Common names: common lancehead, fer-de-lance, barba amarilla.

Bothrops atrox is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 found in the tropical lowlands of northern South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 east of the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

. No subspecies are currently recognized.

Description

A terrestrial species, adults usually grow to a total length 75–125 cm (about 30-50 inches) and are moderately heavy-bodied. Reports of the maximum size are not clear, as this species is often confused with B. asper

Bothrops asper

Bothrops asper is a venomous pit viper species ranging from southern Mexico to northern South America. Sometimes referred to as the "ultimate pit viper," these snakes are found in a wide range of lowland habitats, often near human habitations. This species is the main cause of snakebite incidents...

. Soini (1974) mentioned that of a series of 80 specimens collected in northeastern Peru, the largest was a female of 138.8 cm (4 ft 6⅝ in). The largest specimen measured by Campbell and Lamar (2004) was a female with a total length of 162 cm (5 ft 3¾ in).

The scalation includes 23-29 (usually 23-25) rows of dorsal scales

Dorsal scales

In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales.When counting dorsal scales, numbers are often given for three points along the body, for example 19:21:17...

 at midbody, 169-214/177-214 ventral scales

Ventral scales

In snakes, the ventral scales 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 contacts the paraventral row of dorsal scales on either side...

 in males/females, 52-86 (usually 75 or fewer) subcaudal scales

Subcaudal scales

In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. These scales may be either single or divided and are preceded by the anal scale....

 in males, which are usually divided, and 47-72 subcaudals in females. On the head the rostral scale is about as high, or slightly higher, than it is wide. There are 3-11 (usually 5-9) keeled

Keeled scales

Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch...

 intersupraocular scales, 7-13 (usually 8-11) sublabial scales

Sublabial scales

In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scale . The term labial originates from Labium , which refers to any lip-like structure...

 and 6-9 (usually 7) supralabial scales

Supralabial scales

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 scale . The term labial originates from Labium , which refers to any lip-like structure...

, the second of which is fused with the prelacunal to form a lacunolabial.

The color pattern is highly variable, including a ground color that may be olive, brown, tan, gray, yellow, or (rarely) rusty. The body markings are highly variable, as is the degree of contrast: in some specimens the pattern is very well defined, while in others it may be virtually absent. In general, however, the body pattern consists of a series of dorsolateral blotches that are rectangular or trapezoidal in shape and extend from the first scale row to the middle of the back. These blotches may oppose or alternate across the midline, often fusing to form bands. They also have pale borders, which in some cases may be prominent, and may be invaded from below by tan or gray pigment, occasionally dividing them into pairs of ventrolateral spots. The belly may be white, cream or yellowish gray, with an increasing amount of gray to black mottling posteriorly that may fade again under the tail. The head usually does not have any markings other than a moderately wide postocular stripe that runs from behind the eye back to the angle of the mouth. The iris is gold or bronze, with varying amount of black reticulation, while the tongue is black.

Common names

Common lancehead, fer-de-lance, barba amarilla.

The Spanish

Spanish language

Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

 common name barba amarilla (yellow beard), an allusion to the pale yellow chin color, is also used in English

English language

English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

. In Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

 it is called labaria or labarria. In Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

 it is called aroani (Yagua), cascabel (juveniles), ihdóni (Bora), jergón, jergona, jergón de la selva, macánchi (Alto Marañón), machacú, marashar and nashipkit (Aguaruna names). In Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

 it is called mapanare. In Colombia

Colombia

Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

 it is known as mapaná (Llanos of Vichada) and taya equis, in Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

 as jergón. The latter is an allusion to the x-like markings of the color pattern. In Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

 these x-like markings have led to the snake simply being referred to as equis (the Spanish pronunciation of the letter 'x'). In Trinidad

Trinidad

Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...

 it is known as mapepire balsain.

Geographic range

Found in the tropical lowlands of South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 east of the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

, including southeastern Colombia

Colombia

Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

, southern and eastern Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

, Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

, Suriname

Suriname

Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...

, French Guiana

French Guiana

French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...

, eastern Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

, eastern Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

, northern Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

 and the northern half of Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. The type locality is listed as "Asia", which is obviously a mistake. Schmidt and Walker (1943:295) proposed that this be corrected to "Surinam."

Habitat

Despite the vast destruction of rain forests, it is amongst the most numerous of pit vipers

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 and is not endangered. In Trinidad it prefers wet lowland forests.

Behavior

Although generally terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

, it is also an excellent swimmer and even climbs trees when necessary to reach prey. Generally nocturnal, but may forage at any time of the day if necessary. These snakes are also easily agitated.

Feeding

The main diet includes most small mammals and birds, but also frogs and lizards. Larger prey is struck and released, after which it is tracked down via its scent trail.

Reproduction

Breeds year-round. After mating, females with developing embryos travel in and out of sunlight to keep them at a constant temperature. In equator

Equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

ial regions, the gestation period is approximately 3–4 months, with an average of 60 young per litter. At birth the young are about 30 cm in length, more brightly colored than adults, and have yellow

Yellow

Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...

 or beige

Beige

Beige may be described as an off tan color or an extremely pale brown color.The term originates from beige cloth, a cotton fabric left undyed in its natural color...

 tails.

Venom

These snakes are known to search for rodents in coffee

Coffea

Coffea is a genus of flowering plants in the Rubiaceae family. They are shrubs or small trees native to tropical and southern Africa and tropical Asia. Seeds of several species are the source of the popular beverage coffee. Coffee ranks as one of the world's most valuable and widely traded...

 and banana

Banana

Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....

 plantations. Workers there are often bitten by the snakes, which can lie camouflaged for hours, nearly undetectable, and strike with high speed.

Their venom consists mostly of Hemotoxin

Hemotoxin

Hemotoxins, haemotoxins or hematotoxins are toxins that destroy red blood cells , disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term hemotoxin is to some degree a misnomer since toxins that damage the blood also damage other tissues...

. Presently, treatment is usually possible if the victim receives medical attention soon enough. Venom yield averages 124 mg, although it may be as much as 342 mg.
The enzyme, reptilase (batroxobin), derived from this snake's venom is used in modern medical laboratories to measure fibrinogen levels and to measure blood coagulation capability. The test is considered to be a replacement for Thrombin Time, and is used when heparin is present in the sample. The enzyme is unaffected by heparin.

Taxonomy

The taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 of this species is controversial; it may include B. leucurus

Bothrops leucurus

Bothrops leucurus is a venomous pitviper species endemic to Brazil. No subspecies are currently recognized.-Geographic range:Found in eastern Brazil along the Atlantic coast from northern Espirito Santo north to Alagoas and Ceara. Occurs more inland in several parts of Bahia. The identity of...

 the B. moojeni

Bothrops moojeni

Bothrops moojeni, or the Brazilian lancehead, is a species of snake in the Viperidae family. It is endemic to Brazil, Paraguay, and Argentina....

, and some of its populations are sometimes said to be separate species. B. asper

Bothrops asper

Bothrops asper is a venomous pit viper species ranging from southern Mexico to northern South America. Sometimes referred to as the "ultimate pit viper," these snakes are found in a wide range of lowland habitats, often near human habitations. This species is the main cause of snakebite incidents...

 was formerly included in this species, but most authorities now consider it distinct.

External links

• Animal Diversity Web page on the common lancehead
• Page on the common lancehead in Manaus
  Manaus
  Manaus is a city in Brazil, the capital of the state of Amazonas. It is situated at the confluence of the Negro and Solimões rivers. It is the most populous city of Amazonas, according to the statistics of Brazilian Institute of Geography and Statistics, and is a popular ecotourist destination....
  
  , Brazil, with links to photographs (in Portuguese
  Portuguese language
  Portuguese is a Romance language that arose in the medieval Kingdom of Galicia, nowadays Galicia and Northern Portugal. The southern part of the Kingdom of Galicia became independent as the County of Portugal in 1095...
  
  ).. Accessed 14 January 2007.. Accessed 5 December 2007.