Eastern Newt
Encyclopedia
The Eastern Newt or Red-spotted Newt (Notophthalmus viridescens) is a common salamander
of eastern North America
. Eastern newts dwell in wet forest
s with small lakes or ponds. They can coexist in an aquatic environment with fish
, however, their skin secretes a poisonous substance when the newt is threatened or injured. They have a lifespan of 12 to 15 years in the wild, and may grow to 5 inches in length. The newts are a common aquarium
pet
, being either collected from the wild or purchased. The strikingly colored (orange) juvenile stage, which is land-dwelling, is known as the "red eft".
Eastern Newts have three stages of life: the aquatic larva
or tadpole
, the red eft or terrestrial juvenile stage, and the aquatic adult. The larva possesses gill
s 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 terrestrial red eft. The red eft is 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. During this stage, the eft may travel far, acting as a dispersal stage from one pond to another, ensuring outcrossing
in the population. After two or three years, the eft finds a pond and transforms into the aquatic adult. The adult's skin is olive green, but retains the eft's characteristic outlined red spots. It has a larger and wider tail
and characteristically slimy skin.
The Peninsula Newt (N. v. piaropicola) typically skips the red eft stage and metamorphoses directly into an aquatic adult. It is also common for this subspecies to be neotenic
, with a larva transforming directly into a sexually-mature adult while retaining its external gills.
using magnetic orientation. Their magnetoreception system seems to be a hybrid of polarity-based inclination and a sun-dependant compass. Shoreward-bound Eastern Newts will orient themselves quite differently under light with wavelength
s of ~400 nm than light with wavelengths of ~600 nm, while homing newts will orient themselves the same way under both short and long wavelengths. It is considered very likely that ferromagnetic material, probably biogenic magnetite
, is present in the Eastern Newt's body.
and deciduous forest
s. 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
.
Eastern newts eat a variety of foods such as insect
s, small mollusks and crustacean
s, young amphibian
s, and frog
eggs
. They also eat worms.
partially filled with dechlorinated water and equipped with an air-operated filter. While oxygenation isn't necessary for the newts to breathe, it allows the bacteria that decomposes their waste to flourish. This prevents dangerous buildups of ammonia and other anaerobically produced chemicals. The aquarium should be topped with a screen lid to prevent the newts from escaping and to provide proper ventilation. The newts will require an area to haul out of the water from time to time; this can be provided with a piece of driftwood
, a "turtle dock" sold by pet stores, an "island" (a patch of soil or gravel with sphagnum moss and liverwort), or with terra cotta
pots filled with aquarium gravel. If desired, pothos
, java fern, java moss
, or other semi-aquatic plants can be placed in the pot to help absorb nitrogenous waste produced by the newts. Hiding places for the newts should be provided in the form of aquarium plants and/or clay pots on the bottom of the aquarium. Water temperatures in the aquarium should stay between 60 °F (15.6 °C) and 70 °F (21.1 °C) during the simulated summer. Should you choose to simulate a winter to induce breeding or simply to recreate wild conditions more accurately, water temperature should approach but not drop below 40 °F (4.4 °C). 10-20% of the water in the newt aquarium should be replaced every week. The newts should be fed bloodworms, earthworm
s, redworms, daphnia
, mosquito
larva (collected from non-polluted sources), brine shrimp
and commercial amphibian diets such as Reptomin (although some may refuse these prepared foods). Feeding some type of live food is necessary, even if the newt happily accepts dry or prepared foods. Any uneaten food should be netted out to avoid fouling the water.
Salamander
Salamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...
of eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Eastern newts dwell in wet forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s with small lakes or ponds. They can coexist in an aquatic environment with fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, however, their skin secretes a poisonous substance when the newt is threatened or injured. They have a lifespan of 12 to 15 years in the wild, and may grow to 5 inches in length. The newts are a common aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
pet
Pet
A pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...
, being either collected from the wild or purchased. The strikingly colored (orange) juvenile stage, which is land-dwelling, is known as the "red eft".
Life stages
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
or tadpole
Tadpole
A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
, the red eft or terrestrial juvenile stage, and the aquatic adult. The larva possesses gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s 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 terrestrial red eft. The red eft is bright orangish
Orange (colour)
The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The...
-red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
in color, with darker red spots outlined in black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
. An Eastern Newt can have as many as 21 of these spots. The pattern of these spots differs among the subspecies. During this stage, the eft may travel far, acting as a dispersal stage from one pond to another, ensuring outcrossing
Outcrossing
Outcrossing is the practice of introducing unrelated genetic material into a breeding line. It increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities...
in the population. After two or three years, the eft finds a pond and transforms into the aquatic adult. The adult's skin is olive green, but retains the eft's characteristic outlined red spots. It has a larger and wider tail
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
and characteristically slimy skin.
The Peninsula Newt (N. v. piaropicola) typically skips the red eft stage and metamorphoses directly into an aquatic adult. It is also common for this subspecies to be neotenic
Neoteny
Neoteny , also called juvenilization , is one of the two ways by which paedomorphism can arise. Paedomorphism is the retention by adults of traits previously seen only in juveniles, and is a subject studied in the field of developmental biology. In neoteny, the physiological development of an...
, with a larva transforming directly into a sexually-mature adult while retaining its external gills.
Homing
Eastern Newts homeHoming (biology)
Homing is the inherent ability of an animal to navigate towards an original location through unfamiliar areas. This location may be either a home territory, or a breeding spot.-Uses:...
using magnetic orientation. Their magnetoreception system seems to be a hybrid of polarity-based inclination and a sun-dependant compass. Shoreward-bound Eastern Newts will orient themselves quite differently under light with wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
s of ~400 nm than light with wavelengths of ~600 nm, while homing newts will orient themselves the same way under both short and long wavelengths. It is considered very likely that ferromagnetic material, probably biogenic magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
, is present in the Eastern Newt's body.
Habitat and diet
Eastern Newts are at home in both coniferousPinophyta
The conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority being...
and deciduous forest
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
s. 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
Sarracenia purpurea
Sarracenia purpurea, commonly known as the purple pitcher plant, northern pitcher plant, or side-saddle flower, is a carnivorous plant in the family Sarraceniaceae...
.
Eastern newts eat a variety of foods such as insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, small mollusks and crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, young amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, and frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. They also eat worms.
Captive care
A small group (1–3) of adult Eastern Newts can be maintained in a 10-gallon aquariumAquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
partially filled with dechlorinated water and equipped with an air-operated filter. While oxygenation isn't necessary for the newts to breathe, it allows the bacteria that decomposes their waste to flourish. This prevents dangerous buildups of ammonia and other anaerobically produced chemicals. The aquarium should be topped with a screen lid to prevent the newts from escaping and to provide proper ventilation. The newts will require an area to haul out of the water from time to time; this can be provided with a piece of driftwood
Driftwood
Driftwood is wood that has been washed onto a shore or beach of a sea or river by the action of winds, tides, waves or man. It is a form of marine debris or tidewrack....
, a "turtle dock" sold by pet stores, an "island" (a patch of soil or gravel with sphagnum moss and liverwort), or with terra cotta
Terra cotta
Terracotta, Terra cotta or Terra-cotta is a clay-based unglazed ceramic, although the term can also be applied to glazed ceramics where the fired body is porous and red in color...
pots filled with aquarium gravel. If desired, pothos
Epipremnum aureum
Epipremnum aureum, also known as the Pothos , Money Plant, Silver Vine, Centipede tongavine, Devil's Ivy and Solomon Islands' Ivy, is an aroid native to southeastern Asia and New Guinea...
, java fern, java moss
Java moss
Java Moss is a moss belonging to the Hypnaceae family. Native to Southeast Asia, it is commonly used in freshwater aquariums. It attaches to rocks, roots, and driftwood...
, or other semi-aquatic plants can be placed in the pot to help absorb nitrogenous waste produced by the newts. Hiding places for the newts should be provided in the form of aquarium plants and/or clay pots on the bottom of the aquarium. Water temperatures in the aquarium should stay between 60 °F (15.6 °C) and 70 °F (21.1 °C) during the simulated summer. Should you choose to simulate a winter to induce breeding or simply to recreate wild conditions more accurately, water temperature should approach but not drop below 40 °F (4.4 °C). 10-20% of the water in the newt aquarium should be replaced every week. The newts should be fed bloodworms, earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s, redworms, daphnia
Daphnia
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style...
, mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
larva (collected from non-polluted sources), brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
and commercial amphibian diets such as Reptomin (although some may refuse these prepared foods). Feeding some type of live food is necessary, even if the newt happily accepts dry or prepared foods. Any uneaten food should be netted out to avoid fouling the water.