Pseudechis australis

Pseudechis australis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Pseudechis
Species: P. australis
Binomial name
Pseudechis australis
(Gray, 1842)[1]
Range of king brown (in red)

Pseudechis australis, commonly known as the king brown- or mulga snake, or Pilbara cobra, is a species of venomous snake found in Australia. It is one of the longest venomous snakes in the world and is the second longest in Australia. Despite one of its common names, "king brown", it is a species in the genus Pseudechis, known as the black snake genus.

Taxonomy

The species was first described by John Edward Gray in 1842, who placed it in the genus Naja (cobras). The species was long regarded as monotypic, but several new taxa have recently been described from within P. australis. Two new species and a new genus have been described within this complex by Raymond Hoser: Pailsus pailsei, from near Mount Isa, Queensland, Australia[2] and Pailsus rossignolii, found in Irian Jaya.[3] Hoser later also resurrected Pailsus weigeli (originally described as Cannia weigeli by Wells and Wellington 1987[4]). These descriptions were initially received with skepticism due to the low level of evidence provided in the original descriptions.[5] Later genetic analyses supported the validity of some of Hoser's species, but his genus Pailsus was shown to be a synonym of Pseudechis, and more work is needed to understand species limits among the smaller species of the group.[6][7][8][9]

Description

Mulga snakes are large, venomous snakes growing up to 2.5 to 3.0 m (8.2 to 9.8 ft) in length in the largest specimens, although 1.5 m (4.9 ft) is a more typical length for an average adult.[10] It is exceeded in length among venomous snakes only by the Asiatic king cobra, some species of African mambas, the Australian taipan, and genus Lachesis (bushmasters) of the American neotropics. A good-sized adult mulga snake of 2 to 2.5 m (6.6 to 8.2 ft) length can weigh 3 to 6 kg (6.6 to 13.2 lb) and mulga snakes are often heavier than the co-occurring taipans.[6][10] The colour of the snakes differs from area to area within their range; mulga snakes can be a light brown colour in the desert to a dark, brown-blackish colour in the cooler regions of Queensland, South Australia and New South Wales. Mulga snakes are robust, with a wide head and smooth snout.

Venom

The mulga snake venom consists of myotoxins. The LD50 is 2.38 mg/kg subcutaneous.[11] Its venom is not particularly toxic to mice, but it is produced in huge quantities. The average tiger snake produces around 10–40 mg when milked. By comparison, a large king brown snake may deliver 150 mg in one bite.

Black snake antivenom is used to treat bites from this species, after a CSL venom detection kit has returned a conclusive result for mulga snake envenomation, and there are signs that antivenom use is required.

Venomous snakes normally only attack humans when disturbed. Mulga snakes have, however, been noted to bite people who were asleep at the time.[12][13]

Distribution and habitat

Mulga snake at the Armadale Reptile Centre

Mulga snakes occur in most states of Australia except for Victoria and Tasmania. Its range includes all of the Northern Territory, most parts of Western Australia, Queensland, New South Wales and South Australia. It may also be found in the western parts of the Australian Capital Territory.

Mulga snakes inhabit woodlands, hummock grasslands, chenopod scrublands and almost bare gibber or sandy deserts, usually sheltering near humans under timber, rubbish piles, burrows and deep soil cracks. They are not found in rainforests.

Reproduction

Female mulga snakes produce a clutch of around 8–20 eggs, which may be laid in a disused burrow or beneath a log or rock. There is no maternal care for the eggs once they have been laid. Eggs take about 2–3 months to hatch, after which time the newly hatched snakes must care for themselves.

Diet

The mulga snake primarily preys on lizards, birds, small mammals and frogs. It is well adapted to eating other snakes, including all venomous snakes.

References

  1. ↑ Gray, J. E. 1842. Description of some hitherto unrecorded species of Australian reptiles and batrachians. Zoological Miscellany, London: Treuttel, Würtz & Co, pp. 51–57.
  2. ↑ Hoser, Raymond (1998). "A new snake from Queensland, Australia (Serpentes: Elapidae)". Monitor 10 (1): 5–9, 31.
  3. ↑ Hoser, Raymond (2000). "A New Species of Snake (Serpentes: Elapidae) from Irian Jaya". Litteratura Serpentium 20 (6): 178–186.
  4. ↑ Wells, R.W. and Wellington, C.R. (1987). "A new species of proteroglyphous snake (Serpentes: Oxyuranidae) from Australia". Australian Herpetologist 503: 1–8.
  5. ↑ Wüster, W.; Bush, B.; Keogh, J.S.; O'Shea, M. and Shine, R. (2001). "Taxonomic contributions in the "amateur" literature: comments on recent descriptions of new genera and species by Raymond Hoser". Litteratura Serpentium 21: 67.
  6. ↑ 6.0 6.1 Kuch, Ulrich; Keogh, J. Scott; Weigel, John; Smith, Laurie A.; Mebs, Dietrich (2005). "Phylogeography of Australia's king brown snake (Pseudechis australis) reveals Pliocene divergence and Pleistocene dispersal of a top predator". Naturwissenschaften 92 (3): 121–7. doi:10.1007/s00114-004-0602-0. PMID 15688185.
  7. ↑ Pseudechis australis at the Reptarium.cz Reptile Database
  8. ↑ Wüster, W., A.J. Dumbrell, C. Hay, C.E. Pook, D.J. Williams & B.G. Fry (2005). "Snakes across the Strait: Trans-Torresian phylogeographic relationships in three genera of Australasian snakes (Serpentes: Elapidae: Acanthophis, Oxyuranus and Pseudechis)". Molecular Phylogenetics and Evolution 34 (1): 1–14. doi:10.1016/j.ympev.2004.08.018. PMID 15579378. superseding; Wüster, W., et al. Phylogeny and classification of Australo-Papuan black snakes and mulga snakes: comments on genus Pailsus Hoser (1998)
  9. ↑ Wüster W, Golay P, Warrell DA (August 1999). "Synopsis of recent developments in venomous snake systematics, No. 3". Toxicon 37 (8): 1123–9. doi:10.1016/S0041-0101(98)00248-7. PMID 10400296.
  10. ↑ 10.0 10.1 Mulga or "King Brown" Snake (Pseudechis australis) | Australian Venom Research Unit. Avru.org. Retrieved on 2012-12-21.
  11. ↑ The Australian venom research unit (August 25, 2007). "Which snakes are the most venomous?". University of Melbourne. Retrieved October 15, 2013.
  12. ↑ "Your Next Nightmare: Venomous Snake Bites People in Their Sleep". LiveScience. April 22, 2014.
  13. ↑ Razavi, S.; Weinstein, S. A.; Bates, D. J.; Alfred, S.; White, J. (2014). "The Australian mulga snake (Pseudechis australis: Elapidae): Report of a large case series of bites and review of current knowledge". Toxicon. doi:10.1016/j.toxicon.2014.04.003.

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