Mole salamander

Mole salamanders are a special group of animals known as Ambystoma. They live only in North America and are part of the advanced salamanders family. One of the most famous mole salamanders is the axolotl, which scientists study to learn about how some animals can keep their baby features their whole lives. Another well-known mole salamander is the tiger salamander, which is often kept as a pet and is the official amphibian in four US states. These interesting creatures help us learn more about nature and animal life.

General description

Terrestrial mole salamanders have wide, protruding eyes, noticeable grooves along their sides, and thick arms. They often display bright patterns like blue spots or yellow bars on dark skin. These salamanders mostly live underground in burrows, either ones they dig themselves or ones left by other animals. Some northern types may stay in these burrows all winter. They live alone and eat insects and other small creatures. Adults rarely come out of the water except to return to their birth ponds to lay eggs.

All mole salamanders lay large eggs in water. Their babies, called larvae, live completely in water and have gills to breathe. These larvae have long fins and grow limbs with four toes on their front legs and five toes on their back legs. Their eyes are wide apart and don’t have eyelids. Some larvae can become the size of adults before they change into their adult form, a process called metamorphosis. During this change, they lose their gills and fins, grow thicker skin and limbs, develop eyelids, and get lungs to live on land. One famous type of mole salamander is the axolotl, which keeps its larval features into adulthood because it cannot make a certain substance needed to change fully into an adult.

Tiger salamander complex

Tiger salamanders (Ambystoma tigrinum complex) have big heads, small eyes, and thick bodies. They are some of the largest mole salamanders and have relatively big larvae.

These salamanders live in many different places across North America. Because of this wide range, different groups of tiger salamanders look and act in various ways. Scientists are still studying whether these groups are separate species or subspecies and what causes them to change over time. Some groups that used to be considered part of Ambystoma tigrinum are now recognized as their own species. For example:

1. Ambystoma mavortium (barred tiger salamander) includes former subspecies like A. t. diaboli, A. t. mavortium, A. t. melanostictum, A. t. nebulosum, and A. t. stebbinsi.
2. Ambystoma californiense (California tiger salamander)
3. Ambystoma velasci (Plateau tiger salamander), which lives in the same areas as the axolotl (A. mexicanum)

Hybrid all-female populations

Some mole salamanders are special because they are all-female groups found in the Great Lakes region and northeastern North America. These females need sperm from related species to start their eggs developing, but the eggs usually grow without using the sperm’s genes. Sometimes, they add the sperm’s genes to their own babies.

These all-female salamanders can have genes from up to five different species, such as the blue-spotted salamander, Jefferson salamander, small-mouthed salamander, streamside salamander, and tiger salamander. This mixing creates many different types of these salamanders. Even though their bodies look similar to other salamanders, their genetic makeup is very unique. Scientists believe these all-female salamanders are one of the oldest known groups of animals that only have females.

Limb regeneration

The Ambystoma mexicanum, a type of salamander known for keeping its baby-like features, is very good at growing back lost body parts. Scientists study these salamanders to learn how limbs can regrow. When a limb is lost, special cells called blastema form and help grow a new limb. These cells need to fix their DNA to work properly, which is an important part of how regeneration happens.

Taxonomy

The group of animals called mole salamanders belongs to a family named Ambystomatidae. Scientists once thought one group of these salamanders, called Rhyacosiredon, was its own special family. But later studies showed that Rhyacosiredon is very close to some Ambystoma species. This means Ambystoma includes animals that are not all directly related to each other.

The name Ambystoma was created in 1839 by a scientist named Johann Jakob von Tschudi. Some people think he may have meant to write Amblystoma, which means "blunt-mouth." But because we do not know for sure, the name Ambystoma is the one we use today.

Species

The genus Ambystoma includes 32 different types of salamanders, with the newest one being A. bishopi. Some of these salamanders live mostly on land, while others keep their gills and stay in water their whole lives. There are even some groups that have both kinds living together.

There are also two special groups of salamanders that can only have babies with others of the same group. These are called the Silvery salamander (A. platineum) and Tremblay's salamander (A. tremblayi).

Image	Species and author	Common name	Distribution	Lifestyle	IUCN status
	A. altamirani Dugès, 1895	Mountain stream salamander, Achoque	Central Mexico, west and south of the Valley of Mexico	Terrestrial and neotenic
	A. amblycephalum Taylor, 1940	Blunt-headed salamander	West-central Mexico (Michoacán state), near Morelia	Terrestrial and neotenic
	A. andersoni (Brandon and Krebs, 1984)	Anderson's salamander	West-central Mexico (Michoacán state), Laguna de Zacapu	Neotenic
	A. annulatum Cope, 1886	Ringed salamander	South-central United States (Arkansas, Illinois, Missouri, Oklahoma), Ozark Plateau and Ouachita Mountains	Terrestrial
	A. barbouri Kraus & Petranka, 1989	Streamside salamander	South-midwest United States (Indiana, Kentucky, Ohio, Tennessee, West Virginia)	Terrestrial
	A. bishopi Pauly, Piskurek & Shaffer, 2007	Reticulated flatwoods salamander	Southeast United States (Florida Panhandle and southernmost Georgia), west of the Apalachicola-Flint River	Terrestrial
	A. bombypellum (Taylor, 1940)	Delicate-skinned salamander	Central Mexico (State of Mexico) near Jilotepec	Terrestrial
	A. californiense Gray, 1853	California tiger salamander	Central Valley of California	Terrestrial
	A. cingulatum Cope, 1868	Frosted flatwoods salamander	Southeast United States (southern South Carolina and Georgia south to northern Florida)	Terrestrial
	A. dumerilii (Dugès, 1870)	Lake Pátzcuaro salamander, Achoque	West-central Mexico (Michoacán state), Lake Pátzcuaro	Neotenic
	A. flavipiperatum Dixon, 1963	Yellow-peppered salamander, Ajolote de Chapala	West-central Mexico (Jalisco)	Terrestrial
	A. gracile (Baird, 1859)	Northwestern salamander	Northwest North America (southernmost Alaska to northern California)	Terrestrial
	A. granulosum Taylor, 1944	Granular salamander, Ajolote	Central Mexico (State of Mexico) near Toluca	Terrestrial
	A. jeffersonianum (Green, 1827)	Jefferson salamander	Northeastern North America (Ontario south to Virginia and west to Illinois)	Terrestrial
	A. laterale Hallowell, 1856	Blue-spotted salamander	Northeastern North America (Nova Scotia west to Manitoba and Minnesota and south to Indiana and New Jersey)	Terrestrial
	A. leorae Taylor, 1943	Leora's stream salamander, Ajolote	Central Mexico (Mexico state - Puebla border), Mount Tlaloc	Terrestrial
	A. lermaense (Taylor, 1940)	Lake Lerma salamander	Central Mexico (State of Mexico), Lake Lerma near Toluca	Terrestrial and neotenic
	A. mabeei Bishop, 1928	Mabee's salamander	Coastal southeast United States (southeast Virginia to South Carolina)	Terrestrial
	A. macrodactylum Baird, 1950	Long-toed salamander	Northwest North America (Alaska south to northern California and east to Alberta and Montana)	Terrestrial
	A. maculatum (Shaw, 1802)	Spotted salamander	Eastern North America (Nova Scotia west to Wisconsin and south to eastern Texas and Georgia)	Terrestrial
	A. mavortium Baird, 1850	Barred tiger salamander	Western North America (Manitoba south to Texas and west to Washington and California)	Terrestrial and neotenic
	A. mexicanum (Shaw and Nodder, 1798)	Axolotl	Central Mexico (State of Mexico), Lake Xochimilco	Neotenic
	A. opacum (Gravenhorst, 1807)	Marbled salamander	Eastern United States (New Hampshire south to northern Florida and east to Missouri and Texas)	Terrestrial
	A. ordinarium Taylor, 1940	Puerto Hondo stream salamander	West-central Mexico (Michoacán state), Puerto Hondo stream	Terrestrial and neotenic
	A. rivulare Taylor, 1940	Michoacan stream salamander	Central Mexico (western State of Mexico)	Terrestrial and neotenic
	A. rosaceum Taylor, 1941	Tarahumara salamander	Northwest Mexico, Sierra Madre Occidental	Terrestrial and neotenic
	A. silvense Webb, 2004	Durango salamander	Northwest Mexico (Durango and Chihuahua), Sierra Madre Occidental	Terrestrial and neotenic
	A. talpoideum Holbrook, 1838	Mole salamander	Southeast United States (Virginia west to Oklahoma and south to northern Florida)	Terrestrial and neotenic
	A. taylori Brandon, Maruska, and Rumph, 1982	Taylor's salamander	Southeast Mexico (Puebla), Laguna Alchichica	Neotenic
	A. texanum Matthes, 1855	Small-mouth salamander	South-central United States (Ohio west to Nebraska and south to Texas and Alabama)	Terrestrial
	A. tigrinum (Green, 1825)	Eastern tiger salamander	Eastern North America (New York northwest to Manitoba and south to Texas and northern Florida)	Terrestrial and neotenic
	A. velasci (Dugès, 1888)	Plateau tiger salamander	Mexican Plateau	Terrestrial and neotenic