Brief Summary

provided by EOL authors

Malayan Pitvipers (Calloselasma rhodostoma, formerly Angkistrodon rhodostoma) are dangerous and abundant snakes in Southeast Asia. They are known from Thailand, Cambodia, Java, Peninsular Malaysia, Myanmar, Sumatra, and Vietnam. Snakes in the subfamily Crotalinae, including C. rhodostoma, account for the majority of reported snakebites in Thailand and C. rhodostoma is the leading cause of venomous snakebite across much of Southeast Asia.Its venom can cause severe tissue damage in surviving human snakebite victims.Nualnong et al. (2005) reported on the occurrence, symptoms, and treatment of C. rhodostoma in Thailand. (Nualnong et al. 2005 and references therein)

Calloselasma rhodostomaa is a small (usually <1 m total length) crotaline snake which inhabits lowland forests, scrubland, plantations, and gardens in southern Vietnam, Laos, Cambodia, Thailand, west
Malaysia and Java. It typically lies coiled and motionless on the ground, relying upon crypsis to avoid detection by predators and to ambush prey. Calloselasma rhodostoma is nocturnal and
tropical. Daltry et al. (1998a) found that local ambient relative humidity was highly correlated with activity level. (Daltry et al. 1998a and references therein)

Daltry et al. (1996) reported that geographic variation in Calloselasma rhodostoma venom composition is closely associated with variation in diet and suggested that venom variation is the resolt of geographic variation in selection for feeding on local prey species. Daltry et al. (1998b) documented extensive geographic variation in diet, as well as variation related to sex and reproductive status.

York (1984) reported on male-male ritual combat in Calloselasma rhodostoma, apparently the first known example in an Old World pitviper.

References

  • Chanhome, L., M.J. Cox, et al. 1998. Venomous snakebite in Thailand. I: Medically important snakes. Military Medicine 163(5): 310-317.
  • Daltry, J.C., W. Wüster, and R.S. Thorpe. 1996. Diet and snake venom evolution. Nature 379: 537-540.
  • Daltry, J.C., T. Ross, R.S. Thorpe, and W. Wüster. 1998a. Evidence That Humidity Influences Snake Activity Patterns: A Field Study of the Malayan Pit Viper Calloselasma rhodostoma. Ecography 1: 25-34.
  • Daltry, J.C., W. Wüster, and R.S. Thorpe. 1998b. Intraspecific Variation in the Feeding Ecology of the Crotaline Snake Calloselasma rhodostoma in Southeast Asia.. Journal of Herpetology 32(2): 198-205.
  • Wongtongkam, N., H. Wilde, et al. 2005. A Study of 225 Malayan Pit Viper Bites in Thailand. Military Medicine 170(4): 342-348.
  • York, D.S. The Combat Ritual of the Malayan Pit Viper (Calloselasma rhodostoma). Copeia 1984(3): 770-772.

license
cc-by-3.0
copyright
Leo Shapiro
original
visit source
partner site
EOL authors

Distribution

provided by ReptileDB
Continent: Asia
Distribution: S Vietnam, Cambodia, Thailand, Laos, W Malaysia, Indonesia (Java) annamensis: SE Cambodia, Vietnam
Type locality: Java
license
cc-by-nc-sa-3.0
copyright
Peter Uetz
original
visit source
partner site
ReptileDB

Calloselasma rhodostoma

provided by wikipedia EN

Common names: Malayan ground pit viper, Malayan pit viper, Malayan ground snake, Malayan moccasin.

Calloselasma is a monotypic genus[3] created for a venomous pit viper species, C. rhodostoma, which is endemic to Southeast Asia from Thailand to northern Malaysia and on the island of Java.[2] No subspecies are currently recognized.[4]

Description

 src=
From Karawang, West Java
 src=
Underside of its body

Attains an average total length of 76 cm (30 in), with females being slightly longer than males. Occasionally, they may grow as long as 91 cm (36 in).[5]

A specimen with a total length of 81 cm (32 in) has a tail 9 cm (3.5 in) long.

Dorsally it is reddish, grayish, or pale brown, with two series of large, dark brown, black-edged triangular blotches, which are alternating or opposite. There is also a thin dark brown vertebral stripe, which may be interrupted or indistinct in some specimens. The upper labials are pink or yellowish, and powdered with brown. There is a broad, dark brown, black-edged diagonal stripe from the eye to the corner of the mouth, with a narrower light-colored stripe above it. Ventrally it is yellowish, uniform or powdered or spotted with grayish brown.

The smooth dorsal scales are arranged in 21 rows at midbody. Ventrals 138-157; anal plate entire; subcaudals 34-54 pairs.

Snout pointed and upturned. Rostral as deep as broad. Two internasals and two prefrontals. Frontal as long as or slightly longer than its distance from tip of snout, as long as or slightly shorter than the parietals. 7-9 upper labials. Loreal pit not in contact with the upper labials.[6]

This is the only Asian pit viper with large crown scales and smooth dorsal scales.[7]

Geographic range

Found in Nepal, Thailand, Cambodia, Laos, Vietnam, northern West Malaysia and on the Indonesian island of Java. The type locality is listed as "Java".[2] There are unconfirmed, but credible reports from southern Myanmar (Burma), northern Sumatra and northern Borneo.

Habitat and diet

Prefers coastal forests, bamboo thickets, unused and overgrown farmland, orchards, plantations as well as forests around plantations,[5] where it searches for rats and mice.

Reproduction

This species is oviparous and the eggs are guarded by the female after deposition.[7]

Venom

This species has a reputation for being bad-tempered and quick to strike. In northern Malaysia it is responsible for some 700 incidents of snakebite annually with a mortality rate of about 2 percent. Remarkably sedentary, it has often been found in the same spot several hours after an incident involving humans.[7] Its venom causes severe pain and local swelling and sometimes tissue necrosis, but deaths are not common. Many victims are left with dysfunctional or amputated limbs due to the lack of antivenom and early treatment. In a 2005 study of 225 Malayan pit viper (Calloselasma rhodostoma) bites in Thailand, most victims had mild to moderate symptoms, but 27 of 145 patients (18.6%) developed permanently swollen limbs.[8] There were only two deaths (related to intracerebral hemorrhage) and no amputations. The antivenin manufactured in Thailand seemed effective in reversing the blood clotting caused by the venom. Most patients remained stable and did not require antivenin. The authors suggested that victims not use traditional healers and avoid overuse of tourniquets. In a prospective phase of the study, bites occurred throughout the year but mostly early in the monsoon season (May and June).

Venom and thrombosis treatment

The venom of this species is used to isolate a thrombin-like enzyme called ancrod.[9] This enzyme is used clinically to break down and dissolve thrombi (blood clots) in patients and lower blood viscosity to help prevent heart attack and stroke.[9][10]

References

  1. ^ Grismer, L.; Chan-Ard, T. (2012). "Calloselasma rhodostoma". IUCN Red List of Threatened Species. 2012: e.T192168A2050205. doi:10.2305/IUCN.UK.2012-1.RLTS.T192168A2050205.en. Retrieved 15 January 2020.
  2. ^ a b c d 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).
  3. ^ "Calloselasma". Integrated Taxonomic Information System. Retrieved 3 November 2006.
  4. ^ "Calloselasma rhodostoma". Integrated Taxonomic Information System. Retrieved 3 November 2006.
  5. ^ a b Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
  6. ^ Boulenger, G.A. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the...Viperidæ... Trustees of the British Museum (Natural History). London. xiv + 727 pp. + Plates I.-XXV. (Ancistrodon rhodostoma, pp. 527-528.)
  7. ^ a b c U.S. Navy. 1991. Poisonous Snakes of the World. US Govt. New York: Dover Publications Inc. 203 pp. ISBN 0-486-26629-X.
  8. ^ Wongtongkam, Nualnong; Wilde, Henry; Sitthi-Amorn, Chitr; Ratanabanangkoon, Kavi (April 2005). "A Study of 225 Malayan Pit Viper Bites in Thailand". Military Medicine. 170 (4): 342–348. doi:10.7205/MILMED.170.4.342. ISSN 0026-4075. PMID 15916307.
  9. ^ a b Chen JH, Liang XX, Qiu PX, Yan GM (May 2001). "Thrombolysis effect with FIIa from Agkistrodon acutus venom in different thrombosis model". Acta Pharmacologica Sinica. 22 (5): 420–2. PMID 11743889.
  10. ^ Guangmei Yan, Jiashu Chen, Pengxin Qiu, Hong Shan. "Fibrinolysin of Agkistrodon acutus Venom and its Usage."
license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Calloselasma rhodostoma: Brief Summary

provided by wikipedia EN
Common names: Malayan ground pit viper, Malayan pit viper, Malayan ground snake, Malayan moccasin.

Calloselasma is a monotypic genus created for a venomous pit viper species, C. rhodostoma, which is endemic to Southeast Asia from Thailand to northern Malaysia and on the island of Java. No subspecies are currently recognized.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN