Bothrops is a genus of highly venomous pit vipers endemic to the Neotropics.[1] The generic name, Bothrops, is derived from the Greek words Greek, Modern (1453-);: βόθρος,, meaning, and Greek, Modern (1453-);: ὄψ,, meaning or, together an allusion to the heat-sensitive loreal pit organs. Members of this genus are responsible for more human deaths in the Americas than any other group of venomous snakes.[2] Currently, 48 species are recognized.
These snakes range from small, never growing to more than 50–, to large at over 200cm (100inches) in total length. Most are characterized by having a sharp canthus rostralis and an unelevated snout.[2]
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 and 9-11 sublabials. There are 21-29 rows of dorsal scales at midbody, 139-240 ventral scales, and 30-86 subcaudals, which are generally divided.[2]
Lacépède originally applied the name "lanceheads"[2] to all of these snakes, which he considered conspecific. 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 fer-de-lance (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.[3]
Bothrops species are found in northeastern Mexico (Tamaulipas) southward through Central and South America to Argentina. They also occur on the islands of Saint Lucia and Martinique in the Lesser Antilles, as well as on Ilha da Queimada Grande off the coast of Brazil.[1] B. atrox is also found on the island of Trinidad in the Caribbean off the eastern coast of Venezuela.
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. 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.[2] Many species of Bothrops exhibit tail vibration behavior when disturbed.[4]
Members of this genus are responsible for more fatalities in the Americas than any other group of venomous snakes. 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%.[2] Typical symptoms of bothropic envenomation include immediate burning pain, dizziness, nausea, vomiting, sweating, headache, massive swelling of the bitten extremity, hemorrhagic blebs, local necrosis, bleeding from the nose and gums, ecchymosis, erythemia, hypotension, tachycardia, coagulopathy with hypofibrinogenemia and thrombocytopenia, hematemesis, melena, epistaxis, hematuria, intracerebral hemorrhage, and kidney failure, secondary to hypotension and bilateral cortical necrosis. There is usually some discoloration around the bite site, and rashes may develop on the torso or the extremities.[2]
In general, death results from hypotension secondary to blood loss, kidney failure, and intracranial hemorrhage. Common complications include necrosis and kidney failure secondary to shock and the toxic effects of the venom.[2]
| Image | Species | Subsp.* | Common name | Geographic range |
|---|---|---|---|---|
| B. alcatraz | 0 | Alcatrazes lancehead | Alcatrazes Island, São Paulo state, Southeastern Brazil. | |
| B. alternatus | 0 | Urutu, yarará, víbora de la cruz | Southeastern Brazil, Paraguay, Uruguay and northern Argentina (in the provinces of Buenos Aires, Catamarca, Córdoba, Corrientes, Chaco, Entre Ríos, Formosa, La Pampa, Misiones, San Luis, Santa Fe, Santiago del Estero and Tucumán. | |
| B. ammodytoides | 0 | Patagonian lancehead | Argentina in the provinces of Buenos Aires, Catamarca, Córdoba, Chubut, La Pampa, La Rioja, Mendoza, Neuquén, Río Negro, San Juan, San Luis, Santa Cruz and Tucumán | |
| B. asper | 0 | terciopelo (preferred), Fer-de-lance (commonly used, but incorrect) | Atlantic lowlands of eastern Mexico and Central America, including Guatemala, Belize, Honduras, Nicaragua, Costa Rica and Panama, a disjunct population occurs in southeastern Chiapas (Mexico) and southwestern Guatemala, northern South America in Colombia and Ecuador West of the Andes, westernmost Venezuela, and Tumbes, Peru. | |
| B. atrox | 0 | Common lancehead | Tropical lowlands of South America east of the Andes, including southeastern Colombia, southern and eastern Venezuela, Trinidad, Guyana, Suriname, French Guiana, eastern Ecuador, eastern Peru, northern Bolivia and the northern half of Brazil | |
| B. ayerbei | 0 | Patian lancehead, Ayerbe's lancehead | Cauca, Colombia | |
| B. barnetti | 0 | Barnett's lancehead | Along the Pacific coast of northern Peru at low elevations in arid, tropical scrub | |
| B. bilineatus | 1 | Two-striped forest-pitviper | Amazon region of South America: Colombia, Venezuela, Guyana, Suriname, French Guiana, Brazil, Ecuador, Peru and Bolivia. An isolated population is known from the Atlantic versant of southeastern Brazil. | |
| B. brazili | 0 | Brazil's lancehead | Equatorial forests of eastern Peru, eastern Ecuador, Brazil and northern Bolivia | |
| B. caribbaeus | 0 | Saint Lucia lancehead | St. Lucia, Lesser Antilles, apparently restricted to the low elevation periphery of all but the southern third and extreme northern tip of the island | |
| B. chloromelas | 0 | Inca forest-pitviper | central Andes of Peru | |
| B. cotiara | 0 | Cotiara | Araucaria forests of southern Brazil in the states of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul, northeastern Argentina in Misiones Province | |
| B. diporus | 0 | Painted Lancehead | Argentina, Brazil, Paraguay, Bolivia | |
| B. erythromelas | 0 | Caatinga lancehead | Northeastern Brazil in the states of Alagoas, Bahia, Ceará, extreme eastern Maranhão, Minas Gerais, Paraíba, Pernambuco, Piauí, Rio Grande do Norte and Sergipe | |
| B. fonsecai | 0 | Fonseca's lancehead | Southeastern Brazil in the states of northeastern São Paulo, southern Rio de Jeneiro and extreme southern Minas Gerais | |
| B. germanoi | 0 | Moela's lancehead | Ilha da Moela, Brazil | |
| B. insularis | 0 | Golden lancehead | Queimada Grande Island, São Paulo State, Brazil | |
| B. itapetiningae | 0 | São Paulo lancehead | Southeastern Brazil in the states of Minas Gerais, Mato Grosso, São Paulo, and on the Paraná Plateau | |
| B. jabrensis | 0 | Jabre's lancehead | Paraíba, Brazil | |
| B. jararaca | 0 | Jararaca | Southern Brazil, northeastern Paraguay and northern Argentina (Misiones) | |
| B. jararacussu | 0 | Jararacussu | Eastern Brazil (from Bahia to Santa Catarina), Paraguay, southeastern Bolivia and northeastern Argentina (Misiones Province) | |
| B. jonathani | 0 | Jonathan's lancehead, Cochabamba lancehead | The Altiplano of central Bolivia in the departments of Cochabamba, Santa Cruz and Tarija, and in northwestern Argentina in the departments of Jujuy and Salta, occurring at elevations of 2000–3500 m in dry, rocky grassland | |
| B. lanceolatusT | 0 | Fer-de-lance, Martinique lancehead | Martinique, Lesser Antilles | |
| B. leucurus | 0 | Whitetail lancehead, Bahia lancehead | Eastern Brazil along the Atlantic coast from northern Espírito Santo north to Alagoas and Ceará, occurs more inland in several parts of Bahia, uncertain identity of disjunct populations west of the Rio São Francisco | |
| B. lutzi | 0 | Cerrado lancehead | Northeastern Brazil in northern Piaui state | |
| B. marajoensis | 0 | Marajó lancehead | Northern Brazil in the coastal lowlands of the Amazon Delta | |
| B. marmoratus | 0 | Marbled lancehead | Goiás, Brazil | |
| B. mattogrossensis | 0 | Mato Grosso lancehead | Brazil, Bolivia, Argentina, Peru | |
| B. medusa | 0 | Venezuelan forest-pitviper | Venezuela, including the Cordillera de la Costa (coastal range), the Federal District and the states of Aragua, Bolívar and Carabobo. | |
| B. monsignifer | 0 | Eastern slopes of the Andes of Bolivia and southern Peru | ||
| B. moojeni | 0 | Brazilian lancehead | Central and southeastern Brazil, eastern Paraguay, northeastern Argentina (Misiones) and likely eastern Bolivia | |
| B. muriciensis | 0 | Mata de Murici, Alagoas state, Northeastern Brazil | ||
| B. neuwiedi | 6 | Neuwied's lancehead | South America east of the Andes and south of 5°S, including Brazil (southern Maranhão, Piauí, Ceará, Bahia, Goiás, Mato Grosso, an isolated population in Amazonas, Rondônia and all southern states), Bolivia, Paraguay, Argentina (Catamarca, Córdoba, Corrientes, Chaco, Entre Ríos, Formosa, Jujuy, La Pampa, La Rioja, Mendoza, Misiones, Salta, San Juan, San Luis, Santa Fe, Santiago del Estero and Tucumán) and Uruguay | |
| B. oligobalius | 0 | Amazonian forests of southern Colombia, southern Venezuela, Guyana, Suriname, French Guiana and Brazil north of the Amazon/Solimões | ||
| B. oligolepis | 0 | Peruvian forest-pitviper | Eastern slopes of the Andes in Peru and Bolivia. | |
| B. osbornei | 0 | Western Ecuador, Northwestern Peru | ||
| B. otavioi | 0 | Vitória Island, São Paulo, Brazil | ||
| B. pauloensis | 0 | Brazil, Paraguay, Bolivia | ||
| B. pictus | 0 | Desert lancehead | Peru on the hills of the Pacific coastal region and versant up to about 1800 m elevation | |
| B. pirajai | 0 | Piraja's lancehead | Brazil in central and southern Bahia state and possibly also Minas Gerais | |
| B. pubescens | 0 | Brazil, Uruguay | ||
| B. pulcher | 0 | Andean forest-pitviper | Eastern slopes of the Andes from south-central Colombia to southern Ecuador. | |
| B. punctatus | 0 | Chocoan lancehead | From the Darién of Panama along the Pacific slope of Colombia and Ecuador. | |
| B. sanctaecrucis | 0 | Bolivian lancehead | Bolivia in the Amazonian lowlands from the departments of El Beni to Santa Cruz | |
| B. sazimai | 0 | Franceses Island lancehead | Ilha dos Franceses, Espírito Santo, Brazil | |
| B. sonene | 0 | Madre de Dios, Peru | ||
| B. taeniatus | 1 | Speckled forest-pitviper | Widespread in the equatorial forests of Ecuador, Colombia, Venezuela, Guyana, Suriname, French Guiana, Brazil, Peru and Bolivia. | |
| B. venezuelensis | 0 | Venezuelan lancehead | Northern and central Venezuela, including the Cordillera de la Costa (coast range) and the states of Aragua, Carabobo, the Federal District, Miranda, Mérida, Trujillo, Lara, Falcón, Yaracuy and Sucre, and Colombia (Norte de Santander and Boyacá departments | |