Taipan

from Wikipedia, the free encyclopedia
Taipan
Coastal Taipan.jpg

Taipan ( Oxyuranus scutellatus )

Systematics
Subordination : Snakes (serpentes)
Superfamily : Adder-like and viper-like (Colubroidea)
Family : Poison Snakes (Elapidae)
Subfamily : Hydrophiinae
Genre : Taipane ( Oxyuranus )
Type : Taipan
Scientific name
Oxyuranus scutellatus
( Peters , 1867)

The Taipan ( Oxyuranus scutellatus ), also known as the Eastern Taipan or Coastal Taipan , is a species of snake belonging to the poisonous snake family . With two other species it forms the genus of the Taipane . Its distribution area includes the rain-rich coastal forests of Australia and Papua New Guinea .

description

anatomy

The Taipan is the largest poisonous snake in Australia. The head-torso length of adult individuals from Australia is 78-226 cm in males, 101-193 cm in females, the tail reaches 19-20% of the head-torso length. The animals are slender, the head is large, rectangular and clearly set off from the relatively slender neck. The canthus is sharp-edged. The sexes do not differ in terms of size and color.

Scaling

Like all venomous snakes, the taipan has nine large, symmetrical shields on the top of its head. The prefrontalia are very large. The frontal has straight sides and is about two and a half times as long as it is wide. The nasal is undivided. The animals have two primary and two or three secondary temporalia ; subocularia are absent. You have six supralabials and seven infralabials . The dorsal scales are smooth or slightly keeled. The animals have 21–23 dorsal rows of scales in the middle of the body. The number of ventral scales ( ventral shields ) varies between 220 and 250, the number of divided subcaudalia between 45 and 80. The anal shield is undivided.

coloring

The basic color of the top is variable light brown, dark brown, red brown, copper red or olive. Animals of the nominate form show no drawing on this basic color. The head is clearly lightened. The underside is whitish.

distribution and habitat

Habitat of the taipan

The range of the taipan includes coastal regions from eastern to northern Australia and southern Papua New Guinea. The species inhabits tropical savannahs and forests there with annual rainfall over 800 mm.

Systematics

In addition to the nominate form, another subspecies is recognized:

  • Oxyuranus s. scutellatus ; Australia
  • Oxyuranus s. canni ; Papua New Guinea; Keeled scales on top in front area; usually with a diffuse orange or pink longitudinal stripe in the middle of the back, which is created by appropriately colored areas of skin between the scales.

Lifestyle and diet

The Taipan is predominantly diurnal and ground dwelling. The animals, like all species of the genus, feed exclusively on animals of the same temperature . Stomach examinations have so far shown almost exclusively mammals as prey, only a bird once. The range of mammals captured is very broad and includes both small marsupials and rodents up to the size of rats. Even young individuals apparently only eat animals of the same temperature; reptiles and amphibians were ignored in captivity. The prey is actively sought, the Taipan uses its sense of smell and the apparently well-developed sense of sight. The prey is bitten at lightning speed and released again immediately. Together with the extremely effective poison, this applies as an adaptation to the prey that is sometimes very defensive (rat species with sharp incisors), which could otherwise endanger the snake. The prey is consumed when it is dead or immobile.

Reproduction

The Taipan is egg laying . Females with eggs in their bodies were found from August to November, and eggs were laid from September to March. According to field and housing observations, the clutches comprise 7 to 17 eggs. In captivity, the juvenile snakes hatch after 64–69 days, when they hatch they have head-trunk lengths of 30–33 cm.

Behavior towards people

The Taipan is very shy and avoids people at an early stage due to his very good sense of sight. The animals only bite when they suddenly feel confronted or cornered. In these cases the animals fight back vehemently and often bite repeatedly.

Poison

effect

The poison taipoxin consists of several components, mainly one or more nerve toxins , and one or more agents that inhibit blood clotting . The neurotoxin blocking presynaptic the signal transfer on the muscles, thus causing paralysis . The average amount of poison per bite is given as 120 mg dry weight. The poison of taipan is extremely effective; the LD 50 value in mice is 0.064 mg / kg.

Due to the large amount of poison and the high toxicity, the bite is usually fatal in humans if left untreated. The bite is often not noticed and local symptoms in the area of ​​the bite site are often absent. Typical symptoms of a bite are initially nausea and vomiting, then progressive paralysis of the muscles up to fatal respiratory failure without treatment and blood clotting disorders. A 4-year-old child apparently bitten several times by a taipan died about an hour after the bites. A 39-year-old man ceased to breathe about 7-10 hours after the bite. The man was given artificial respiration for 19 days and was discharged after 27 days.

Epidemiology

Despite its high toxicity, the Taipan is described as hardly relevant from a medical point of view due to its shyness, and bite accidents occur very rarely.

swell

Individual evidence

  1. ^ MT O'Shea: The Highly and Potentially Dangerous Elapids of Papua New Guinea. In: P. Gopalakrishnakone, LM Chou (Ed.): Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 585-640.
  2. ^ R. Shine, J. Covacevich: Ecology of Highly Venomous Snakes: the Australian Genus Oxyuranus (Elapidae). In: Journal of Herpetology 17, Issue 1, 1983, p. 63.
  3. Fohlman, Jan, David Eaker, Evert Karlsson, Stephen Thesleff: Taipoxin, an extremely potent presynaptic neurotoxin from the venom of the Australian snake taipan (Oxyuranus s. Scutellatus). In: The FEBS Journal , 68, No. 2, 1976, pp. 457-469, PDF
  4. JB Harris, CA Maltin: Myotoxic activity of the crude venom and the principal neurotoxin, taipoxin, of the Australian taipan, Oxyuranus scutellatus. In: British Journal of Pharmacology , 76, No. 1, 1982, pp. 61-75, PDF .
  5. ^ Whyte G. Owen, Craig M. Jackson, Activation of prothrombin with Oxyuranus scutellatus scutellatus (Taipan snake) venom. In: Thrombosis Research , 3, No. 6, 1973, pp. 705-714, doi : 10.1016 / 0049-3848 (73) 90017-0 .
  6. PJ Mirtschin, GR Crowe, R. Davis: Dangerous snakes Of Australia. In: P. Gopalakrishnakone, LM Chou (Ed.): Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 80-81 and 89.
  7. PJ Mirtschin, GR Crowe, R. Davis: Dangerous snakes Of Australia. In: P. Gopalakrishnakone, LM Chou (Ed.): Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 83-85.
  8. ^ PJ Mirtschin, GR Crowe, R. Davis: Dangerous Snakes Of Australia. In: P. Gopalakrishnakone, LM Chou (Ed.): Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 90-91.

literature

  • PJ Mirtschin, GR Crowe, R. Davis: Dangerous snakes Of Australia. In: P. Gopalakrishnakone, LM Chou (Ed.): Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 1-174, ISBN 9971-62-217-3 .
  • R. Shine, J. Covacevich: Ecology of highly venomous snakes: the Australian genus Oxyuranus (Elapidae). In: Journal of Herpetology , 17, Issue 1, 1983, pp. 60-69.
  • GM Storr, LA Smith, RE Johnstone: Snakes of Western Australia . Perth 1986, pp. 86-87, ISBN 0-7309-0399-0 .

Web links

Commons : Taipane  - collection of images, videos and audio files