Eel newts
| Eel newts | ||||||||||||
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Two- toed eel newt ( Amphiuma means ) |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Amphiumidae | ||||||||||||
| JE Gray , 1825 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Amphiuma | ||||||||||||
| Garden , 1821 |
The eel newts ( Amphiuma ), also called fish newts , are the only genus of the family Amphiumidae . They are exclusively in the water, sometimes up to over a meter long, primeval tailed amphibians from coastal swamps and ponds in the south and southeast of the USA .
features
Eel newts have an elongated, cylindrical ( eel-like ) body, a pointed head with lidless, small eyes and reduced, only a few millimeters long limbs with one to three toes and sometimes only one finger. In large specimens with a length of 1 m, these can be approx. 2-3 cm in size. According to their number, three species are described whose ways of life are completely the same. The color is uniformly gray-brown or slate-gray on the top and light gray on the ventral side. The spine consists of 63 amphicoelic vertebrae, i.e. H. with vertebral bodies vaulted at both ends, of which only the anterior ribs have. They have lungs with a very long windpipe , but also four gill arches , each with a gill hole on both sides of the head. Eel newts have the largest red blood cells among vertebrates .
Depending on the species, a total length of 30 to 115 centimeters is achieved. The largest specimens can weigh up to 1.25 kilograms.
distribution
Eel newts are found in the warmer, calm and weedy waters of the southeastern coastal plains of the USA near the Gulf of Mexico and in the Mississippi lowlands north to the Missouri River . Their range overlaps with that of the arm newts .
Way of life
The animals are nocturnal; During the day they hide between aquatic plants and other shelters in the water, which they visit again and again. At night they come out and look at the bottom for aquatic insects , worms , small fish, snakes, frogs, molluscs and crustaceans . Even smaller conspecifics are hunted. Like the eels, they swim neatly in the water and also like to burrow in the mud. In rainy weather and floods, they occasionally leave the residential water and crawl around on wet meadows. They are very vicious and are often mistakenly believed to be poisonous by the population.
Eel newts are sometimes eaten and they are caught in shallow water with fake nets or simply with the hand and rough, hard and high gloves. If the animals are kept captive, they adapt quickly to this way of life and also get used to taking food from the hand of the keeper during the day. However, they are rarely kept as pets. Their natural enemies, which occur in the same habitat, include two species of snakes, the rainbow mud snake and the mud snake .
Reproduction
During the mating season between January and May, several females compete for the favor of a male. Finally, the partners entwine, and the male transfers - unlike the other tail amphibians - the spermatophores directly into the female's cloaca . The female later rolls ashore to lay several hundred eggs in two strings in damp places and to “incubate” or guard this “nest” for about 5 months. The four to six centimeters long larvae that hatch with their gills and limbs are finally washed into the water by rainfall or rising water levels. 4 months later, in early spring, the larva begins to transform, during which the outer gills disappear and the lungs take up their function. However, four gill arches and one gill hole remain. This lies between the 3rd and 4th gill arch. Their development therefore includes an incomplete metamorphosis (partial neoteny ) in contrast to the axolotl or other newt larvae .
Taxonomy
- Genus eel newts , Amphiuma Garden, 1821
- Art two- toed eel newt ,
- Art single- toed eel newt , Amphiuma pholeter Neill, 1964
- Species three- toed eel newt , Amphiuma tridactylum Cuvier, 1827
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See also: Systematics of Amphibians , with references to the amphibian taxonomy used here. |
literature
- The modern animal lexicon. Volume 1, Bertelsmann Lexikon Institut, pp. 9-10.
Web links
- Handbook of Paleoherpetology , accessed March 13, 2014
Remarks
- ↑ Aalmolche , in: Großes Lexikon der Tiere , special edition, Lingen Verlag, Cologne 1989, vol. 1, p. 15.