Calloselasma is a monotypic genus[3] created for a venomous pit viper species, Calloselasma 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]
| Calloselasma | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Viperidae |
| Subfamily: | Crotalinae |
| Genus: | Calloselasma Cope, 1860 |
| Species: | C. rhodostoma
|
| Binomial name | |
| Calloselasma rhodostoma (Kuhl, 1824)
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| Synonyms | |
| |
- Common names: Malayan ground pit viper, Malayan pit viper, Malayan ground snake, Malayan moccasin.
Description edit
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 edit
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 edit
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 edit
This species is oviparous and the eggs are guarded by the female after deposition.[7]
Venom edit
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 edit
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 edit
- ^ 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 19 November 2021.
- ^ 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).
- ^ "Calloselasma". Integrated Taxonomic Information System. Retrieved 3 November 2006.
- ^ "Calloselasma rhodostoma". Integrated Taxonomic Information System. Retrieved 3 November 2006.
- ^ a b Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
- ^ 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.)
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Guangmei Yan, Jiashu Chen, Pengxin Qiu, Hong Shan. "Fibrinolysin of Agkistrodon acutus Venom and its Usage."
Further reading edit
- Kuhl, H. 1824. Sur les Reptiles de Java. Bull Sci. nat. Géol. 2: 79-83. (Trigonocephalus rhodostoma)
- Warrell DA, Looareesuwan S, Theakston RD, et al. (November 1986). "Randomized comparative trial of three monospecific antivenoms for bites by the Malayan pit viper (Calloselasma rhodostoma) in southern Thailand: clinical and laboratory correlations". The American Journal of Tropical Medicine and Hygiene. 35 (6): 1235–47. doi:10.4269/ajtmh.1986.35.1235. PMID 3538922.
- Ho M, Warrell DA, Looareesuwan S, et al. (May 1986). "Clinical significance of venom antigen levels in patients envenomed by the Malayan pit viper (Calloselasma rhodostoma)". The American Journal of Tropical Medicine and Hygiene. 35 (3): 579–87. doi:10.4269/ajtmh.1986.35.579. PMID 3706625.
- Au LC, Lin SB, Chou JS, Teh GW, Chang KJ, Shih CM (September 1993). "Molecular cloning and sequence analysis of the cDNA for ancrod, a thrombin-like enzyme from the venom of Calloselasma rhodostoma". The Biochemical Journal. 294 (2): 387–90. doi:10.1042/bj2940387. PMC 1134466. PMID 8373353.
- Ponnudurai, G.; Chung, M.C.M.; Tan, N.H. (1994). "Purification and Properties of the L-Amino Acid Oxidase from Malayan Pit Viper (Calloselasma rhodostoma) Venom". Archives of Biochemistry and Biophysics. 313 (2): 373–378. doi:10.1006/abbi.1994.1401. ISSN 0003-9861. PMID 8080286.
- Yingprasertchai, Senee; Bunyasrisawat, Srisurat; Ratanabanangkoon, Kavi (2003). "Hyaluronidase inhibitors (sodium cromoglycate and sodium auro-thiomalate) reduce the local tissue damage and prolong the survival time of mice injected with Naja kaouthia and Calloselasma rhodostoma venoms". Toxicon. 42 (6): 635–646. doi:10.1016/j.toxicon.2003.09.001. ISSN 0041-0101. PMID 14602119.
- Ouyang, Chaoho; Yeh, Horng-I; Huang, Tur-Fu (1986). "Purification and characterization of a platelet aggregation inducer from Calloselasma rhodostoma (Malayan pit viper) snake venom". Toxicon. 24 (7): 633–643. doi:10.1016/0041-0101(86)90026-7. ISSN 0041-0101. PMID 3775783.
- Daltry, Jennifer C.; Ross, Toby; Thorpe, Roger S.; Wuster, Wolfgang (1998). "Evidence that humidity influences snake activity patterns: a field study of the Malayan pit viper Calloselasma rhodostoma". Ecography. 21 (1): 25–34. doi:10.1111/j.1600-0587.1998.tb00391.x. ISSN 0906-7590.
External links edit
- Calloselasma at the Reptarium.cz Reptile Database. Accessed 9 August 2007.
- C. rhodostoma at Thailand Snakes. Accessed 21 Dec 2014.