''Ambystoma talpoideum'', the mole salamander, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
found in much of the eastern and central
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, from
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
to
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
, north to
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
, east to
Kentucky
Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to ...
, with isolated populations in
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
and
Indiana
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...
. Older sources often refer to this species as the tadpole salamander because some individuals remain in a
neotenic
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared ...
state. This salamander lives among the leaf litter on the forest floor, migrating to ponds to breed.
Description
Mole salamanders are stocky, with short bodies and large heads. They can grow to 10 cm (4 in) in length. They are normally gray or dark brown in color, with darker mottling and lighter gray undersides. Males can be distinguished by the presence of a swollen cloaca. Larvae and paedomorphic adults are aquatic and have large feathery gills. ''A. talpoideum'' can be distinguished from other salamander larvae by the presence of two light stripes on their underside
Distribution and habitat
Mole salamanders are found in south eastern lowland areas of the Gulf Coastal Plains of the United States. Their main range extends from eastern Texas to southern South Carolina and inland as far as southern Illinois. It is absent from southern Florida and Louisiana, and there are separate populations in Kentucky, Virginia, Tennessee, North Carolina, northern South Carolina, northern Georgia and northern Alabama. There is also a small isolated population within the southernmost tip of Indiana. They inhabit floodplain pine or broadleaf forests, especially near gum and cypress ponds. Adults live under the surface of leaf litter while larvae are aquatic and found in ponds and ephemeral, fish-free waters.
Behavior
Primarily
nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
, the mole salamander is found in habitats of moist forest debris, usually near a permanent source of water. The adult range is up to about and the animals migrate to near bodies of water on rainy nights in winter when the breeding season approaches. The
eggs
Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...
are laid in the spring, during heavy rains. Some larvae undergo
metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
while others are
neotenic
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared ...
and retain their gills. In larger bodies of water where
predatory
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
fish like the
bluegill
The bluegill (''Lepomis macrochirus''), sometimes referred to as "bream", "brim", "sunny", or "copper nose" as is common in Texas, is a species of North American freshwater fish, native to and commonly found in streams, rivers, lakes, ponds and ...
(''Lepomis macrochirus'') are present, metamorphosis is more common. When attacked, adults and juveniles lower their heads to expose their
parotoid gland
The parotoid gland (alternatively, paratoid gland) is an external skin gland on the back, neck, and shoulder of toads and some frogs and salamanders. It can secrete a number of milky alkaloid substances (depending on the species) known collective ...
s which exude a noxious secretion.
[ This salamander is an opportunistic feeder, eating almost anything smaller than itself which it can overpower, including various ]arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s and tadpoles.[ It has been revealed that A. talpoideum's diet consists almost completely of various arthropods and only a small number of other Ambystomatidae larvae.]
Conservation
In its Red List of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...
, the IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
lists ''Ambystoma talpoideum'' as being "Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
" because the population trend is stable. Threats to this species include destruction of forest ponds and swamp habitat, the filling in or deepening of breeding ponds, and the introduction of predatory fish. In Indiana
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...
, the mole salamander is listed as an endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
.
References
Amphibian Species of the World: ''Ambystoma talpoideum''
{{Taxonbar, from=Q2161721
Mole salamanders
Amphibians described in 1838