Pseudonaja mengdeni

Mengden's brown snake
Common
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Pseudonaja
Species: P. mengdeni
Binomial name
Pseudonaja mengdeni
(Wells & Wellington, 1985)

Pseudonaja mengdeni is commonly known as Mengden's Brown Snake,[1] Western Brown Snake and alternatively, Gwardar[2]

Pseudnaja mengdeni is endemic to Australia. It is highly variable in colour and patterns[1] and is a highly dangerous elapid that can cause severe symptoms resulting in death if bitten.[3] It is one of the three species originally classified as Pseudonaja nuchalis along with P. aspidorhyncha, and P. nuchalis.[2]

Taxonomy

Previously the Mengden’s Brown Snake was considered a ‘morph‘ form of Pseudonaja nuchalis, recent genetic studies have proven it to be genetically unique.[4]

It is estimated that Pseudonaja nuchalis could include in excess of 10 different species.[4] Although currently there have been 8 species chromosomeally identified species these include: P. aspidorhyncha, P. mengdeni, P. imperator, P. acutirostris, P. gowi, P. carinata, P. kellyi and P. nuchalis.[4]

Description

P. mengdeni grows up to a total length of 2m[1] with an average length 1.2m[4] It has slender body and narrow head.[5] Mengden's brown snake is highly variable in colour and patterns, ranging from light brown to almost black.[1] However it has two distinct forms ‘Orange with black head’ or ‘Pale head, grey nape’[2] The underside along the belly is often cream, yellow, orange, or grey in colouration, frequently consisting of dark orange or grey blotches.[1]

Scales on the head often form a black V or W pattern.[5] Mengden’s brown snake can be confused with the Eastern brown snake which has a pink mouth lining,[3] the Western brown snake has a purplish/blue-black mouth lining.[6][7] P. mengdeni has a distinctive large strap-like scale around the front of the snout.[7] To accurately identify this species the scales around the mid-body and along the lips need to be counted. 180-230 ventral scales, 45-70 subcaudals with a divided anal scale and 17 or 19 rows of smooth mid-body scales.[1] However this must only be done by an experienced herpetologist, as a scratch from the fangs can still be fatal from P. mengdeni.[3]

Confusion between the species is largely due to the possible hybridisation between the Pseudonaja species.[2]

Mengden’s brown snake is often confused with other Pseudonaja spp. (brown snakes) and also Aspidites melanocephalus (black headed python).[2]

Distribution and habitat

Found from the coast of Western Australia through central Australia to the north-west of New South Wales and western Queensland. The species distribution is poorly defined within its northern limits[1] however it is absent from wetter areas of eastern Australia and south-western Western Australia.[8]

P. mengdeni is practically found throughout all dry to arid areas including, woodlands, Boree woodlands, sandhill woodlands, mallee woodlands, spinifex deserts, spinifex-covered dunefields, sandplains, stony plains, croplands, grasslands and temperate sclerophyll forests.[1][9] The Western brown snake often found within fallen timber, dead trees, shrubs, native grasses and ground cavities.[3]

A Rocky Landscape, Queensland, Australia
A Spinifex Landscape, Queensland, Australia
A Red Sand Dune, Queensland, Australia

Diet

P. mengdeni preys upon small reptiles, mammals, other snakes, ground nesting birds and eggs.[1]

Reproduction

P. mengdeni is oviparous and can lay up to in excess of 12 eggs per clutch.[4]

Venom

P. mengdeni has highly dangerous venom neurotoxic and haemotoxic[2] and can cause severe symptoms resulting in death.[3] Mengden's Brown Snake is considered dangerously venomous.[9]

Antivenom used in case of envenoming is the Brown Snake Antivenom[10] If bitten first aid must be applied and medical attention sought.

Behaviour

P. mengdeni will rear their fore-body into an S-shape when threatened[9] lifting their head off the ground and open their mouth.[3] Is also a terrestrial species that is diurnal however it can be active on warm nights[3]

References

  1. 1 2 3 4 5 6 7 8 9 Cogger, Harold (2014). Reptiles and Amphibians of Australia (7th ed.). Australia: CSIRO Publishing. p. 926. ISBN 9780643100350.
  2. 1 2 3 4 5 6 Beatson, Cecilie. "Animal Species: Western Brown Snakes (nuchalis-complex)". Australian Museum. Australian Museum. Retrieved 10 October 2014.
  3. 1 2 3 4 5 6 7 Michael, Damian; Lindenmayer, David (2010). Reptiles of the NSW Murray Catchment, A Guide to Their Identification, Ecology, and Conservation. Australia: CSIRO Publishing. pp. 206–207. ISBN 9780643098206.
  4. 1 2 3 4 5 Wells, Richard (2002). "Taxonomy of the genus Pseudonaja (Reptilia: Elapidae) in Australia" (PDF). Australian Biodiversity Record (7): 8. ISSN 1325-2992.
  5. 1 2 Edwards, Belinda (2011). Australian Snakes a Pictorial Guide. Australia: The Five Mile Press Pty Ltd. p. 63. ISBN 9781742116181.
  6. ↑ Swan, Gerry; Shea, Glenn; Sadlier, Ross (2004). A Field Guide to Reptiles of New South Wales (2nd ed.). Australia: Reed New Holland. p. 256. ISBN 187706906X.
  7. 1 2 Swan, Gerry; Wilson, Steve (2008). What Snake is that? Introducing Australian Snakes. Australia: Reed New Holland. p. 80. ISBN 9781877069574.
  8. ↑ Queensland Museum. "Western Brown Snake". Queensland Museum. Queensland Museum. Retrieved 10 October 2014.
  9. 1 2 3 Wilson, Steve; Swan, Gerry (2008). A Complete Guide to Reptiles of Australia (2nd ed.). Australia: New Holland Publishers. pp. 458–462. ISBN 9781877069468.
  10. ↑ The University of Adelaide. "CSL Brown Snake Anitvenom". CSL Antivenom Hand Book. The University of Adelaide. Retrieved 10 October 2014.
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