Real vipers

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Real vipers
Adder (Vipera berus)

Adder ( Vipera berus )

Systematics
Order : Scale reptiles (Squamata)
without rank: Toxicofera
Subordination : Snakes (serpentes)
Superfamily : Adder-like and viper-like (Colubroidea)
Family : Vipers (Viperidae)
Subfamily : Real vipers
Scientific name
Viperinae
Oppel , 1811

The real vipers (Viperinae), sometimes also referred to as old world adders or vipers, form a subfamily within the vipers (Viperidae). The approximately 80 species are distributed in Europe, Asia and Africa, with most of the species living in the tropics and subtropics and only a few can also be found in the temperate latitudes. The northernmost species is the adder ( Vipera berus ), which is found in Scandinavia and extends beyond the Arctic Circle . All species of this taxon are poisonous. In contrast to the which also belongs to the vipers pit vipers (Crotalinae) they do not have a pit organ for the perception of heat radiation.

features

The real vipers include snake species with body lengths of around 20 centimeters such as the dwarf puff adder ( Bitis peringueyi ) up to over 2 meters such as the Gaboon viper ( Bitis gabonica ). The body is usually stocky and has a triangular head that is clearly separated from the body. In contrast to the snakes and poisonous snakes as well as some groups of vipers such as the fea viper ( Azemiops feae ) or the pygmy rattlesnakes ( Sistrurus ), which belong to the pit vipers, all types of small scales.

Real vipers, like all vipers, are venomous snakes. They have a corresponding poison apparatus with large poison glands behind the eyes, which are connected to the mostly large poison teeth in the front upper jaw via a poison channel . The teeth are so-called tubular poison teeth or solenoglyph teeth, which means that they have a completely closed poison channel in the tooth. They are surrounded by a dental sheath made of connective tissue, which retracts when the mouth is opened and reveals the unfolded teeth.

Way of life

Most species are adapted to life on the ground, only the species of bush vipers ( Atheris ) that live in the forests of Africa are pronounced tree inhabitants . These are equipped with a grasping tail and are therefore very good climbers. The terrestrial species can be found in all forms of the subsurface and are usually very specially adapted to them. There are pure desert species such as the dwarf puff adder ( Bitis peringueyi ) or the African horned vipers ( Cerastes ), which can move sideways on the desert sand, or burrowing species such as the Uzungwe viper ( Adenorhinos barbouri ).

Real vipers are mostly active during the day or at dusk. Above all, the European species of the temperate to moderately warm zone can be found almost exclusively during the day, while species of tropical Africa are more often active at dusk or at night. Due to the climatic conditions, Central to Northern European and Asian species also have periods of rest during winter, while these are not found in species from Africa and southern Asia. However, the phases of activity are less typical of the species in many European species, but can vary between populations in different habitats.

Most vipers feed on small mammals , which they actively chase and kill with one bite. Few species such as the Cycladic viper ( Macroektivena schweitzeri ) and individual populations of many other species specialize in hunting birds. Particularly large species such as the Gaboon viper ( Bitis gabonica ) also prey on porcupines , small monkeys , bats and small rams . In contrast, many small species feed partially or almost completely on arthropods and other small animals, including the meadow viper ( Vipera ursinii ) or the already mentioned Uzungwe viper .

With the exception of a few species, the real vipers are viviparous, the egg-laying species include large vipers ( Macroocket ), the Uzungwe viper and the Persian trughorn viper ( Pseudocerastes persicus ).

distribution and habitat

The representatives of the real vipers live in large parts of Africa without Madagascar , Asia including the Southeast Asian islands and Europe . In America and Australia no species of this group can be found. The evolutionary origin of the real vipers is probably in Africa, from there they have spread over their entire range today.

Among the real vipers there are some species with a very large distribution area, especially in Eurasia , including the chain viper ( Daboia russelii ) or the Levant otter ( Macrophia lebetina ), other species are only restricted to limited areas such as mountain ranges or islands such as the East African mountain otter ( Montatheris hindii ) or the Cycladic viper ( Macroektivena schweizeri ). Most species live in tropical and subtropical areas, only a few reach temperate latitudes and only the adder ( Vipera berus ) is distributed up to the northern polar circle .

Systematics

The real vipers traditionally include all vipers that do not have a pit organ. The toad vipers (Causinae) and the fea vipers ( Azemiops feae ) as the original representatives of the group were recognized as separate taxa through investigations into the morphology, in particular the cranial and genital morphology, as well as through molecular biological investigations and are no longer assigned to the real vipers today . The monophyly of the remaining species, that is, their common descent from a common ancestral species, is now considered to be confirmed by these investigations.

Within the real vipers, around 80 species are divided into twelve genera. Most of the species belong to the real otters ( Vipera ), others contain only one species such as Montatheris and Proatheris and are correspondingly monotypical. Especially within the Real otters several revisions have been made, from which new genres such as in the recent past macrovipera ( Macrovipera ) and the Oriental otters ( Daboia ) emerged, a number of other revisions were proposed.

Snake venom

Chain viper ( Daboia russelli )

Most viper poisons are primarily hemotoxic and / or cytotoxic . They affect blood , blood vessels and tissue , for example through various proteases . The toxins can lead to tissue destruction ( necrosis ), internal bleeding, local pain and swelling. Often they contain proteins that suppress hemostasis (blood clotting) through various mechanisms and, in some cases together with the tissue-destroying components, cause internal bleeding. Bleeding occurs under the skin, in the nasal and oral cavities, as well as in the intestines and brains of the prey. Some species also produce neurotoxic compounds that act on the victim's nervous system and cause paralysis.

swell

Sources cited

Most of the information in this article has been taken from the sources given under literature; the following sources are also cited:

  1. ↑ Herrmann, H.-W., U. Joger & G. Nilson (1992): Phylogeny and systematics of viperine snakes. III: resurrection of the genus Macroektivena (Reuss, 1927) as suggested by biochemical evidence. Amphibia-Reptilia, 13: 375-392
  2. ↑ Lenk, P., S. Kalayabina, M. Wink & U. Joger (2001): Evolutionary relationships among the true vipers (Reptilia: Viperidae) inferred from mitochondrial DNA sequences. Molecular Phylogenetics and Evolution 19: 94-104. ( Full text PDF )

literature

  • David Mallow, David Ludwig, Göran Nilson: True Vipers. Natural History and Toxicology of Old World Vipers. Krieger Publishing Company Malabar, Florida, 2003. ISBN 0-89464-877-2
  • Ulrich Gruber: The snakes in Europe and around the Mediterranean . Franckh'sche Verlagsbuchhandlung, Stuttgart 1989, ISBN 3-440-05753-4
  • Ulrich Joger, Nikolai Stümpel: Handbook of the reptiles and amphibians of Europe; Volume 3 / IIB, Snakes (Serpentes) III Viperidae. Aula-Verlag, Wiebelsheim 2005. ISBN 3-89104-617-0

Web links

Commons : Real Vipers (Viperinae)  - Collection of pictures, videos and audio files