Inland Taipan

Fierce Snake (Inland Taipan)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Elapidae
Genus:	Oxyuranus
Species:	O. microlepidotus
Binomial name
Oxyuranus microlepidotus (McCoy, 1879)
Range of Inland Taipan (in red)

The Inland Taipan (Oxyuranus microlepidotus), also known as the Small Scaled Snake and Fierce Snake, is native to Australia and is regarded as the most venomous land snake in the world based on LD50 values in mice.^[1] It is a species of taipan belonging to the Elapidae family. Although highly venomous, it is very shy and reclusive, and always prefers to escape from trouble (the word "fierce" from its alternate name describes its venom, not its temperament).^[2]

Appearance

The Inland Taipan is dark tan, ranging from a rich, dark hue to a brownish olive-green, depending on season. Its back, sides and tail may be different shades of brown and grey, with many scales having a wide blackish edge. These dark-marked scales occur in diagonal rows so that the marks align to form broken chevrons of variable length that are inclined backward and downward. The lowermost lateral scales often have an anterior yellow edge. The dorsal scales are smooth and without keels. The round-snouted head and neck are usually noticeably darker than the body (glossy black in winter, dark brown in summer), the darker colour allowing the snake to heat itself while only exposing a smaller portion of the body at the burrow entrance. The eye is of average size with a blackish brown iris and without a noticeable coloured rim around the pupil. It has twenty-three rows of mid-body scales, between fifty-five and seventy divided subcaudal scales, and one anal scale. The Inland Taipan averages approximately 1.8 metres (5.9 ft) in length, although larger specimens can reach lengths of 2.5 metres (8.2 ft).^[3]

Seasonal adaptation

Inland taipans adapt to their environment by changing the colour of the skin during seasonal changes. They tend to become lighter during summer and darker during the winter. This seasonal color change serves the purpose of thermoregulation, allowing the snake to absorb more light in the colder months.

Geographical distribution

The inland taipan is native to the arid regions of central Australia. Its range extends from the southeast part of the Northern Territory into west Queensland. The snake can also be found north of Lake Eyre and to the west of the split of the Murray River, Darling River, and Murrumbidgee River.

Behavior

Diet

The Inland Taipan consumes mostly rodents, small mammals and birds. It kills with a single accurate bite, then retreats while waiting for the prey to die before returning to safely consume its meal.

Reproduction

Inland Taipan produce clutches of between one and two dozen eggs. The eggs hatch two months later. The eggs are usually laid in abandoned animal burrows and deep crevices. Reproduction rate depends in part on their diet. If there is not enough food then the snake will reproduce less.

Venom

The Inland Taipan's venom consists of Taipoxin and protease enzymes, the average quantity of venom delivered by this species is 44 mg and the maximum dose recorded is 110 mg. The median lethal dose (LD₅₀) for mice is 2 μg/kg (ppb) for pure Taipoxin^[4] and 30 μg/kg (ppb) for the natural venom mixture.^[5] Its venom consists mostly of neurotoxins. As of late 2003, all positively identified inland taipan bite victims have been herpetologists handling the snakes for study, and all have been treated successfully with antivenom—no incidents have been fatal.^[6][7]

Gallery

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  Brown coloured (winter)

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  Olive coloured (summer)

References

1. ^ LD50 Values for snake venom, 1999
2. ^ "Our Animals – Reptiles – Venomous Snakes – Fierce Snake". Australia Zoo. http://www.australiazoo.com.au/our-animals/amazing-animals/reptiles/?reptile=venomous_snakes&animal=fierce%20snake. Retrieved 2009-05-21. 
3. ^ "Fierce Snake (Inland Taipan)". Australian Reptile Park. http://www.reptilepark.com.au/animals.asp?catID=16&ID=112. Retrieved 2009-11-07. 
4. ^ J. Fohlman, D. Eaker, E. Karlsoon, S. Thesleff (1976). "Taipoxin, an extremely potent presynaptic neurotoxin from the venom of the australian snake taipan (Oxyuranus s. scutellatus). Isolation, characterization, quaternary structure and pharmacological properties". Eur. J. Biochem.: 457–69. doi:10.1111/j.1432-1033.1976.tb10833.x. PMID 976268. 
5. ^ "Strength of Venom". School of Chemistry, University of Bristol. http://www.chm.bris.ac.uk/webprojects2003/stoneley/strength.htm. Retrieved 2008-02-29. 
6. ^ Barrett, Robyn; Mark Little (Oct–Dec 2003). "Five years of snake envenoming in far north Queensland". Emergency Medicine 15 (5–6): 500–510. doi:10.1046/j.1442-2026.2003.00509.x. PMID 14992068. "There have only been a handful of reports of envenoming by the inland taipan (Oxyuranus microlepidotus). As in our patient, they have only occurred in herpetologists." 
7. ^ White, Julian (November 1991). "Oxyuranus microlepidotus". Chemical Safety Information from Intergovernmental Organizations. http://www.inchem.org/documents/pims/animal/taipan.htm. Retrieved 24 July 2009. 

External links

Media related to Oxyuranus microlepidotus at Wikimedia Commons

• Australian Reptile Park, Fierce Snake Fact File
• Australia Zoo Fierce Snake Fact File