Typhlonectidae

Typhlonectidae
Typhlonectes natans
Systematics
Sub-stem : Vertebrates (vertebrata) Superclass : Jaw mouths (Gnathostomata) Row : Land vertebrates (Tetrapoda) without rank: Amphibians (Lissamphibia) Order : Sneak amphibian (Gymnophiona) Family : Typhlonectidae
Scientific name
Typhlonectidae
Taylor , 1968

The Typhlonectidae are a family of the sneak amphibians (Gymnophiona) that lives disjointly in South America. The animals occur in the Amazon region and in the Orinoco river basin , also in the Río Magdalena , in the tributaries and on the coast of Lake Maracaibo . The species of the genus Chthonerpeton live in the area of ​​the Río de la Plata . Some taxonomists assign the family as a subfamily Typhlonectinae to the Caeciliidae .

features

The Typhlonectidae are 14 to 75 centimeters long. The skull, like that of the burrowing sneak, consists of a few firmly fused bones. The nasal bone and intermaxillary bone are fused. The mouth is below. The choans have valve flaps. Typhlonectids are scaly and tailless, at the end of the body there is only a single terminal scale. The back of the body is flattened at the sides to adapt to movement in the water. The body is curled by completely or partially surrounding skin folds (annuli). There are only primary annuli. Aquatic species have a low, fin-like fold of skin on their back that runs from the head to the terminal scale. All typhlonectids except Atretochoana eiselti have tracheal lungs . Atretochoana eiselti is the only caecum without a lung and, with a length of 70 to 100 centimeters, it is also the largest lungless terrestrial vertebrate. So far (as of 2012) the species is only known from seven specimens.

Way of life

Some species are aquatic, others semi-aquatic. Aquatic species are also occasionally outside the water. All are good at digging in sand, gravel and mud soils, but have lost the ability to move in a straight line with undulating movements of the skin muscle tube. All species are viviparous and have fully developed young that no longer have to go through metamorphosis .

Genera and species

Chthonerpeton indistinctum

There are five genera with 13 species:

• Genus Atretochoana
  • Atretochoana eiselti
• Genus Chthonerpeton
  • Chthonerpeton arii
  • Chthonerpeton braestrupi
  • Chthonerpeton exile
  • Chthonerpeton indistinctum
  • Chthonerpeton noctinectes
  • Chthonerpeton onorei
  • Chthonerpeton perissodus
  • Chthonerpeton viviparum
• Genus Nectocaecilia
  • Nectocaecilia petersii
• Genus Potamotyphlus
  • Potamotyphlus kaupii
• Genus Typhlonectes
  • Typhlonectes compressicauda
  • Typhlonectes natans

literature

• Werner Himstedt: The blind diggers . ISBN 3894324341
• Wilfried Westheide & Reinhard Rieger: Special Zoology Part 2: Vertebrae and Skull Animals , 1st edition, Spectrum Akademischer Verlag Heidelberg • Berlin, 2004, ISBN 3-8274-0307-3

Web links

Commons : Typhlonectidae  - collection of images, videos and audio files

• Amphibiaweb.org
• Amphibian Species of the World Online Reference

Individual evidence

1. ↑ Bizarre Animal - Lurch without a lung on Spiegel Online on August 3, 2012