Lachesis (genus)

Lachesis
South American bushmaster, L. muta
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Viperidae
Subfamily:	Crotalinae
Genus:	Lachesis Daudin, 1803
Synonyms
Lachesis - Daudin, 1803 Trigonocephalus - Oppel, 1811 Trigalus - Rafinesque, 1815 Cophias - Merrem, 1820[1]

Common names: bushmasters.^[2]

Lachesis is a genus of venomous pitvipers found in remote forested areas of Central and South America. The generic name refers to one of the Three Fates in Greek mythology who determined the length of the thread of life.^[2] Three species are currently recognized.^[3]

Description

Adults vary in length from 2 to 2.5 m (6.5 to 8.25 ft), although some may grow to as much as 3 m (10 ft). The largest known specimen was just under 3.65 m (12 ft), making it the longest venomous snake in the Western Hemisphere. This is also the longest viper, though not the heaviest (it is surpassed by the gaboon viper and the Eastern diamondback rattlesnake). The bushmaster's tail ends with a horny spine which it sometimes vibrates when disturbed in a similar manner to rattlesnakes. This led to some calling it 'the mute rattlesnake'.

Geographic range

Found in Central and South America.^[1] Also found on the island of Trinidad.^[4]

Reproduction

Bushmasters lay eggs: about a dozen in an average clutch. The female reportedly remains with her eggs during incubation and may aggressively defend the nest if approached. The hatchlings average 30 cm in length and are more colorful than the adults. Lachesis is thought to be unique among New World pit vipers in laying eggs rather than giving birth to live young, although some evidence suggests that the species Bothrocophias colombianus found in Colombia may do the same.^[2]

Venom

One of the largest and most dangerous snakes in South America, this snake is capable of multiple- bite strikes and the injection of large amounts of venom. Even the bite of a juvenile specimen can be fatal.

Species

Species[3]	Taxon author[3]	Subsp.*[3]	Common name[2]	Geographic range[1]
L. melanocephala	Solórzano & Cerdas, 1986	0	Black-headed bushmaster	Costa Rica: Pacific versant of southeastern Puntarenas province from near sea level to about 1500 m.
L. mutaT	(Linnaeus, 1766)	1	South American bushmaster	South America in the equatorial forests east of the Andes: Colombia, eastern Ecuador, Peru, northern Bolivia, eastern and southern Venezuela, Guyana, Surinam, French Guiana and much of northern Brazil. It also occurs on the island of Trinidad.[4]
L. stenophrys	Cope, 1875	0	Central American bushmaster	Central America in the Atlantic lowlands of southern Nicaragua, Costa Rica and Panama, as well as the Pacific lowlands of central and eastern Panama. In South America it occurs in the Pacific lowlands of Colombia and northwestern Ecuador, the Caribbean coast of northwestern Colombia and inland along the Magdalena and Cauca river valleys.

*) Not including the nominate subspecies.
^T) Type species.

Taxonomy

Campbell and Lamar (2004) also recognize a fourth species, L. acrochorda (García, 1896), referring to it as the Chochoan bushmaster. It is found in western Panama and northwestern Colombia and Ecuador.^[2] Its evolutionary relationships are not certain, but Lachesis acrochorda is thought to be closer to the South American bushmaster L. muta than to the two Central American species L. stenophrys and L. melanocephala.

Cultural depictions

The bushmaster snake is the antagonist in the tenth show of the old time radio show Escape. The show's title was "A Shipment of Mute Fate", and starred Jack Webb and Raymond Lawrence. It was broadcast on 15 October 1947. The story was also adapted for Suspense starring Jack Kelly, broadcast on January 6, 1957. The bushmaster is referenced in the film Romancing the Stone.

See also

• List of crotaline species and subspecies
• Crotalinae by common name
• Crotalinae by taxonomic synonyms
• Snakebite

References

1. ^ ^{a b c} McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
2. ^ ^{a b c d e} Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. 2 volumes. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.
3. ^ ^{a b c d} "Lachesis". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=209555. Retrieved 25 October 2006. 
4. ^ ^{a b} List of Snakes of Trinidad and Tobago at Republic of Trinidad and Tobago Biodiversity Clearing House. Accessed 25 October 2006.

Further reading

• Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
• O'Shea M. 2005. Venomous Snakes of the World. Princeton University Press. 160 pp. ISBN 0-691-12436-1.

External links

• Lachesis at the Reptarium.cz Reptile Database. Accessed 24 August 2007.