''Bothrops'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of highly venomous

pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeog ...

.McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1''. Herpetologists' League. 511 pp. (series). (volume). The generic name, ''Bothrops'', is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words , , meaning , and , , meaning or , together an allusion to the heat-sensitive

loreal pit The loreal pit is the deep depression, or fossa, in the Lore (anatomy), loreal area on either side of the head in pit vipers (crotaline snakes). The area is located behind the nostril and in front of the eye, but below the line that runs between ...

organs. Members of this genus are responsible for more human deaths in the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

than any other group of venomous snakes.Campbell JA, Lamar WW. 2004. ''The Venomous Reptiles of the Western Hemisphere''. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. . Currently, 48

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

are recognized.

Description

These snakes range from small, never growing to more than , to large at over in total length. Most are characterized by having a sharp '' canthus rostralis'' and an unelevated snout. The arrangement of the scales on top of the head is extremely variable; the number of interorbital scales may be 3–14. Usually there are 7–9

supralabials In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ( ...

and 9–11 sublabials. There are 21–29 rows of

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

at midbody, 139–240

ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that cont ...

, and 30–86 subcaudals, which are generally divided.

Common names

Lacépède originally applied the name "lanceheads" to all of these snakes, which he considered

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

. Thus, older writings, as well as popular and sometimes scientific writings (including the American Heritage, Merriam-Webster, and New Shorter Oxford dictionaries), still often call them ( French, "spearhead"). However, many scientists and hobbyists now restrict this name to the Martinican species, '' B. lanceolatus''. Other common names include American lanceheads and American lance-headed vipers.U.S. Navy. 1991. ''Poisonous Snakes of the World''. US Govt. New York: Dover Publications Inc. 203 pp. .

Geographic range

''Bothrops'' species are found in northeastern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

(

Tamaulipas Tamaulipas, officially the Free and Sovereign State of Tamaulipas, is a state in Mexico; one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 43 municipalities. It is located in nor ...

) southward through Central and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. They also occur on the islands of

Saint Lucia Saint Lucia is an island country of the West Indies in the eastern Caribbean. Part of the Windward Islands of the Lesser Antilles, it is located north/northeast of the island of Saint Vincent (Saint Vincent and the Grenadines), Saint Vincent ...

and

Martinique Martinique ( ; or ; Kalinago language, Kalinago: or ) is an island in the Lesser Antilles of the West Indies, in the eastern Caribbean Sea. It was previously known as Iguanacaera which translates to iguana island in Carib language, Kariʼn ...

in the

Lesser Antilles The Lesser Antilles is a group of islands in the Caribbean Sea, forming part of the West Indies in Caribbean, Caribbean region of the Americas. They are distinguished from the larger islands of the Greater Antilles to the west. They form an arc w ...

, as well as on Ilha da Queimada Grande off the coast of

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. ''B. atrox'' is also found on the island of

Trinidad Trinidad is the larger, more populous island of the Republic of Trinidad and Tobago, the country. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is the southernmost island in ...

in the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

off the eastern coast of

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

Behavior

Most species are nocturnal, although a few found at higher altitudes are active during the day. Otherwise, they may be seen on cloudy days or during periods of rain. Most are terrestrial, though all are capable of climbing. One species, ''B. insularis'', which is endemic to Ilha da Queimada Grande, is considered to be semi

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

. This species, unlike most ''Bothrops,'' preys primarily on birds, due to the absence of native mammal species on Queimada Grande. This feeding habit probably accounts for their more arboreal lifestyle compared with their mainland cousins. Many species of ''Bothrops'' exhibit tail vibration behavior when disturbed.Allf, Bradley C., Paul AP Durst, and David W. Pfennig. "Behavioral Plasticity and the Origins of Novelty: The Evolution of the Rattlesnake Rattle." The American Naturalist 188.4 (2016): 475-483

Venom

Members of this

are responsible for more fatalities in the

than any other group of

venomous snake ''Venomous snakes'' are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow ...

s. In this regard, the most important species are '' B. asper'', '' B. atrox'', and '' B. jararaca''. Without treatment, the fatality rate is estimated to be about 7%, but with treatment this is reduced to 0.5–3%. Bothrops ammodytoides

Typical symptoms of bothropic envenomation include immediate burning pain, dizziness, nausea, vomiting, sweating, headache, massive swelling of the bitten extremity, hemorrhagic blebs, local

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...

, bleeding from the nose and gums, ecchymosis, erythemia,

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

tachycardia Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ...

coagulopathy Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding ( bleeding diathesis), which may occur s ...

with hypofibrinogenemia and

thrombocytopenia In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coag ...

hematemesis Hematemesis is the vomiting of blood. It can be confused with hemoptysis (coughing up blood) or epistaxis (nosebleed), which are more common. The source is generally the upper gastrointestinal tract, typically above the suspensory muscle of du ...

, melena,

epistaxis A nosebleed, also known as epistaxis, is an instance of bleeding from the nose. Blood can flow down into the stomach, and cause nausea and vomiting. In more severe cases, blood may come out of both nostrils. Rarely, bleeding may be so significan ...

hematuria Hematuria or haematuria is defined as the presence of blood or red blood cells in the urine. "Gross hematuria" occurs when urine appears red, brown, or tea-colored due to the presence of blood. Hematuria may also be subtle and only detectable with ...

intracerebral hemorrhage Intracerebral hemorrhage (ICH), also known as hemorrhagic stroke, is a sudden bleeding into Intraparenchymal hemorrhage, the tissues of the brain (i.e. the parenchyma), into its Intraventricular hemorrhage, ventricles, or into both. An ICH is ...

, and

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

, secondary to hypotension and bilateral cortical necrosis. There is usually some discoloration around the bite site, and

rash A rash is a change of the skin that affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracke ...

es may develop on the

torso The torso or trunk is an anatomical terminology, anatomical term for the central part, or the core (anatomy), core, of the body (biology), body of many animals (including human beings), from which the head, neck, limb (anatomy), limbs, tail an ...

or the extremities. In general, death results from hypotension secondary to

blood loss Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, v ...

, kidney failure, and

intracranial The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull is also known as the cranium. The cranial cavity is formed by eight cranial bones known as the neurocranium that in human ...

hemorrhage. Common complications include necrosis and kidney failure secondary to shock and the toxic effects of the venom.

Species

* Not including the nominate subspecies.
^T

Type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

References

External links

* {{Authority control Snakes of South America Snakes of Central America Snake genera Taxa named by Johann Georg Wagler