Amphiuma
Encyclopedia
Amphiuma is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of aquatic salamander
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...

s, the only extant genus within the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Amphiumidae (icon). They are also known to fishermen as "conger eels" or "congo snakes", which are zoologically
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...

 incorrect designations. Amphiumas have one of the largest amounts of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 in the living world, around 25 times more than a human.

Description

Amphiumas have an elongated body, generally grey
Grey
Grey or gray is an achromatic or neutral color.Complementary colors are defined to mix to grey, either additively or subtractively, and many color models place complements opposite each other in a color wheel. To produce grey in RGB displays, the R, G, and B primary light sources are combined 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...

 in color. They do have legs, but they are very small; while amphiumas can be up to 116 cm (45.7 in) long, their legs measure only up to about 2 cm (0.78740157480315 in). Therefore, they can resemble eel
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...

s. They also lack eyelids or a tongue.

Female amphiumas lay their 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...

 in wet mud, and then remain coiled around them for about five months, until they hatch. The larvae have external gills, but after about four months these external gills disappear and the lungs begin to work. One pair of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...

s, with fully functioning internal gills, is retained and never disappears, so the metamorphosis remains incomplete.

Distribution

Amphiumas inhabit the southeastern part of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. They share much of the same distribution with the sirens
Siren (amphibian)
Sirenidae, the sirens, is a family of aquatic salamanders. Family members have very small forelimbs, and lack hind limbs altogether. In one species, the skeleton in their forelimbs is made of only cartilage. In contrast to most other salamanders, they have external gills bunched together on the...

, although they are not closely related.

In the past amphiumas have been further distributed. Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s from the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 epoch show that they once were distributed in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 as well.

Behavior

During the day amphiumas hide in vegetation, and at night they become active and go hunting. Their prey include 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...

s, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

s, 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...

, 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, 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 and even other amphiumas. Hunting and eating habits have been observed to be very similar to that of the Axolotl, including the sucking in of food into their stomachs with vacuum force. If provoked they can become aggressive. They can be found in most wetlands in the coastal plain of the southeastern U.S., even ones which periodically dry, as they are able to aestivate in the moist mud below drained marshland and other ephemeral
Ephemeral
Ephemeral things are transitory, existing only briefly. Typically the term is used to describe objects found in nature, although it can describe a wide range of things....

 wetlands. Amphiuma are rarely encountered on land, but it is possible.

Species

There are three amphiuma species, distinguished by the number of toes:
  • Three-toed Amphiuma
    Amphiuma tridactylum
    The Three-toed Amphiuma is a species of aquatic salamander native to the southeastern United States.- Description :...

     (Amphiuma tridactylum)
  • Two-toed Amphiuma
    Two-toed Amphiuma
    The two-toed amphiuma is a snake-like salamander found chiefly in the southeastern United States. It is commonly, but incorrectly, called "congo snake", "conger eel" or the "blind eel". It has a thick body about long, four vestigial legs that end in two or three toes which are virtually useless,...

     (Amphiuma means)
  • One-toed Amphiuma
    Amphiuma pholeter
    The One-toed Amphiuma is an aquatic, eel-like salamander native to the southeastern United States. It was unknown to science until 1950, when it was collected by herpetologist W. T. Neill...

    (Amphiuma pholeter)

External links

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