Two-lined toad viper
| Two-lined toad viper | ||||||||||||
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| Causus bilineatus | ||||||||||||
| Boulenger , 1905 |
The two-striped toad viper ( Causus bilineatus ) is one of six species of toad vipers (Causinae) within the vipers (Viperidae).
features
The two-lined toad viper reaches an average total length of 30 to 50 centimeters, the maximum length is documented 65 centimeters. The head is only slightly separated from the body, the muzzle is long and tapers to the tip.
The basic color is ash gray to brown or chestnut brown; the back shows many unevenly distributed, dark spots, some of which are almost rectangular, otherwise unevenly in shape. The speckle is located between two light stripes that stretch across the entire body from the neck to the tail and give the species its name. There is a V-shaped, dark drawing on the head, the tip of which lies on the frontal shield , and dark temporal ligaments extend from the eye to the corner of the muzzle. The ventral side is brown to dark brown in color.
The back scales are weakly keeled, with the middle of the body having 15 to 18 rows of scales around the body. The scales have a soft and velvety surface that gives the entire snake this impression. The ventral side of the females is covered from 128 to 144 and the males from 122 to 141 ventralia , followed by the anal shield and 18 to 30 subcaudalia .
distribution and habitat
The two-lined toad viper is distributed over parts of southern central Africa from the Democratic Republic of the Congo to northern Namibia and eastern Angola . There are two records from Zambia from the marshland south of Lake Bangweulus . As a habitat, the snake particularly prefers moist or wooded savannah areas .
Way of life
As with all toad vipers, relatively little is known about the way of life of this species. It feeds mainly on frogs and toads, especially clawed frogs ( Xenopus sp.), Which suggests that this species is more aquatic than all other toad vipers. Like other toad vipers, it is viviparous ( ovoviviparous ).
Systematics
The two-lined toad viper is one of six species of the only genus within toad vipers (Causinae). In addition to the primeval vipers (Azemiopinae) with the Fea viper ( Azemiops feae ) as the only species, as well as the species-rich pit vipers ( Crotalinae) and real vipers (Viperinae), these represent one of the subfamilies of the vipers (Viperidae).
Snake venom
About the poison of this kind there are no scientific studies. Toad vipers generally have a relatively weak poison for humans, which is only rarely used when catching prey. Despite the large poison glands, hardly any poison is injected into the prey; as a rule, small amounts of it drip from the poison teeth. Bites in humans only lead to local swelling and pain; no deaths from toad vipers are known.
Receipts and further information
Sources cited
Much of the information in this article is taken from Mallow et al. (2003), the following sources are also cited:
literature
- David Mallow, David Ludwig, Göran Nilson: True Vipers. Natural History and Toxicology of Old World Vipers. Krieger Publishing Company Malabar, Florida, 2003; Pages 20-21, ISBN 0-89464-877-2