Giant salamander

Japanese giant salamander ( Andrias japonicus )

The giant salamander ( Cryptobranchidae ) are a very primitive order of Salamanders. It is dauer larvae with a partial conversion (see: partial neoteny ). The two genera are tart spread over East Asia and North America. In the Miocene the genus Andrias also in Europe today came before. Their closest relatives are the angles tooth newts ( Hynobiidae ).

Features

The spine of the giant salamander consists of amphicoelen (front and back hollowed ) vertebrae; her skull bone has no tears legs. They have four trained quite short limbs and stand out with their massive, fleshy shape and its extremely broad, flat head and body. Trunk, limbs and laterally flattened, relatively short tail wearing wide Hautsäume or beads. The eyes far-out are very small, lidless and degenerate their performance. The two Asian giants salamander species with body lengths up to 1.5 meters and weighing more than 20 kg then the largest and heaviest extant amphibians at all; the American mud devil is about half the size. For the Chinese giant salamander is postulated even a length of up to 180 centimeters; whether this information can be found from the 1930s in present-day specimens yet, but is questionable.

The information presented in the youth outer gills are largely regressed in the third year, soft lung, skin and intestine breathing. In the genus Cryptobranchus remain from the four inner gill arches of the larval phase, however, two more, with the gill holes are closed; at Andrias a pair remains open. Also the lack of eyelids and keeping the Larvenbezahnung in adult animals are features of an incomplete metamorphosis. Instead of vision touch and smell play an important role.

Occurrence of life

In 1726 the Swiss Johann Jakob Scheuchzer found ( 1672-1733 ), Zurich city physician and naturalist, which is about a meter tall fossilized skeleton of a living 14 million years ago giant salamander ( Andrias scheuchzeri ) on Schienerberg in the Oehninger limestones, today the district of Konstanz, Baden- Württemberg. However Scheuchzer believed at the time to have the skeleton of a perished at the Flood humans (Homo diluvii ) before him. That this is indeed a giant salamander extinct in the skeleton, was not recognized until 1837 by Johann Jakob von Tschudi.

Giant salamanders inhabit life aquatil clean, cool streams and partly also major rivers and mountain lakes. They appear quite sluggish and lurking hidden on the ground after passing prey animals such as fish, other newts, frogs, crustaceans, earthworms and aquatic insects. Mostly they are active at night.

Andrias davidianus is widespread in southeast China, Andrias japonicus in southern and central Japan. Cryptobranchus alleganiensis comes in the eastern and central USA (in the subspecies ssp. Alleganiensis the south and southwest of the State of New York, in southern Illinois, the Northeast Mississippi and in the north by Alabama and Georgia, the disjunct subspecies ssp. Bishopi in the southeast of Missouri and Arkansas).

Reproduction

The increase in late summer occurs in a very peculiar manner for amphibians. The male scrapes a shallow nest from the ground into which it can then enter spawning females ready. This place two each from several meters long spawning cords of up to 600 elongated eggs, which are then immediately inseminated by the male. The nest is guarded by the Father; the females are as potential spawning eater kept away now. The larvae hatch after two to three months with a size of three centimeters and existing gill tufts and limbs.

Species protection

The genus Andrias be listed in Annex I of the Washington Convention ( CITES). Any trade in such animals is prohibited.

Taxonomy

• Aviturus genus ( genus ) Gubin, 1991 - Early Giant Salamander Type Aviturus Exsecratus ( Gubin, 1991) † - † Mongolian giant salamander, lived 56 million years in Mongolia

• Type Andrias davidianus ( Blanchard, 1871) - Chinese Giant Salamander
• Andrias japonicus type ( Temminck, 1836) - Japanese Giant Salamander
• Type Andrias scheuchzeri ( Tschudi, 1837) †

• Type Cryptobranchus alleganiensis ( Daudin, 1803) - Mud Devil, Hell Bender

Others

• Since giant salamanders are considered a delicacy in their Asian homeland and also find use in folk medicine, they were hunted almost to extinction by bait fishing. Their habitats were partially destroyed or often dirty. Today, they are at least in Japan under protection.
• The first Japanese giant salamander was first brought in 1829 by Philipp Franz von Siebold to Europe, specifically to Leiden, where he continued to live even 52 years. This suggests that these animals can be very old. Giant salamander have since sought objects on display for Zoological Gardens. So already pointed Baedeker 1863 tape Belgium and Holland on a copy of " Cryptobranchus japonicus " as a special attraction in the Amsterdam zoo go, that does not even possess the London Zoo.
• Mud devils are very valiant, humans quite snappy when they feel threatened.
• The Name Is Mud devil for Cryptobranchus alleganiensis comes from German -born American emigrants who deeply despised these animals. If the animals are attacked in their clear waters with rods, they make fierce resistance and stir up mud on. In the language of Native Americans, the animals are called " water dogs".
• The eponymous pigs in the novel War with the Newts by Czech writer Karel Čapek also be allocated on the type Andrias scheuchzeri.