Bothrops
Island - lance (Bothrops insularis )
The American Terciopelos ( Bothrops ) are a snake genus of the subfamily of pit vipers. The genus comes with about 37 species found in South and Central America. All species are poisonous, the common species with larger distribution area are among the medically most relevant poisonous snakes. Deaths are rare to often depending on the type.
- 6.1 Local effects
- 6.2 Systemic effects
- 6.3 Epidemiology
- 6.4 Medical Terms
- 7.1 Notes and references
- 7.2 Literature
Features
Physique
American Terciopelos are medium -sized to very large, relatively slender pit vipers, the broad head is distinct from the neck. Most species have a sharp canthus and a non- extended tip of the instrument. The three exceptions are, for example, a lojanus and B. barnetti in which the jaw tip is slightly curved upwards and B. ammodytoides that has a nose attachment. The smallest species reach full length of 50-70 cm, the most 2 m. Females are significantly larger and heavier than males.
Squamation
The species showing five to twelve weakly keeled Supraocularia. The number of supralabials is usually seven to nine, the number of Infralabialia usually nine to eleven. The number of ventral scales ( Ventralschilde ) varies 139-240, the number of Subcaudalia 30-86 and the number of dorsal scale rows in the middle of the body 21 to 29
Coloring
The basic color of the top is usually brown or gray. Most species show on both sides of the back light edged, dark brown, trapezoidal or triangular- shaped drawings whose wide and open at the bottom base shows the belly. The drawings can collide at the center back with the tips, so that the back shows a very striking X - drawing, or partially or completely offset from each other. On the tail of this drawing is almost always close and usually only consists of light gray bars on a dark background. A few species in southern South America are drawn in derogation of intense and contrast and also show a strong strip drawing of the head.
Distribution and habitat
American Terciopelos are largely confined to South America, only two of the approximately 37 species also reach Central America ( Bothrops asper and B. punctatus ). Most species are restricted to lowlands and occur at altitudes up to 1500 m, a number of species is very adaptable and inhabits a habitat range that reaches from desert-like coastal plains to mountain rainforests in 2500 m height. Some species are common in densely populated areas.
System
The number of species and subspecies has been controversial for a long time, Campbell and Lamar recognize 36 species and in addition a kind not previously described:
- Bothrops alcatraz Marques, Martins & Sazima 2002
- Bothrops alternatus Duméril, Bibron & Duméril 1854
- Patagonia - lance (Bothrops ammodytoides ) Leybold 1873
- Bothrops andianus Amaral 1923
- Terciopelo - lance (Bothrops asper ) Garman 1884
- Bothrops atrox Linnaeus 1758
- Bothrops barnetti Parker 1938
- Bothrops brazili Hoge 1954
- Bothrops caribbaeus Garman 1887
- Bothrops cotiara Gomes 1913
- Bothrops erythromelas Amaral 1923
- Bothrops fonsecai Hoge & Belluomini 1959
- Island - lance (Bothrops insularis ) Amaral 1922
- Bothrops itapetiningae Boulenger 1907
- Jararaca - lance (Bothrops jararaca ) Wied - Neuwied 1824
- Bothrops jararacussu Lacerda 1884
- Bothrops jonathani Harvey 1994
- Bothrops lanceolatus Bonnaterre 1790
- Bothrops leucurus Wagler 1824
- Bothrops lojanus Parker 1930
- Bothrops marajoensis Hoge 1966
- Bothrops moujeni Hoge 1966
- Bothrops muriciensis Ferrarezzi & Freire 2001
- Bothrops osbornei Freire - Lascano 1991
- Bothrops pictus Tschudi 1845
- Bothrops pirajai Amaral 1923
- Bothrops punctatus Garcia 1896
- Bothrops roedingeri Mertens 1942
- Bothrops sanctaecrucis Hoge 1966
- Bothrops venezuelensis Sandner - Montilla 1952
The main problems concerning the Artsystematik occur in so-called Bothrops neuwiedi complex, a group of Bothrops populations in the eastern and central South America. These populations were until very recently, all assigned to the species B. neuwiedi, up to 12 subspecies were of this type, therefore, accepted. Xavier da Silva led by a revision of this complex on the basis of morphological features, and split the complex in seven species:
- Bothrops Wagler neuwiedi 1824
- Bothrops diporus Cope 1862
- Bothrops lutzi Miranda - Ribeiro, 1915
- Bothrops marmoratus da Silva & Rodrigues 2008
- Bothrops mattogrossensis Amaral 1925
- Bothrops pauloensis Amaral 1925
- Bothrops pubescens Cope 1870
A molecular genetic analysis, which includes all species or taxa of the genus Bothrops, does not exist yet. In the most comprehensive molecular genetic work, which took into account 28 species or forms of the genus, the following cladogram was developed:
Bothrops pictus
Bothrops alternatus
Bothrops itapetiningae
Bothrops fonsecai
Bothrops cotiara
Bothrops neuwiedi eurutu
Bothrops erythromelas
Bothrops jararaca
Bothrops insularis
Bothrops taeniatus
Bothrops bilineatus
Bothrops pulcher
Bothrops jararacussu
Bothrops brazili
Bothrops punctatus
Bothrops caribaeus
Bothrops lanceolatus
Bothrops asper
Bothrops colombiensis
Bothrops marajoensis
Bothrops isabelae
Bothrops moujeni
Bothrops atrox
Bothrops pradoi
Lifestyle and diet
Almost all the species are mainly nocturnal. Occasionally diurnal are the one species that inhabit higher altitudes, for other kinds of dense tropical lowland rain forest on cloudy days or in the rain. The species live primarily on the ground, but a number of species also climbs often in low bushes or trees. Stronger arboreal punctatus are only a few species, especially B. insularis, B. jararaca, B. lanceolatus and B..
Most species eat as young cold-blooded animals such as invertebrates, reptiles and amphibians and change once they reach a sufficient size to warm-blooded vertebrates such as birds and mammals.
Reproduction
All species are viviparous, young are usually born in the rainy season. The reproduction is size- dependent. The smaller species have a maximum of about 20 pups per litter; for the largest species, B. asper, a maximum of 86 pups were detected in a litter.
Poison
Venoms of pit vipers are by far the most complex natural toxins. They contain a mixture of enzymes, low molecular weight polypeptides, metal ions and other, in their function so far poorly understood components. Just as diverse are the effects of these toxins. The poison of the American Terciopelos causes a whole range of symptoms, a distinction is made between local and the whole body in question ( systemic ) symptoms.
Local effects
The venom contains highly protein- degrading enzymes ( metalloproteinases and phospholipase A2) that destroy tissue. Typical local symptoms are especially severe pain, redness and swelling, which extend to the entire bitten limb and the adjacent hull very fast, and small or large blisters that contain clear or bloody, serous fluid. Often caused necrosis, especially of the muscle tissue. When too late or not initiated treatment affected limb must be amputated because of the occasional necrosis. More permanent damage are functional restrictions or losses by muscle wasting (atrophy ), permanent shortening of muscles and paralysis of peripheral nerves.
Systemic effects
The poison works by hemolytic and hemorrhagic metalloproteinases (blood vessels destructive). The most important Hämorrhagin in the venom of the species is Jararhagin, containing a zinc metalloproteinase. The poison caused by thrombin-like enzymes ( TLEs ) a change in the precursor fibrinogen clotting and thus a pathological activation of blood coagulation. This leads on further steps to rapid consumption of coagulation factors and therefore has anti-coagulant. The syndrome is known as Disseminated intravascular coagulopathy (DIC ). Patients bleeding from the bite site, that have not yet healed scars, insect bites and oral mucosa and leads to internal bleeding. The toxin appears to act directly nephrotoxic. Additional complications arise from infections caused by the bacteria flora contained in the mucous membranes of the snake. Deaths are due to acute renal failure, bleeding in the brain and blood poisoning.
Epidemiology
American Terciopelos are in South and Central America is by far the most relevant medical snakes. Fatal poisonings are rare and often depending on the type.
Medical Terms
The venom of Bothrops atrox Lanzenotter species Bothrops jararaca and contains, among other things, the enzyme reptilase, which is used because of its effect on blood coagulation in medicine both for diagnostic and for therapeutic purposes.