Dwarf puff adder
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Dwarf puff adder ( Bitis peringueyi ) |
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| Bitis peringueyi | ||||||||||||
| ( Boulenger , 1888) |
The Peringuey's Adder ( Bitis peringueyi ; English Sidewinder Snake ), also Namib Viper is a snake of the genus Puffottern ( Bitis Gray, 1842). It is the only viper to live in the Namib Desert , which stretches from the coast of Namibia to southern Angola . With a maximum body length of only about 30 centimeters, it is one of the smallest species of the genus, along with Schneider's dwarf puff adder ( Bitis schneideri ). It is one of the so-called Little Five ("small five"; see Big Five ).
features
The dwarf puff adder reaches an average length of 20 to 25 centimeters and a maximum body length of about 32 centimeters, with the females becoming longer and heavier than the males. This makes it the smallest species within the puff adder. The snake has a stocky body with a broad and rounded head and upturned eyes. The head is covered by small, strongly keeled scales, the eyes are separated by six to nine scales and each surrounded by ten to thirteen scales. The lower eye shields (subocularia) are separated from the 10 to 14 upper lip shields (supralabiala) by two to four rows of scales. In addition, the snake has 10 to 13 lower lip shields (sublabials), of which the first two to four touch the chin scales. The head is sand-colored and can have small black spots or a triangular forehead spot.
The color is gray-yellow to light reddish-brown with three longitudinal rows of indistinct spots and irregularly distributed small dark spots. The ventral side is light from whitish to yellow and sometimes has red-brown or black spots. The tail is mostly sand-colored, but around 25 percent of the animals have a black tail tip. In the middle of the body, the snakes have 23 to 31 rows of strongly keeled scales, with only the bottom row in contact with the ventral scales being keeled and made up of particularly large scales. The snake has 117 to 144 abdominal scales (ventralia), which are followed by the undivided anal shield and 15 to 30 under- tail scales (subcaudalia). The males have 117 to 138 ventral scales and 22 to 30 under-tail scales while the females have 125 to 144 ventral and only 15 to 25 under-tail scales.
distribution and habitat
The miniature puff adder lives in the Namib Desert and adjacent areas from southern Angola to southern Namibia near Lüderitz and Rotkuppe . The species was first described on a specimen "from Damaraland , about 10 kilometers east of Walvis Bay " ( Terra typica ).
The Namib Desert, with its high daytime temperatures and temperature fluctuations between day and night and especially the drought as a habitat, is one of the most extreme habitats in Africa. Daytime temperatures can be well above 50 ° C, while nighttime temperatures are below freezing point. Plants and animals are exposed to extreme living conditions due to decades of dry periods and frequent sandstorms.
Way of life
Like many desert dwellers , this species is also predominantly crepuscular and nocturnal, although it can also be found during the day on foggy days, especially near the coast. During the day it lies buried in the sand, if possible in a shady place under tufts of dune grass ( Stipagrostis sabulicola ). The eyes, nostrils and tip of the tail protrude from the sand. When a potential prey animal approaches, the tip of its tail is moved "like an insect", especially by individuals with black tails, in order to lure and grab the animal within reach.
The miniature puff adder masters the so-called cross winds in order to move quickly over loose sand, which makes it recognizable as a real desert snake. This form represents the snake's preferred mode of locomotion and is used regardless of the ground, while the dwarf puff adder can only be seen crawling when climbing on low bushes or rocks.
When threatened, this viper hisses and also bites, but its bite only causes local pain and swelling in humans.
nutrition
The diet of the puffin adder consists mainly of desert lizards of the genera Meroles and Aporosaurus as well as the sand geckos of the genus Ptenopus . Smaller rodents, especially the two species Gerbillurus tytonis that occur in the Namib Desert and the diurnal Rhabdomys pumilio , can also be used as food.
A large part of the necessary fluid is absorbed with food, especially through Aporosaurus , whose body stores up to 75% of its body weight water. Since precipitation in the form of rain is extremely rare in the Namib, the dwarf puff adder can also use the dew to absorb liquid by lying flat on the sand at night and licking the moisture that condenses on the rough body surface. However, due to the extreme efficiency of the kidneys , water intake through food is usually sufficient.
Reproduction and development
Observations on the reproduction of the dwarf puff adder are very rare, which means that the information is also very sparse. The species is ovoviviparous and in March or April gives birth to a maximum of ten young animals that are about 10 to 13 centimeters long and weigh between 1.6 and 1.7 grams. These are covered by a thin egg membrane, from which they free themselves with the help of jerky movements of the head.
Immediately after they have left the egg shell, they are able to move independently crosswinds. The first molt usually occurs within the first hour of life. After just a few days, the young snakes are independently hunting small lizards.
Taxonomy
The first description of the dwarf puff adder was under the name Vipera peringueyi by the French naturalist George Albert Boulenger in 1888 on the basis of several snakes that were collected in the area east of Walvis Bay, Namibia. As early as 1896 he assigned the snake to the puff adders ( Bitis ) as Bitis peringueyi .
The miniature puff adder is one of 16 species within the puff adder. It is closely related to the horned puff adder ( B. caudalis ), which also lives in desert areas of Africa, especially in the Kalahari and the South African semi-desert region Karoo . The anatomical similarities of both species have been confirmed by studies on a molecular biological level. Both together again ask the sister group of a taxon of mountain-puff adder ( B. atropos ) and tufts Brow puff adder ( B. cornuta ). These and other small Puffotterarten be within the genus in a subgenus Calechidna arranged that the large species such as the puff adder ( B. arietans ) in the subgenus Bitis and the gaboon viper ( B. gabonica ) and the rhinoceros viper ( B. nasicornis ) in the subgenus Macrocerastes .
Snake venom
Very little is known about the poison of the dwarf puff adder, as no scientific analysis has yet been carried out. It is not considered to be dangerous and the few cases where people have been bitten were all localized pain and swelling. Specific antivenins do not exist, bites are treated with analgesics and antibiotics to prevent infection of the wound.
literature
- David Mallow, David Ludwig, Göran Nilson: True Vipers. Natural History and Toxicology of Old World Vipers , Krieger Publishing Company, Malabar (Florida) 2003, pages 92-95, ISBN 0-89464-877-2
Web links
- Bitis peringueyi in The Reptile Database
- Bitis peringueyi inthe IUCN 2013 Red List of Threatened Species . Submitted by: Joger, U. & Turner, AA, 2010. Retrieved September 2, 2013.
Individual evidence
- ↑ The little five in a land of sand. Africa Geographic, December 8, 2015.
- ↑ Jessica J. Hughes, David Ward, Michael R. Perrin: Predation Risk and Competition Affect Habitat Selection and Activity of Namib Desert Gerbils. Ecology 75 (5), 1995; Pages 1397-1405 ( abstract )
- ↑ 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 )
