toe tips. Neoteny in N. viridescens is through to be induced by environmental conditions, i.e. unsuitable terrestrial habitat in some cases. Experiments have shown that neoteny occurs more frequently in low density larvae populations, where larvae can grow rapidly.

Breeding behavior is nearly identical in each subspecies, and has been well documented. During the breeding season, males develop laterally compressed tail fins, swollen cloaca, cornified toe tips, and nuptial pads on the insides of the back legs. The nuptial pads are adaptation to aid the male in holding the female during amplexus. Males also possess hedonic pits at the back of the head, which are absent or reduced in females. Males and females are generally the same size.

N. viridescens breeds from fall through summer, depending on the subspecies and climate. Southern populations generally breed in late fall and early winter, through spring. Breeding in March and April has been documented in Louisiana populations (N.v. louisianensis). Intermediate latitude populations generally breed in the spring, and northern populations breed in fall and spring.

Males outnumber females at breeding sites, and actively compete for females. Males typically compete more aggressively for larger females, as they are typically carrying more eggs. In the majority of cases, females are unresponsive to approaching males, prompting the male to quickly amplex her, which prevents her from darting away. Amplexus consists of the male grasping the female just in front of the fore limbs, with his hind limbs. The rough nuptial pads on the inner legs of breeding males prevent females from wriggling free. Occasionally, males may accidentally amplex other males, which are usually released after assuming a bowed head position. During amplexus, which could last for several hours, the male will rub the females snout with his forelimbs, chin, and the sides of his head, where genial glands are found, and fan cloacal secretions toward her snout with his tail. Responsive females often raise their tails at a 90° angle during amplexus. Several minutes before the female is released, the male increases courtship behavior with aggressive body contortions, and increased tail fanning. After releasing the female, the male will move in front of her, while undulating the body, and raising his tail. If interested, the female will follow the male, periodically pressing her head against his tail or cloacal region. This behavior prompts the male to release one or more spermatophores. After deposition, the male will turn perpendicular to the female to block her path. At this point, the female moves slightly forward to align her cloaca with the sperm cap for collection.

The fore described behavior is the ideal case, however, many times the female simply darts away after she is released from the males grip. Another factor disrupting breeding is competition from other males. Once in amplexus, competing males attempt to dislodge male and female pairs, however they are usually unsuccessful. Competing males may assume the behavior of breeding females during the spermatophore deposition stage, allowing the rival male to move in between the courting pair and deposit his own spermatophores. In some instances where a male amplexes another male, the amplexed male may not assume the bowed head position described earlier. Instead, he may act as a female by nudging the amplexing males tail after being released, prompting him to release a spermatophore. In such instances, the spurious male may consume the spermatophore.

Occasionally, a simpler courtship routine is enacted. If a female is responsive to an approaching male, he may simply perform an undulating dance, followed by the deposition of a spermatophore. This behavior has been observed in captivity, and in few cases.

Eggs are attached singly to aquatic plants, and sometimes with the plant tip folded over the egg. Females may deposit eggs a few at a time for several months. Incubation is typically complete within 20-35 days, depending on temperature.

New larvae are pond-type, with longer, bushy gills, and higher tail fins. Hatchlings are greenish-brown to yellowish, with two brown or black stripes running dorsolaterally down the sides of the back. Advanced larvae are light brown to yellowish, with black lines running from the snout, through the eyes. The red dorsal patterns may develop in the late larval stage in those subspecies that possess red dorsal markings as adults. Larvae are carnivorous, and cannibalistic. Larvae have been noted to separate into groups within a pond according to size, presumably a mechanism to avoid predation by larger larvae. The larval stage lasts anywhere from 2-5 months, depending on the subspecies and location. 

Upon metamorphosis, efts retreat to terrestrial hiding spots in droves. Eft coloration is apparent within 2.5 weeks of metamorphosis in terrestrial juveniles.

Semi-aquatic adults are found in slow moving, permanent water bodies, including ponds, lakes, swamps, ditches, and slow sections of streams. Aquatic habitats with abundant plant life also harbor abundant newt populations. Newts can be found in abundance around the shoreline, however, some may venture to deeper waters. Those populations that leave the water for winter hibernation or summer aestivation typically return to the same breeding ponds every year. Experiments have shown that N. viridescens possess homing capabilities when displaced from their ponds. N. v. dorsalis and N. v. louisianensis have been noted to remain hidden in muddy bottoms of evaporating ponds, rather than leave and seek out terrestrial hiding spots.

Subspecies

Notophthalmus viridescens viridescens (Rafinesque, 1820) Red Spotted Newt, Eastern Newt
This is the largest subspecies, reaching lengths 4.41inches (11.2 cm) total length. Adults of the nominate form are tannish-olive colored dorsally, with a lighter colored, yellowish belly. Three to eight orange-red spots outlined in black run dorsolaterally from the back of the head and/or top of head, to the start of the tail. These spots will vary in size and formation within a given group, but are a distinguishing characteristic of this subspecies. The entire body is usually covered in tiny black dots, including the tail, head, legs, belly, and dorsum. Efts of the nominate form are bright red or orange, and possess the typical reddish spots outlined in black that mark the adults. Efts of this subspecies are often called red efts, a reflection of their stunning red-orange coloration. 

N.v. viridescens have the widest distribution, which includes nearly the entire eastern coast of the United States, excluding Florida and southern Georgia, and upwards into southern Quebec and Ontario, Canada. N.v. viridescens can be found westward to central Alabama, Tennessee, Kentucky, Indiana, Quebec and Ontario, Canada. 

Notophthalmus viridescens dorsalis (Harlan, 1828) Broken Stripe Newt

N. v. dorsalis have the smallest distribution, which includes northeastern South Carolina, and southeastern to mid-eastern North Carolina. In the Carolina's, N. v. dorsalis are noted for breeding and residing in clay-based bays and limesink depressions, surrounded by long leaf pine and wiregrass, pine plantations, and hardwood forests. 

Notophthalmus viridescens louisianensis (Wolterstorff, 1914) Central Newt
This subspecies possesses larger black spots about the body, legs, and tail, in addition to fine dots. Some individuals may possess faint red spots along the back, discontinuously outlined in black. Efts of this subspecies are not as brightly colored as the nominate from, sometimes appearing dark brownish-red in coloration. The eft stage is sometimes completely skipped in this subspecies, especially in areas with minimal cover in the surrounding terrestrial environment. Adults may stay active year round in some populations, with mating occurring in the fall, winter, and spring, while others may seek hibernation on land during the colder months. Metamorphosed individuals may remain semi-aquatic, bypassing the eft stage, while others will develop into terrestrial efts.

N. v. louisianensis cover a relatively large area, which spans the intersection of northern Florida, Georgia, and Mississippi, westward to eastern Texas, and north into lower Ontario, Canada, passing through eastern Oklahoma, central and eastern Missouri, eastern Iowa, Wisconsin, and eastern Minnesota. The easternmost distribution borders the range of N. v. viridescens in most areas. Large gaps in distribution occur in central Illinois, Indiana, western-central Wisconsin, and southwestern Louisiana. Aquatic habitat includes shallow ponds, slow moving permanent water bodies, and calm streams. 

Notophthalmus viridescens piaropicola (Rafinesque, 1820) Peninsula Newt
This subspecies possesses fine speckling of black dots all over the body, tail, and legs. The background coloration is usually dark tan, sometimes black, and the belly is lighter colored. N. v. piaropicola lack red spotting altogether. Transformed efts lack the bright coloration of the nominate form, and are often similar in coloration as the adults, sometimes darker. The eft stage is sometimes completely skipped in this subspecies, especially in areas with minimal cover in the surrounding terrestrial environment. 

N. v. piaropicola have a comparatively small distribution, with includes only the peninsula of Florida. Aquatic habitat includes slow moving water bodies, often those with significant colonies of hyacinth. Aquatic newts can be found residing among the maze of hyacinth roots, and efts commonly reside in semi-tropical surrounding forests. This subspecies has been documented in several nature reserves and parks in Florida, including the Florida Everglades National Park, the Archbold Biological Station, the Corkscrew Swamp Sanctuary, and Big Cypress National Preserve Park.

Etymology & Synonomy

Taxonomic Synonymy: Salamandra stellio (Say, 1819), Triturus viridescens (Rafinesque, 1820), Triturus miniatus (Rafinesque, 1820), Salamandra symmetrca (Harlan, 1825), Salamandra punctatissima (Wood, 1825), Salamandra dorsalis (Harlan, 1829), Salamandra greeni (Gray, 1831), Salamandra symmetrica (Harlan, 1835), Salamandra millepunctata (Storer, 1840), Salamandra coccinea (DeKay, 1842), Triton dorsalis (Holbrook, 1842), Triton symetricus (Holbrook, 1842), Notophthalmus viridescens (Baird, 1850), Tristella symetrica (Gray, 1850), Molge ocellata (Gray, 1850), Notophthalmus miniatus (Gray, 1850), Notophthalmus viridescens (Gray, 1850), Triton punctatissimus (Dumeril, Bibron, and Dumeril, 1854), Triton symetricus (Dumeril, Bibron, and Dumeril, 1854), Diemyctylus viridescens (Hallowell, 1856), Notophthalma viridescens (Gray, 1858), Triton viridescens (Strauch, 1870), Salamandra ventralis (Provancher, 1875), Triturus viridescens (Boulenger, 1878), Molge viridescens (Boulenger, 1882), Diemyctylus miniatus miniatus (Yarrow, 1882), Diemyctylus miniatus viridescens (Yarrow, 1882), Diemyctylus viridescens viridescens (Cope, 1889), Diemyctylus minutus (Gage & Norris, 1890), Diemyctylus viridescens var. vittatus (Garman, 1896), Notophthalmus viridescens (Gill, 1907), Diemictylus viridescens (Gill, 1907), Diemyctylus viridescens louisianensis (Wolterstorff, 1914), Notophthalmus viridescens viridescens (Stejneger & Barbour, 1917), Notophthalmus viridescens vittatus (Stejneger & Barbour, 1917), Triturus dorsalis (Dunn, 1918), Triturus viridescens (Dunn, 1918), Triturus viridescens symmetrica (Schmidt, 1924), Diemictylus viridescens louisianensis (Wolterstorff, 1925), Diemictylus viridescens dorsalis (Wolterstorff, 1925), Triturus viridescens lousianae (Strecker, 1928), Triturus viridescens louisianensis (Schmidt & Necker, 1935), Notophthalmus viridescens louisianensis (Herre, 1936), Diemictylus viridescens forma columbia (Scharlinski, 1939), Triturus louisianensis (Carr, 1940), Triturus viridescens viridescens (Bishop, 1943), Triturus viridescens piaropicola (Schwartz & Duellman, 1952), Diemictylus viridescens evergladensis (Peterson, 1952), Notophthalmus viridescens (Smith, 1953), Diemictylus viridescens (Schmidt, 1953), Notophthalmus viridescens dorsalis (Smith, 1953), Diemictylus viridescens dorsalis (Schmidt, 1953), Notophthalmus viridescens louisianensis (Smith, 1953), Diemictylus viridescens louisianensis (Schmidt, 1953), Notophthalmus viridescens piaropicola (Smith, 1953), Notophthalmus viridescens (Mecham, 1967), Notophthalmus viridescens louisianensis (Mecham, 1967).

Captive Environment

Adult N. viridescens should be housed in a semi-aquatic tank with more water than land. Most adult individuals will remain largely aquatic year round in ideal habitats, only leaving the water for short periods of time. However, some adult individuals have been noted to remain terrestrial for long periods of time, and may require a larger land area with hiding places. Although short and moderately long bouts of terrestrial behavior are normal for this species, a sudden change from semi-aquatic to terrestrial may indicate a problem with the water quality. It is recommended to keep a freshwater test kit on hand, and regularly check the pH, ammonia, nitrite, and nitrate levels (for more information about water chemistry see article 0006 - Water Quality and Amphibians and article 0009 - Introduction to the Nitrogen Cycle ). Adult N. viridescens prefer cooler, fish-less, slow-moving or still water bodies, which should reflect the way their home is constructed. The water area can support a filter with a carbon and sponge insert, or a canister type biological filters for larger tanks. The filter should not create a strong current or disturbance, otherwise the newts may not enter the water at all. Most filters can be positioned so that the output is facing the side of the tank, or small rocks or thick vegetation can block and slow the output if it cannot be re-positioned. If a filter is not included, a partial water change (10%-20%) should be done weekly or biweekly. Gravel is the standard form of submersed substrate, but bare bottom tanks are acceptable as well. With bare bottom tanks, decaying organic matter (i.e. feces, shed skin, uneaten food, etc.) should be siphoned out weekly or biweekly, and adequate biological filtration should be provided. Live aquatic plants should be included as N. viridescens prefer densely planted water bodies. Elodea, Crinum, Lilaeopsis, and Vesicularia are commonly used, and are acceptable for breeding purposes. N. v. piaropicola are often found in beds of hyacinth, which would make a natural addition to the captive home of this subspecies. If lighting is included, only fluorescent bulbs should be used, as they do not radiate heat in the manner an incandescent bulb does. As with all amphibians, to avoid the spread of foreign pathogens, N. viridescens should not be housed with any other amphibian species.

Adult N. viridescens are typically housed in a large aquarium with 8-30 inches of water, and a land area composed of large, mossy rocks or driftwood breaking the surface of the water. Larger tanks can be sectioned off at the 1/3 mark with plexi-glass, making two separate areas in the tank. The larger side is for the water area, and the smaller side is for a woodland/shoreline type habitat. The substrate of the woodland side should be biologically active, and composed of a nutrient-rich mixture (see article 0021 - Substrate Mixtures for the Vivarium for more information about substrate mixtures). This type of setup may be beneficial to those individuals that spend a considerable amount of time on land, terrestrial adults, juveniles who have yet to make the transition to semi-aquatic adult, and for individuals that will hibernate during the winter. Alternatively, potted plants can be submerged in the water to serve as land islands. 

Notophthalmus viridescens spp. juveniles are true efts, spending the first few years of life completely terrestrial. N. v. viridescens efts are perhaps the most recognized eft-stage species because of their striking coloration during this phase. Other subspecies, such as N. v. dorsalis may not posses this striking coloration during the eft stage, and instead may resemble the adult color scheme. Notophthalmus efts are physiologically suited for a terrestrial life upon metamorphosis, with thicker skin, modified eyesight, stronger legs to support the body, and a high concentration of Tetrodotoxin (see article 0011 - Toxicity and Defense Methods of Amphibians for information on toxicity, and article 0021 - Substrate Mixtures for the Vivarium for more information about substrate mixtures). 

Metamorphosed efts should be kept terrestrially for the first few years of life, prior to reaching sexual maturity and assuming a semi-aquatic lifestyle. New efts measure around 25-35mm, and can usually be kept in a woodland type, terrestrial setup. A basic setup would consist of 3-6 inches of moist earth, live plants, and a few dark hiding places (rock caves, small terra cotta planters, etc.). See article 0021 - Substrate Mixtures for the Vivarium for more information about substrate mixtures.

If a suitable source of natural substrate cannot be obtained, small efts can be kept on bleach-free paper toweling until they are large enough to handle the soil substrate. Bleach-free paper towel substrate must be replaced often (every few days or so) to ensure the health of the inhabitants. Food items quickly rot and become toxic on paper toweling because it is a sterile environment, lacking the microbes found in natural soil to help break down organic matter. Because paper towels provide such a sterile environment, they also allow any harmful pathogens found on the newts to multiply at an exponential rate, like in a petri dish, which is another reason the substrate must be replaced often. It is also necessary to ensure the paper towels are always adequately moist, but not soaking wet, as paper towels are capable of absorbing moisture from the inhabitants as they begin to dry out, which could lead to the desiccation of the newts.

Some keepers prefer the natural setup method, while other prefer the sterile, clinical method of paper toweling substrate. Either can be used to rear efts to adulthood, and preference for either is really at the discretion of the keeper.

A more natural setup would consist of a large woodland area with an ample supply of densely-planted water designed in such a way that terrestrial adolescents can make the transition to sexually mature adult in the same environment, and reside in that same environment indefinitely. However, this is not practical in most situations, and newly mature adults are usually relocated into a more aquatic setup when sexual maturity is reached. More elaborate setups can include several different species of plant life, mosses, caves, burrows, sloping hill sides, rocks, driftwood, small logs, natural-looking water bodies, waterfalls, etc. See article 0020 - Captive Habitats: Ideas, Instructions, and Examples, See article 0021 - Substrate Mixtures for the Vivarium, and the Captive & Wild Habitats section of the Photo Gallery.

As with all amphibians, tap water should be treated with a water conditioner or primer prior to the introduction of amphibians. Never used plain tap water, de-ionized, distilled, or reverse osmosis water with amphibians. Also, the tank should be cycled (nitrogen cycle) prior to the introduction of amphibians. See article 0006 - Water Quality and Amphibians and article 0009 - Introduction to the Nitrogen Cycle for more information about water quality and the importance of the nitrogen cycle.

Feeding

Amphibians should be given a variety of different live foods to ensure proper nourishment and health. Chopped earthworm, tubifex worms, blood worms, and maggots will work as semi-staple foods for semi-aquatic adults if the others are unattainable. Keep in mind that maggots are not easily digested by many caudate species, especially the smaller ones. If undigested maggots are found in the tank, then they should not be offered. See article 0002 - Amphibian Foods and Feeding Tips for more information on commonly available food items.

Gabor, C., and C. Nice. 2004. Genetic variation among populations of Eastern Newts, Notophthalmus viridescens. Herpetologica 60(3): 373-386.

Literature References

Behler, John L.,  and F. Wayne King. National Audubon Society Field Guide to North American Reptiles and Amphibians.
   New York: Knopf, 1979, 1996.

Petranka, James W. Salamanders of the United States and Canada.
   Smithsonian Institution Press, 1998.