Hydrophis belcheri
| Hydrophis belcheri | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Subphylum: | Vertebrata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Elapidae |
| Genus: | Hydrophis |
| Species: | H. belcheri |
| Binomial name | |
| Hydrophis belcheri (Gray, 1849) | |
| Synonyms | |
Hydrophis belcheri, commonly known as the faint-banded sea snake or Belcher's sea snake, is a venomous species of elapid sea snake. It has a timid temperament and would normally have to be subjected to severe mistreatment before biting. Usually those bitten are fishermen handling nets, although only a quarter of those bitten are envenomated since the snake rarely injects much of its venom. Because of this, and its docile nature, it is generally not regarded as very dangerous. Although not much is known about the venom of this species,[2] its LD50 toxicity in mice has been determined to be 0.24 mg/kg[3] when delivered intramuscularly.
Belcher's sea snake, which many times is mistakenly called the hook-nosed sea snake (Enhydrina schistosa), has been erroneously popularized as the most venomous snake in the world, due to Ernst and Zug's published book "Snakes in Question: The Smithsonian Answer Book" from 1996. Associate Professor Bryan Grieg Fry, a prominent venom expert, has clarified the error: "The hook nosed myth was due to a fundamental error in a book called 'Snakes in question'. In there, all the toxicity testing results were lumped in together, regardless of the mode of testing (e.g. subcutaneous vs. intramuscular vs intravenous vs intraperitoneal). As the mode can influence the relative number, venoms can only be compared within a mode. Otherwise, its apples and rocks.".[4] Studies on mice[5][6][7] and human cardiac cell culture[4][8][9] shows that venom of the inland taipan, drop by drop, is the most toxic among all snakes; land or sea. The most venomous sea snake is actually Dubois' seasnake (Aipysurus duboisii ).
Description
The belcher's sea snake is of moderate size, ranging from 0.5 to 1 meter (about 20-40 inches) in adult length. Its thin body is usually chrome yellowish in colour with dark greenish crossbands. The dorsal pattern does not extend onto the venter. The head is short and has bands of the same colours. Its mouth is very small but suitable for aquatic life. Its body when viewed out of water appears to have a faint yellow colour. Its scales are different from most other snakes in that they overlap each other. Each dorsal scale has a central tubercle. The body is strongly laterally compressed posteriorly. The ventral scales are very narrow, only slightly wider than the dorsal scales.
Behavior
Like other sea snakes, it has a paddle-like tail which makes it an expert swimmer, and it rarely goes on land. It eats fish and shellfish. It breathes air, and has valves over its nostrils that close underwater. It can hold its breath for as long as 7 to 8 hours while hunting and even sleeping, but then has to surface for a quick breath of air. It is generally docile and not aggressive. It may deliver a provoked bite only after repeated severe treatment. It usually bites fishermen handling nets, but only 25% of those bitten are envenomed.
Distribution
Indian Ocean (Philippines: Visayan area, Panay; New Guinea), Gulf of Thailand, Australia (North Territory?, Queensland?), Solomon Islands [McCoy 2000]. Especially around the Ashmore Reef in the Timor Sea off northwest Australia. Also New Caledonia
Taxonomic history
This species was first described and named by John Edward Gray in 1849.
Etymology
Hydrophis comes from Greek "hydro" = water + "ophis" = serpent.
The specific name, belcheri, commemorates the Nova Scotian, Royal Navy Captain, later Admiral, Sir Edward Belcher KCB, RN (1799-1877) who collected the holotype.
Common names
H. belcheri is also referred to as Belcher's ocean snake. Belcher's sea snake has been mistakenly called the "hook-nosed sea snake" (which is actually Enhydrina schistosa) and in one instance was called the "blue-banded sea snake" (which is actually one common name for Hydrophis cyanocinctus).
References
- ↑ The Reptile Database. www.reptile-database.com.
- ↑ WCH Clinical Toxinology Resources: Hydrophis belcheri
- ↑ Tamiya N, Puffer H (1974). Lethality of sea snake venoms. Toxicon, 12:85-87.
- 1 2 Fry, Bryan (February 08, 2005) Most Venomous,"Q;I was wondering what snakes venom is the most potent to humans A:Drop for drop it is the inland taipan (Oxyuranus microlepidotus), which has a venom more toxic than any other land snake or even the sea snakes." venomdoc.com Forums, Retrieved April 17, 2014
- ↑
- The Australian venom research unit (August 25, 2007). "Which snakes are the most venomous?". University of Melbourne. Retrieved October 14, 2013.
- Venom Immunochemistry, Pharmacology and Emergency Response (VIPER) Institute. Frequently Asked Questions -What is the most venomous snake?. "Many experts answer that it is the Inland Taipan of Australia, because its drop-by-drop concentration of venom has great potency when measured by its ability to kill rodents" . University of Arizona. Retrieved October 14, 2013.
- Department of Wildlife Ecology and Conservation. Frequently Asked Questions About Venomous Snakes. "A comparative study found that the snake venom that is most toxic to mice (of the species tested) is that of the Inland Taipan (Oxyuranus microlepidotus), found in Australia". University of Florida. Retrieved November 5, 2013.
- Hodgson WC, Dal Belo CA, Rowan EG (2007). "The neuromuscular activity of paradoxin: a presynaptic neurotoxin from the venom of the inland taipan (Oxyuranus microlepidotus)". Neuropharmacology 52 (5): 1229–36. doi:10.1016/j.neuropharm.2007.01.002. PMID 17313963.
The inland taipan is the world's most venomous snake
- Bell, Karen L; Sutherland, Struan K; Hodgson, Wayne C (1998). "Some pharmacological studies of venom from the inland taipan (Oxyuranus microlepidotus)". Toxicon 36 (1): 63–74. doi:10.1016/S0041-0101(97)00060-3. PMID 9604283.
The Inland Taipan is believed to have the most toxic venom in the world (Sutherland, 1994)
- Journal of Herpetology Vol.17 no.1 (1983) Ecology of Highly Venoumous Snakes: the Australian Genus Oxyuranus. "..the number of mouse LD50 doses per bite is much higher for Oxyuranus microlepidotus (218,000 mice)...than for any other snakes, including sea snakes, investigated to date (Broad, Sutherland and Coulter, 1979)." (page 1) University of Sydney. Retrieved November 8, 2013.
- ↑
- LISTS . Nine of the World's Deadliest Snakes. "#1: The snake with the world's deadliest venom - Oxyuranus microlepidotus" . Encyclopædia Britannica. Retrieved November 5, 2013.
- BBC Nature Wildlife. Inland Taipan page. "Australia's inland taipan is considered to be the most venomous snake in the world". BBC. Retrieved October 15, 2013.
- Cecilie Beatson (November 29, 2011). ANIMAL SPECIES:Inland Taipan "The venom of the Inland Taipan is extremely potent and is rated as the most toxic of all snake venoms in LD50 tests on mice". Australian Museum. Retrieved October 14, 2013.
- Steve Irwin presentation .Australia Zoo Tour with Steve Irwin (1m54s) "..the number 1 most venomous snake in the entire world, the fierce snake". Australia Zoo (official Youtube Channel). Retrieved October 14, 2013.
- ↑ Inland Taipan Venom vs. Sea Snakes Venom (most notable Belcher's sea snake)
- Oakley, Cecily (2011). Interview with Associate Professor Bryan Fry Biochemist and molecular biologist. "...For my PhD, I worked on the inland taipan, which is the world’s most venomous snake..." . Australian Academy of Science. Retrieved October 14, 2013.
- kingsnake.com September Guest Chatter (September 16, 2006).Q&A with Dr. Bryan Grieg Fry, Deputy Director, Australian Venom Research Unit, University of Melbourne. "Q: In retrospect to the LD50 charts, what do you personally feel is the hottest snake, in regards to potency, defensiveness, means of injection, etc.? A: It is the inland taipan (Oxyuranus microlepidotus). Not, as is popularised, any of the sea snakes." connectedbypets.com. Retrieved October 14, 2013.
- Garden of Eden Exotics (May 2, 2012) Dr. Bryan Grieg Fry – Interview "...The inland taipan (Oxyuranus microlepidotus') is far and away the most toxic, much more so than even sea snakes." nyexotics.blogspot.com Retrieved October 14, 2013
- ↑ Seymour, Jamie, World's Worst Venom, (Min 44.33) "Among the reptiles tested, the most toxic venom belongs to inland taipan, killing over 60% of heart cells in the first 10 minutes" National Geographic Channel Retrieved April 17, 2014
- ↑ Seymour, Jamie Venom deathmatch "They have the most toxic venom towards humans then any other snake in the world" (min 1:49) National Geographic Channel, Retrieved April 17, 2014
Further reading
- Boulenger GA. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ), ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I- XXV. (Distira belcheri, pp. 296-297 + Plate XVII, Figure 2).
- Gray JE. 1849. Catalogue of the Specimens of Snakes in the Collection of the British Museum. London: Trustees of the British Museum. (Edward Newman, printer). xv + 125 pp. (Aturia belcheri, p. 46).
- McCarthy CJ, Warrel DA. 1991. A collection of sea snakes from Thailand with new records of Hydrophis belcheri (Gray). Bull. Br. Mus. Nat. Hist. (Zool.) 57 (2): 161-166.
- McCoy M. 2000. Reptiles of the Solomon Islands. Kuranda, Australia: ZooGraphics. CD-ROM.