Salamanders In North America
Most of the 112 species of North America salamanders occur in the Appalachian region. In terms of species richness of salamanders, no other part of the earth compares with Appalachia. However, salamanders also occur over most of the rest of North America, in moist habitats ranging from boreal to subtropical.
The mudpuppies and waterdogs are five species of aquatic, neotenous salamanders in the family Necturidae, occurring in eastern North America. The most widespread and abundant species is the mudpuppy (Necturus maculosus).
The hellbender (Cryptobranchus alleganiensis) is the only North American representative of the Cryptobranchidae, the family of giant salamanders. The hellbender is an impressively large animal, which can reach a body length of 2.5 ft (74 cm). Hellbenders live in streams and rivers. The hellbender is one of the relatively few salamanders that does not have internal fertilization of its eggs. The male hellbender deposits sperm over the ova after they are laid, so that external fertilization takes place.
Amphiumas (family Amphiumidae) are long, eellike, aquatic creatures with tiny legs, that live in streams, swamps, and other wet places in the extreme southeastern United States. Amphiumas are vicious animals when disturbed, and can inflict a painful bite. The most widespread of the three North American species is the twotoed amphiuma (Amphiuma means) of Florida and parts of coastal Georgia and the Carolinas. The three-toed amphiuma (Amphiuma tridactylum) can achieve a body length of about 3 ft (1 m), and is the longest amphibian in North America.
Sirens (family Sirenidae) are also long and slender, aquatic salamanders. Sirens have diminutive forelimbs, and they lack hind limbs. These animals are aquatic, and they retain gills and other larval characters as adults. Mating of sirens has not been observed, but it is believed that they have external fertilization. There are three species of sirens in North America, the most widespread of which is the lesser siren (Siren intermedia), occurring in the drainage of the Mississippi River and in the southeastern states. The greater siren (S. lacertina) of the southeastern coastal plain can be as long as 3 ft (95 cm).
The mole salamanders (family Ambystomidae) are terrestrial as adults, commonly burrowing into moist ground or rotting wood. The largest of the 17 North American species is the tiger salamander (Ambystoma tigrinum), measuring up to 12 in (30 cm) in length. This is a widespread species, occurring over most of the United States, parts of southern Canada, and into northern Mexico. The Pacific giant salamander (Dicamptodon ensatus) of the temperate rainforests of the west coast is another large species, with a length of up to 12 in (30 cm). Other relatively widespread mole salamanders are the spotted salamander (A. maculatum) of the eastern United States and southeastern Canada, the marbled salamander (A. opacum) of the southeastern states, and the blue-spotted salamander (A. laterale) of northeastern North America.
There are at least 77 species of lungless salamanders (family Plethodontidae) in North America. The redbacked salamander (Plethodon cinereus) is a common and widespread species in the northeastern United States and southeastern Canada. The ensatina salamander (Ensatina eschscholtzi) occurs in subalpine conifer forests of the humid west coast.
There are six species of newts (family Salamandridae) in North America. The eastern newt (Notophthalmus viridescens) is widespread in the east. Initially transformed adults usually leave their natal pond to wander in moist forests for several years as the red-eft stage. The eft eventually returns to an aquatic habitat where it transforms into a sexually mature adult, and it spends the rest of its life in this stage. Some races of eastern newts do not have the red eft stage. The most widespread of the western newts is the rough-skinned newt (Taricha granulosa), occurring in or near various types of still-water aquatic habitats of the humid west coast.
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