Published November 4, 2020. Open access.

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Chocoan Bushmaster (Lachesis acrochorda)

Reptiles of Ecuador | Serpentes | Viperidae | Lachesis acrochorda

English common names: Chocoan Bushmaster.

Spanish common names: Verrugosa de la costa, guascama (Ecuador); mapaná rayo, verrugoso, walkauna (Colombia); verrugosa (Panama).

Recognition: ♂♂ 243 cmMaximum distance from the snout to the tip of the tail. ♀♀ 234.2 cmMaximum distance from the snout to the tip of the tail.. In its area of distribution, the Chocoan Bushmaster (Lachesis acrochorda) can be identified by having the following combination of features: heat-sensing pits between the eyes and nostrils, a snout that is not upturned, an arabesque pattern of 23–31 contrasting dark-brown to black blotches on a light orangish-brown dorsum, and prominent knoblike keels on the dorsal scales that give the snake a “pineapple texture.”1,2 The only other viper in western Ecuador having knoblike keels on the dorsal scales is Bothrocophias campbelli, a snake that can easily be identified based on its upturned snout.3

Variation among individuals of Lachesis acrochorda

Figure 1: Individuals of Lachesis acrochorda from Canandé Reserve, Esmeraldas province, Ecuador (); Mashpi Reserve, Pichincha province, Ecuador (); and Morromico, Chocó department, Colombia (). ad=adult, j=juvenile.

Natural history: RareTotal average number of reported observations per locality less than ten. to extremely rareTotal average number of reported observations per locality less than three.. Lachesis acrochorda is a terrestrial snake that inhabits old-growth to moderately disturbed evergreen lowland and foothill forests (rainforests).4 The species generally requires more pristine and remote habitats than other vipers in the Chocó region.4,5 Chocoan bushmasters have been seen active at night as well as during the daytime.4 They spend most of their time coiled on the forest floor close to vegetation cover, usually along streams, steep banks, or at the entrance of mammal burrows.1,4,6 When not active, snakes of this species hide inside hollow logs.7

Chocoan Bushmasters are ambush predators.1 Their diet includes rodents8 and presumably other small mammals. Individuals of Lachesis acrochorda rely on their camouflage as a primary defense mechanism. Unlike popular belief, these vipers are not aggressive, but calm and sluggish when confronted.1,7 In the presence of a disturbance, most individuals try to flee or emit a low whistle-like sound,1 but others will readily bite if attacked or harassed.

“They say that once the traveler has positioned himself within his (a Chocoan Bushmaster’s) radius of attack, the serpent and the man come face-to-face, resolving the problem of life or death. If the man does not have a gun in his hand, he better resolve to strangle the monster, gripping it with athletic force by the throat, and any companion, maintain his grasp among the spirals of the snake, which will not delay in wrapping itself, such that one is obliged to loosen its coils. Overall this may contain some grain of truth; but also a lot of fantasy and marvel.”

Evaristo García, Colombian physician and researcher, 1896.2

Lachesis acrochorda is a venomous species (LD50 4.9–14 mg/kg)9,10 that is responsible for 0.7–2.9% of snakebites in some areas of its range.11,12 In humans, bites of this species, although infrequent, typically cause pain, nausea, vertigo, low blood pressure, swelling, intense bleeding, defibrination (depletion of the blood’s coagulation factors), and necrosis (death of tissues and cells).10,11,13 In poorly managed or untreated cases, the venom can cause intracranial hemorrhage, shock, renal disturbances, permanent sequelae, and (in 90% of cases that are not properly attended)14 death.15 The prognosis is usually bad for victims that reach a hospital over 12 hours after the bite and for those that resort to traditional medicine.15

What to do if you are bitten by a Chocoan Bushmaster?

  1. Remain calm.
  2. Remove rings and tight fitting clothes to avoid swelling.
  3. Reduce movement of bitten extremity to reduce absorption of venom.
  4. Avoid the application of tourniquets, electric shocks, traditional medicine, venom suction, and incision of the bite wound.
  5. Plan immediate evacuation to a medical facility that has antivenom and avoid any action that may delay transportation.
  6. At the medical facility, personnel can initiate treatment with the appropriate antivenom, monitor vital signs, and perform laboratory tests.

Reproduction in Lachesis acrochorda seems to take place year-round.6 In captivity, one male courted a female for 15 days.5 After a gestation period of 110 days (~3.6 months),5 females lay 5–14 eggs in burrows (of agoutis and armadillos), but they do not provide significant parental care to the clutch.5,6,8 The egg’s incubation period is 70–96 days (~2.3–3 months).5,6 Neonates measure 36.1–47.5 cm.5,6 Under human care, individuals can live up to ~18 years,1 and probably much longer.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances.. Lachesis acrochorda is here proposed to be assigned in this category following IUCN criteria16 because the species is widely distributed throughout the lowlands of the Chocó and Río Magdalena valley regions,2 especially in areas that have not been heavily affected by deforestation, such as the Colombian Pacific coast. As a result, the species is considered to be facing no major immediate extinction threats. Unfortunately, Chocoan Bushmasters suffer from direct killing6 and habitat loss,5 especially in Ecuador, where an estimated17 ~59.7% of the habitat of the species has been destroyed.

Distribution: Lachesis acrochorda is native to the lowlands and adjacent mountain foothills of the Chocó and Río Magdalena valley regions from eastern Panamá, through Colombia, to northwestern Ecuador. In Ecuador, the species occurs at elevations between 3 and 1045 m.

Distribution of Lachesis acrochorda in Ecuador

Figure 2: Distribution of Lachesis acrochorda in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Lachesis is derived from the name of one of the “Three Fates” (also known as Moirae or incarnations of destiny) in Greek mythology.2 Lachesis was the Moira that decided the length of life allotted to each human being and god.2 This epithet was probably given to reflect the feeling of having one’s fate at the mercy of the snake upon encountering such an imposing creature.18 The specific epithet acrochorda, which is derived from the Greek word akrochordon (meaning “wart”), refers to the knoblike keels on the dorsal scales.2

See it in the wild: In Ecuador, Chocoan Bushmasters are recorded rarely, usually no more than once every few months at any given locality. However, there are some areas, like in Mashpi Lodge and Canandé Reserve, where individuals are seen more frequently, albeit certainly not reliably. The snakes may be located by walking along trails or by cruising roads through primary forest.

Acknowledgments: Special thanks to Carlos Robles, Darwin Núñez, David Salazar, Elson Meneses-Pelayo, Konrad Mebert, Pablo Loaiza, and Regdy Vera for providing natural history information and locality records for Lachesis acrochorda.

Special thanks to Nicola Paganuzzi and Nicolas Betancourt for symbolically adopting the Chocoan Bushmaster and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di Doménico.cAffiliation: Keeping Nature, Bogotá, Colombia.

How to cite? Arteaga A (2020) Chocoan Bushmaster (Lachesis acrochorda). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/SDLV8376

Literature cited:

  1. Valencia JH, Garzón-Tello K, Barragán-Paladines ME (2016) Serpientes venenosas del Ecuador: sistemática, taxonomía, historial natural, conservación, envenenamiento y aspectos antropológicos. Fundación Herpetológica Gustavo Orcés, Quito, 653 pp.
  2. Campbell JA, Lamar WW (2004) The venomous reptiles of the western hemisphere. Cornell University Press, Ithaca, 774 pp.
  3. Arteaga A, Bustamante L, Guayasamin JM (2013) The amphibians and reptiles of Mindo. Universidad Tecnológica Indoamérica, Quito, 257 pp.
  4. Field notes, Reptiles of Ecuador book project.
  5. Henao Duque AM, Corrales G (2015) First report of the reproduction in captivity of the Chocoan Bushmaster, Lachesis acrochorda (García, 1896). Herpetology Notes 8: 315–320.
  6. Fuentes RD, Corrales G (2016) New distribution record and reproductive data for the Chocoan Bushmaster, Lachesis acrochorda (Serpentes: Viperidae), in Panama. Mesoamerican Herpetology 3: 115–127.
  7. Konrad Mebert, pers. comm.
  8. Elson Meneses-Pelayo, pers. comm.
  9. Kuch U, Mebs D, Gutiérrez JM, Freire A (1996) Biochemical and biological characterization of the Ecuadorian pitvipers (genera Bothriechis, Bothriopsis, Bothrops, and Lachesis). Toxicon 34: 714–717. DOI: 10.1016/0041-0101(96)00016-5
  10. Otero R, Furtado MFD, Gonçalves LR, Núñez V, García ME, Osorio RG, Romero M, Gutiérrez JM (1998) Comparative study of the venoms of three subspecies of Lachesis muta (bushmaster) from Brazil, Colombia and Costa Rica. Toxicon 36: 2021–2027. DOI: 10.1016/s0041-0101(98)00089-0
  11. Sevilla-Sánchez MJ, Mora-Obando D, Calderón JJ, Guerrero-Vargas JA, Ayerbe-González S (2019) Accidente ofídico en el departamento de Nariño, Colombia: análisis retrospectivo, 2008–2017. Biomédica 39: 715–736. DOI: 10.7705/biomedica.4830
  12. Touzet JM (1998) La endemia ofidiana en Ecuador, estudio de caso: accidentes ofídicos en las provincias de Esmeraldas y Manabí. Fundación Herpetológica Gustavo Orcés, Quito.
  13. Otero R, Osorio RG, Valderrama R, Giraldo CA (1992) Efectos farmacológicos y enzimáticos de los venenos de serpientes de Antioquia y Chocó (Colombia). Toxicon 30: 611–620. DOI: 10.1016/0041-0101(92)90855-Y
  14. Angel-Camilo KL, Guerrero-Vargas JA, Carvalho EF, Lima-Silva K, de Siqueira RJB, Freitas LBN, Sousa JAC, Mota MRL, Santos AAD, Neves-Ferreira A, Havt A, Leal L, Magalhaes PJC (2020) Disorders on cardiovascular parameters in rats and in human blood cells caused by Lachesis acrochorda snake venom. Toxicon 184: 180–191. DOI: 10.1016/j.toxicon.2020.06.009
  15. Otero R, Tobón GS, Gómez LF, Osorio R, Valderrama R, Hoyos D, Urreta JE, Molina S, Arboleda JJ (1992) Accidente ofídico en Antioquia y Chocó. Acta Médica Colombiana 17: 229–249.
  16. IUCN (2001) IUCN Red List categories and criteria: Version 3.1. IUCN Species Survival Commission, Gland and Cambridge, 30 pp.
  17. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  18. Diniz-Sousa R, Moraes JN, Rodrigues-da-Silva TM, Oliveira CS, Caldeira CAS (2020) A brief review on the natural history, venomics and the medical importance of bushmaster (Lachesis) pit viper snakes. Toxicon 7: 1–12. DOI: 10.1016/j.toxcx.2020.100053

Appendix 1: Locality data used to create the distribution map of Lachesis acrochorda in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

ColombiaNariñoCumilinchePhoto by Juan Carvajal
ColombiaNariñoEl PangánPhoto by Juan Carlos Luna
ColombiaNariñoEl VergelSevilla-Sánchez et al. 2019
ColombiaNariñoLaguna El Placer, environs ofSevilla-Sánchez et al. 2019
ColombiaNariñoSomewhere in BarbacoasSevilla-Sánchez et al. 2019
EcuadorCotopaxiEl Jardín de los SueñosPhoto by Christophe Pellet
EcuadorEsmeraldasBilsa Biological ReserveValencia et al. 2016
EcuadorEsmeraldasCachabiUSNM 165008
EcuadorEsmeraldasCentro de Fauna Silvestre James BrownPhoto by Salvador Palacios
EcuadorEsmeraldasComunidad Loma LindaValencia et al. 2016
EcuadorEsmeraldasEl AguacateValencia et al. 2016
EcuadorEsmeraldasGualpíMorales-Mite 2002
EcuadorEsmeraldasGualpí de OnzoleValencia et al. 2018
EcuadorEsmeraldasHacienda EquinoxUSNM 237086
EcuadorEsmeraldaskm 17 Lita–Alto TamboValencia et al. 2016
EcuadorEsmeraldasLa TablaMorales-Mite 2002
EcuadorEsmeraldasLas MareasiNaturalist
EcuadorEsmeraldasLote SalvadoresThis work
EcuadorEsmeraldasMacaráValencia et al. 2016
EcuadorEsmeraldasMajúa, Río CayapasMCZ 11169
EcuadorEsmeraldasMaldonadoValencia et al. 2016
EcuadorEsmeraldasMayronga, LagartoValencia et al. 2016
EcuadorEsmeraldasMuisneValencia et al. 2016
EcuadorEsmeraldasNear Río CayapasiNaturalist
EcuadorEsmeraldasPadre SantoValencia et al. 2016
EcuadorEsmeraldasPajonalValencia et al. 2016
EcuadorEsmeraldasPlaya de OroValencia et al. 2016
EcuadorEsmeraldasPoteMorales-Mite 2002
EcuadorEsmeraldasSalto del BravoValencia et al. 2016
EcuadorEsmeraldasSan Lorenzo–LitaValencia et al. 2016
EcuadorEsmeraldasTangarealValencia et al. 2016
EcuadorEsmeraldasTesoro EscondidoReserva Tesoro Escondido
EcuadorEsmeraldasTundalomaPablo Loaiza, pers. comm.
EcuadorEsmeraldasY de la LagunaÍtalo Tapia, pers. comm.
EcuadorEsmeraldasZapallo GrandeMHNG 2458.046
EcuadorImbaburaFinca Agroecológica Los RoblesDarwin Núñez, pers. comm.
EcuadorImbaburaLitaMHNG 2528.067
EcuadorImbaburaLos CedrosiNaturalist
EcuadorManabíFlavio AlfaroMHNG 2511.097
EcuadorManabíHacienda SiberiaHamilton et al. 2005
EcuadorManabíkm 16 Pedernales–El CarmenDavid Salazar, pers. comm.
EcuadorManabíLower Pata de PájaroCarlos Robles, pers. comm.
EcuadorPichinchaBetween Mashpi and YurimaguaiNaturalist
EcuadorPichinchaEl Chalpi-SaguangalValencia et al. 2016
EcuadorPichinchaMashpi ReserveThis work
EcuadorPichinchaRainforest MonterrealPhoto by Jorge Ambuludi
EcuadorPichinchaRancho SuamoxPhoto by Rafael Ferro
EcuadorPichinchaSelva VirgenThis work
EcuadorPichinchaUnidos VenceremosValencia et al. 2016
EcuadorSanto Domingo de los TsáchilasHacienda El CortejoValencia et al. 2016
EcuadorSanto Domingo de los TsáchilasLa EvelinaPhoto by Salvador Palacios
EcuadorSanto Domingo de los TsáchilasLa PerlaPhoto by Paul Hamilton