Crescent lance viper
| Crescent lance viper | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Crescent Lance Viper ( Bothrops alternatus ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Bothrops alternatus | ||||||||||||
| Duméril , Bibron & Duméril , 1854 |
The Crescent Lanzenotter ( Bothrops alternatus ), also Urutu called, is a viper out of the subfamily of pit vipers and belongs to the genre of American Terciopelos ( Bothrops ).
features
Bothrops alternatus reaches a total length of about 90 cm, maximum between 140 and 170 cm. The physique is strong and the trunk of adult animals is wider than it is high in cross section. The head is flat, angular, pointed towards the tip of the snout, triangular in shape when viewed from above and clearly set off from the neck. The eye has a pupil that is vertically slit when exposed to light. A light spot can be seen on the top of the head, which represents a cross or double cross, as well as a light temple band. The upper and lower lip shields are whitish. The body has a light gray to brown basic color. It is marked by 24 to over 27 paired or alternately arranged and white-edged crescent moon spots. These spots follow one another at close intervals and partly touch each other over the middle of the back. The ventral side is spotted black and yellow. In general, the drawing of the body and head in Bothrops alternatus is variable. As is typical for vipers, the venom apparatus consists of venom glands located on the side of the skull (specialized salivary glands ) and movable fangs located in the anterior upper jaw (solenoglyph tooth position).
Pholidosis
The pholidosis (scaling) shows the following characteristics:
- 8 to 10 upper lip shields ( supralabials ),
- 12 to 14 lower lip shields ( sublabials ) and
- 23 to 37 (mostly 27 to 33) rows of strongly keeled trunk scales ( Scuta dorsalia ).
Systematics
The first description of Bothrops alternatus carried out in 1854 by the French zoologist André Marie Constant Duméril , Gabriel Bibron & Auguste Duméril . The systematics of the genus Bothrops is the subject of research. On the basis of molecular biological studies, among other things , Fenwick et al. (2009) and Wallach et al. (2014) suggested splitting the genus. Bothrops alternatus would be transferred to the genus Rhinocerophis under the name Rhinocerophis alternatus .
distribution
The distribution area in South America includes regions in Argentina ( Buenos Aires , La Pampa , Santa Fe , Entre Rios , Corrientes , Misiones , Chaco , Formosa , Córdoba , Santiago del Estero , Catamarca , Tucumán , San Luis ), Uruguay , Paraguay and Brazil ( Rio Grande do Sul , Santa Catarina , Paraná , São Paulo , Minas Gerais , Goiás , Mato Grosso do Sul ). The climate within the distribution area varies from tropical to subtropical to temperate . The populated biotopes are mostly close to water and are represented by open terrain in deciduous forests, pampas , fields, rocky areas or swamp areas. Bothrops alternatus is occasionally found on agricultural land (e.g. sugar cane plantations) or in human settlements. Observations are mostly made between October and December, often at night and on the streets.
Bothrops diporus occurs regionally sympatric with Bothrops alternatus .
Way of life
.jpg)
Bothrops alternatus leads a ground-dwelling and largely nocturnal way of life. During the day, for example, it hides between roots, under fallen leaves, under wood or in animal structures. The range of prey primarily includes small mammals, especially rodents . When disturbed, Bothrops alternatus often hides their head under the loops of their body. When provoked, she may defend herself aggressively and with poisonous bites. The front body can be thrown like a lance, so that the range is great in the event of a bite.
The mating season extends over the months of September and October. The propagation is done by ovoviviparity , so egg-viviparous. Litters with a circumference of 44 young snakes were documented in captivity. The young snakes measure around 20 cm at birth.
Snake venom
According to Minton (1974), the yield of a poison bite is 60 to 100 mg of poison secretion (dry weight).
ingredients
The poison of Bothrops alternatus , like that of most pit vipers, has a very complex composition and contains, as pharmacologically active components, substances that have an influence on hemostasis (pro and anticoagulants), cytotoxins and hemorrhagins ( metalloproteases that damage blood vessels ).
Noteworthy individual substances are:
- Alternagin : zinc metalloprotease, has hemorrhagic effects ( damage to blood vessels, bleeding) and blocks integrin alpha-2 / beta-1 (ITGA2 / ITGB1), which effectively inhibits the collagen- induced platelet aggregation . Other effects include influencing the chemotaxis of neutrophilic granulocytes and inhibiting angiogenesis (high concentrations).
- Bhalternin : enzyme from the group of thrombin- like snake venom serine proteases ; in animal studies (mouse, intraperitoneal administration) show, among other things fibrinolysis , hemolysis (heart), glomerular blockages in kidney tissue and necrosis and inflammation in the liver tissue .
- Basic phospholipase A2 homologous BaTX: Phospholipase A2 homologous protein. Has no enzymatic activity, but acts as a potent myotoxin . As such, it leads to massive necrosis in animal experiments after injection into muscle tissue. Furthermore, it has a neurotoxic effect by inhibiting the activity of motor nerve endings. The mean lethal dose of the toxin was determined to be 7 mg / kg (mouse, intravenous ).
toxicology
A poison bite must be viewed as potentially life threatening. Possible non-specific general symptoms are headache, abdominal pain, cramps and dizziness. Local swelling , blistering , necrosis ( amputation may be necessary) and bleeding are key symptoms of poisoning after a poison bite by Bothrops alternatus . When the coagulation factors are used up, disseminated intravascular coagulopathy can occur. Secondary damage to the kidneys cannot be ruled out. Toxins and blood loss can cause shock and circulatory failure . Various antivenins , such as 'Polyvalent Antivenom' (Instituto Clodomiro Picado, Costa Rica) or 'Soro antibotropico-laquetico' (Instituto Butantan, Brazil), are available for therapy.
With adequate medical care, a low mortality rate can be assumed.
Individual evidence
- ↑ a b Bothrops alternatus in The Reptile Database (accessed July 5, 2018)
- ↑ a b c University of Adelaide, Clinical Toxinology Resources: Bothrops alternatus (accessed July 5, 2018)
- ↑ UniProt: Zinc metalloproteinase-disintegrin-like alternagin (accessed on July 5, 2018)
- ↑ UniProt: Thrombin-like enzyme bhalternin (accessed on July 5, 2018)
- ↑ UniProt: Basic phospholipase A2 homolog BaTX (accessed on July 5, 2018)
literature
- Ludwig Trutnau: Snakes in the Terrarium Vol. 2: Poisonous snakes . Verlag Ulmer, Stuttgart 1998, ISBN 3-800-1705-23 .
