Newts and European Salamanders: Salamandridae
NEWTS AND EUROPEAN SALAMANDERS: SalamandridaeSMOOTH NEWT (Triturus vulgaris): SPECIES ACCOUNTS
GREAT CRESTED NEWT (Triturus cristatus): SPECIES ACCOUNTS
EUROPEAN FIRE SALAMANDER (Salamandra salamandra): SPECIES ACCOUNTS
MANDARIN SALAMANDER (Tylototriton verrucosus): SPECIES ACCOUNTS
JAPANESE FIRE-BELLIED NEWT (Cynops pyrrhogaster): SPECIES ACCOUNTS
GOLDEN-STRIPED SALAMANDER (Chioglossa lusitanica): SPECIES ACCOUNTS
Newts and European salamanders have long, slender bodies, long tails, sturdy legs, and poisonous skin. Some species have large skin glands that stick out from the head. Newts that have just gone through metamorphosis and begun their life on land are called efts. Metamorphosis (MEH-tuh-MORE-feh-sis) is the process by which some animals change body form before becoming adults. Newts and European salamanders are 3 to 14 inches (7 to 35 centimeters) long. They have four toes on their front legs and four or five toes on their hind legs. These salamanders do not have the grooves on the sides of their body that many other salamanders have. Efts and adults have lungs; larvae have external gills that stick up behind their heads. Larvae (LAR-vee) are animals in an early stage that change body form in metamorphosis. Gills are organs for obtaining oxygen from water. Many newts and European salamanders develop back body and tail fins when they enter the water in the breeding season.
All newts and European salamanders release substances from their skin that are poisonous or bad-tasting to predators. Many of the salamanders that make these poisons are brightly colored. The skin of most species of newts and European salamanders is rough, except during the water-dwelling phase. In the water, the skin becomes smooth, thin, and slimy. In the water, salamanders breathe through their skin, meaning they absorb oxygen directly from the water. In the water-dwelling phase, newts and European salamanders shed their skin frequently. Some newts eat the shed skin.
Because they look for food underwater, newts and European salamanders have eyes that are shaped for seeing prey, and their mouth is shaped for sucking in prey. In the water-dwelling phase, newts have organs in the skin that make up a system called the lateral (LAT-uhr-uhl) line. With these organs the newt feels tiny water currents and thus can detect moving prey, even in the dark and in muddy water.
Some keep the body form of larvae even though they become adults and can reproduce. These adults do not make the move to land and remain in water throughout life.
Newts and European salamanders live in scattered areas across the Northern Hemisphere, including western and eastern North America, Europe, Japan and other areas in Asia, and the northern part of Africa.
Newts and European salamanders live in damp places close to ponds and streams, where breeding takes place. In the landdwelling phase, newts and European salamanders need damp conditions and live in dense plant cover or in crack in rocks and under logs, where conditions stay moist at the drier times of year. Because the larvae live in water, all newts and European salamanders need water for reproduction. Many of these animals breed in ponds, but some breed in larger lakes and others in mountain streams. Many newts and European salamanders do well in ponds that dry up during the summer, because these ponds cannot support fish, dragonfly larvae, and other water-dwelling animals that prey on newt and salamander larvae.
Newts and European salamanders eat small invertebrate prey, including insects, earthworms, slugs, and snails. Invertebrates (in-VER-teh-brehts) are animals without backbones. In the water-dwelling phase, newts eat water insects and are fierce predators of frog tadpoles. The larvae of newts and European salamanders eat small invertebrates, such as water fleas.
BEHAVIOR AND REPRODUCTION
Most newts and European salamanders live on land as adults but move to water to breed. Some of these animals stay in the water for several months around breeding time, but the amount of time spent in the water varies greatly among species and even sometimes within one population of the same species. Newts that lay eggs one at a time have longer breeding seasons and, thus, spend more time in the water, because it takes many weeks for a female to lay all her eggs. Species that lay their eggs in clusters spend little time in the water.
Scientists know little about the behavior of newts and European salamanders during the land-dwelling, because these animals are rarely seen. At least some species, especially eastern newts, have highly developed sensing powers that help them to return to the same breeding ponds each spring. These newts can detect at least one thing in the environment that gives them directional information, such as a smell, the position of the Sun, the pattern of light in the sky, or the direction of the magnetic field of the Earth.
When bothered by predators, some newts raise their heads, chests, and tails to show the bright colors on their bellies. These newts often rock back and forth and release a strong-smelling poison through their skin. The poison of some newts is one of the most powerful natural toxins.
During mating, a male places a sperm bag close to a female and then pushes her over it or uses displays to lure her over it, so that she takes the sperm up into her cloaca, and it is united with eggs inside her body. The cloaca (kloh-AY-kuh) is the chamber in some animals that holds waste from the kidneys and intestines, holds eggs and sperm that are about to be released to the outside, holds sperm entering a female's body, and is the passage through which young are born. The female stores the sperm in special organs in her body until she is ready to lay her eggs. Some females lay single eggs on the leaves of water plants and then wrap the eggs in leaves to hide them from predators such as fish.
WHAT'S THE DIFFERENCE?
There is no simple way to tell newts and salamanders apart. Species that spend a long period each year living in water and becoming temporarily adapted to life in water are called newts.
Transfer of sperm in a sperm bag has two interesting consequences. First, it is unreliable: In some species, many sperm bags are missed by females. Second, rival males can interfere. For example, in several species rival males mimic female behavior, causing the original males to release sperm bags that are not picked up by females. To make sure this does not happen and to make sure their sperm gets into a female, some males defend females by picking them up and carrying them away if a rival male approaches.
Chemical communication is important in the mating of newts and European salamanders. Males have glands that release scented chemicals that make females receptive to them.
In most species of newts and European salamanders the females lay their fertilized (FUR-teh-lyzed) eggs. The eggs hatch into larvae that live in the water for a while and then go through metamorphosis to become adults. In four species of European salamanders, however, the females keep the fertilized eggs inside their bodies and give birth to large larvae or, in some instances, young salamanders that look like adults but are not ready to reproduce. In these four species only a small number of eggs complete development. In Caucasian salamanders only two fully developed young are born after three or four years inside the female. Fire salamanders, alpine salamanders, and Lanza's alpine salamanders also reproduce this way.
NEWTS, EUROPEAN SALAMANDERS, AND PEOPLE
Because they taste bad and can be poisonous, newts and European salamanders are not eaten by humans. Several species are popular as pets, but they are well known for their ability to escape from all but the most secure tank.
The World Conservation Union (IUCN) lists one species of newts and European salamanders as Extinct, one as Critically Endangered, nine as Endangered, ten as Vulnerable, and eleven as Low Risk/Near Threatened. Extinct means no longer in existence. Critically Endangered means facing extremely high risk of extinction in the wild. Endangered means facing very high risk of extinction in the wild. Vulnerable means facing high risk of extinction in the wild. Low Risk/Near Threatened means at risk of becoming threatened with extinction in the future.
Across or Down?
Even if they don't know much about amphibians, people who do a lot of crossword puzzles know the word "eft." "Young newt" is a common crossword clue.
Newts and European salamanders are threatened by loss of habitat as the result of too much cutting of trees, the spread of cities, and poor farming practices. Some of these salamanders can live together with people in areas where farmers use traditional methods, such as making natural fences out of hedges and digging ponds for livestock. Modern farming methods are dangerous to salamanders. Ponds are filled in, hedges are torn up, and chemical fertilizers as well as the chemicals used to kill insects and weeds also kill salamanders.
Physical characteristics: Smooth newts are slender and small, usually less than about 4 inches (11 centimeters) long. The tail makes up about one-half of the total length of the animal. In the landdwelling phase, smooth newts are brown or dark gray. The skin secretions of smooth newts taste bad to predators, but they are not poisonous, so they provide little protection. Smooth newts are eaten by birds and other animals.
Geographic range: Smooth newts live in Europe.
Habitat: Smooth newts live in woodlands, grasslands, clumps of trees and shrubs, rows of hedges or trees surrounding fields, and yards and gardens. These salamanders breed in small ponds.
Diet: Smooth newts eat small invertebrates and frog tadpoles.
Behavior and reproduction: Smooth newts return to ponds to breed in early spring and stay in the water for several months. During the breeding season male and female smooth newts look very different from each other. Males develop a high crest that runs along the back and tail. The crest has a jagged edge and, like the rest of the body, is marked with large, dark spots. Stripes of red and blue decorate the lower edge of the male's tail, just behind the greatly swollen, dark cloaca. The toes on the hind limbs of the male develop flaps of skin. These flaps help the male swim fast in pursuit of females.
Female smooth newts lay several hundred eggs during the breeding season. The eggs are laid one at a time, and the female carefully wraps each egg in a folded leaf. The eggs hatch into tiny meat-eating larvae, which grow and go through metamorphosis over the summer months to leave the water in late summer at a length of approximately 0.8 inches (2 centimeters). The young newts spend the next two or three years on land before they return to water to breed as mature adults.
Smooth newts and people: Smooth newts have no known importance to people.
Conservation status: Smooth newts are not considered threatened or endangered. ∎
Physical characteristics: Great crested newts get their name from the large, deeply notched crest that runs along the backs of breeding males. The males also have a tail that is thick from top to bottom and is decorated with a bold white stripe. Great crested newts can be as long as 6 inches (16 centimeters). Because of an abnormality in their chromosomes (KROH-muh-sohms), or the parts of a cell that hold the DNA, 50 percent of young great crested newts die before they hatch.
Geographic range: Great crested newts live in Europe.
Habitat: Great crested newts need dense cover during their landdwelling phase and large, deep ponds for breeding.
Diet: Great crested newts eat small invertebrates, frog tadpoles, and the larvae of other newts.
Behavior and reproduction: Great crested newts live as long as sixteen years. They spend much of their lives on land, and little is known about their habits. When these newts are handled, glands in their skin release a bitter-smelling milky substance that humans and predators, such as water birds and hedgehogs, find highly offensive. The bright orange and black on the belly of great crested newts act as warning colors. Predators associate the color with the bad taste and do not attack the newts.
Adult great crested newts travel to ponds early in the spring. In Sweden they have been observed moving over snow and entering ponds that are still partially covered with ice. Females start the breeding season full of large eggs, but it takes males several weeks to fully develop their thick tails and their back crests. Males that come out of winter hibernation with larger fat reserves develop larger crests, and it is likely they are more attractive to females than are males with small crests.
While in breeding ponds, great crested newts are secretive by day and mate at dusk. A male takes up a position in front of a female and displays to her with rhythmic beats of his tail. The movement sends a chemical released by a large gland in the male's cloaca toward the female's snout. The male also displays his large, white-striped tail, which is bright in the dim light. If the female responds to the displays by moving toward him, the male turns and deposits a sperm bag on the bottom of the pond. The female places herself over it and picks it up with her open cloaca.
Two or three days after mating, female great crested newts begin to lay eggs, which have united with sperm inside them. This process takes many weeks. Great crested newts lay seventy to six hundred eggs, usually 150–200, one at a time, carefully wrapping each egg in the leaf of a water plant. After two to three weeks, the eggs hatch into tiny larvae, which start to feed on water animals such as water fleas. Development and metamorphosis take two to three months, and the young leave the pond in late summer and autumn looking like miniature adults. They grow larger until they are old enough to reproduce. Female newts mate several times during the breeding season, interrupting egg-laying to replenish the supply of sperm.
Great crested newts and people: Great crested newts have no known importance to people.
Conservation status: Great crested newts are not considered threatened or endangered. Their numbers are decreasing, however, as a result of changes in their habitat caused by changes in land use and farming practices. In France, however, the great crested newt is slowly expanding its range. In central France, great crested newts overlap with marbled newts, and mating between the two species is common. In some parts of France, great crested newts seem to be handling new patterns of land use better than marbled newts and are expanding into ponds previously used only by marbled newts, whose numbers are decreasing as a result. ∎
Physical characteristics: European fire salamanders have a variety of colors and skin patterns. Some of these salamanders are black with yellow markings, and some are yellow with black or red or orange spots or stripes. They reach a length of 11 inches (28 centimeters) from tip of snout to tip of tail. Females are slightly larger than males. The legs are short and stout with broad toes, and the tail is tube-shaped and shorter than the body. European fire salamanders have two rows of poison glands along the sides of the body and a cluster of poison glands on each side of the head behind the eyes.
Geographic range: European fire salamanders live in Europe.
Habitat: European fire salamanders live in burrows in deciduous forests and, sometimes, in coniferous forests at heights of 656 to 3,280 feet (200 to 1,000 meters). Coniferous (koh-NIH-fuh-russ) forests are made up of trees that bear their seeds inside cones. Deciduous (dih-SIH-juh-wuhs) forests are made up of trees that lose their leaves during cold or dry seasons.
Diet: European fire salamanders eat worms, insects, insect larvae, and slugs.
Behavior and reproduction: European fire salamanders are active at night. When conditions are damp, these salamanders come out of their burrows to look for food. After metamorphosis European fire salamanders live entirely on land. They defend the ground around their burrows against intrusion by neighbors. The striking color patterns on these salamanders act as warning signs. When attacked, fire salamanders squirt toxin from their skin glands over a great distance.
During mating, which takes place on land, a male European fire salamander grasps a female from below. He stimulates the female with glands on his head, and when the female is ready he deposits a sperm bag. The male then flips his tail to one side so that the female falls onto the sperm bag. The sperm enter the female's body and unite with eggs. Larvae develop inside the eggs, and the female lays the eggs in ponds or streams in batches of twelve to fifty. In a few high-altitude populations, the larvae stay in the female throughout development and are released having the adult body form. During development in the female, larvae may eat smaller siblings. As a result, only a few salamanders in each batch of eggs complete development.
European fire salamanders and people: European fire salamanders have no known importance to people.
Conservation status: European fire salamanders are not considered threatened or endangered. ∎
Physical characteristics: Mandarin salamanders have a sturdy build. They reach a length of 7 inches (18 centimeters) from tip of snout to tip of tail. These salamanders have a large head with large ridges of skin glands. When mandarin salamanders are in the water-dwelling phase, the tail is long, is flat from side to side, and has a fin. Mandarin salamanders are black or dark brown and are covered with two rows of large brown, orange, or red bumps. These bright colors are a warning sign to predators. Mandarin salamanders release a bad-tasting substance from their skin. The skin has a grainy texture.
Geographic range: Mandarin salamanders live in China, India, Nepal, Thailand, and Vietnam.
Habitat: Mandarin salamanders live in hills and mountains. The natural habitat is damp woodland and forest, but these salamanders also live in habitats made by people, such as rice fields and tea gardens.
Diet: Mandarin salamanders eat small invertebrates.
Behavior and reproduction: Scientists know little about how mandarin salamanders behave. These salamanders live on land for most of their lives and travel to ponds and other water bodies in March or April when the monsoon rains begin. Mating occurs in water. The male clasps the female before transferring his sperm bag. Fertilization takes place inside the female's body. The female lays thirty to sixty eggs in water. Some scientists believe the females guard their eggs. Mandarin salamanders can reproduce when they are three to five years old.
Mandarin salamanders and people: Mandarin salamanders are caught and sold as pets.
Conservation status: Mandarin salamanders are not considered threatened or endangered. ∎
Physical characteristics: Japanese fire-bellied newts reach a length of 5 inches (12 centimeters) from tip of snout to tip of tail. The tail is long and has a large fin that helps the salamanders swim powerfully. The tail of males has a thin string at the tip. Japanese fire-bellied newts have a black back and a bright red, spotted belly that acts as warning. When attacked, these salamanders release poison from their skin, especially from large glands on the head.
Geographic range: Japanese fire-bellied newts live on Honshu, Shikoku, and Kyushu, Japan.
Habitat: Japanese fire-bellied newts live in ponds and pools, their numbers often becoming quite large.
Diet: Japanese fire-bellied newts eat small invertebrates.
Behavior and reproduction: Except for mating practices, scientists do not know how Japanese fire-bellied newts behave. Mating takes place in water. The males do not grasp the females' bodies but stand in front of the females, sometimes restraining them with one hind foot. In this position a male beats the tip of his tail, producing a current in the water that carries a scented chemical from glands in his swollen cloaca to the female's snout. Fertilization takes place inside the female's body. She lays the eggs in water, and the eggs attach to underwater plants.
Japanese fire-bellied newts and people: Their bright color makes Japanese fire-bellied newts very popular as pets.
Conservation status: Japanese fire-bellied newts are not considered threatened or endangered. ∎
Physical characteristics: Golden-striped salamanders reach a length of 6 inches (16 centimeters) from tip of snout to tip of tail. The body and tail are long and thin. The tail makes up about two-thirds of the total length of the animal. Golden-striped salamanders are dark brown and have two golden brown stripes on the back that join to form one stripe on the tail. On some salamanders, the stripes are broken into lines of spots. Golden-striped salamanders have a long, narrow head, large eyes, and a long, sticky tongue for catching prey.
Geographic range: Golden-striped salamanders live in Europe in northern Portugal and the northwestern part of Spain.
Habitat: Golden-striped salamanders live in wet, mountainous areas.
Diet: Golden-striped salamanders eat flies and other insects.
Behavior and reproduction: Golden-striped salamanders are active at night only when it is damp and thus only in areas where there is heavy rainfall. They are dormant underground or in caves during the winter and also are dormant during dry periods in the summer. If attacked, golden-striped salamanders can run quickly. If caught, they can break off their tails. The tail regrows but never reaches its original length. When they are attacked, golden-striped salamanders release a milky poison from their skin.
Golden-striped salamanders spend most of their lives on land but breed in water. Males develop swellings on the upper parts of their front legs during the breeding season. The females lay clumps of as many as twenty eggs in summer or autumn under rocks in springs and streams. The larvae spend the winter in the water.
Golden-striped salamanders and people: Golden-striped salamanders have no known importance to people.
Conservation status: The World Conservation Union (IUCN) lists golden-striped salamanders as Low Risk/Near Threatened because of habitat loss due to land drainage, replacement of natural forest by farms, and pollution from farming chemicals. This means they are at risk of becoming threatened with extinction in the future. ∎
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