Biology:Pseudonaja mengdeni

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Short description: Highly venomous snake native to Western Australia


Western brown snake
Darwin July 2014 832.jpg
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Pseudonaja
Species:
P. mengdeni
Binomial name
Pseudonaja mengdeni
(Wells & Wellington, 1985)

The western brown snake (Pseudonaja mengdeni) is commonly known as Mengden's brown snake,[2] and alternatively, gwardar.[3]

Pseudnaja mengdeni is endemic to Australia . It is highly variable in colour and patterns[2] and is a highly dangerous elapid whose bite can cause severe symptoms resulting in death.[4] It is one of the three species originally classified as Pseudonaja nuchalis along with P. aspidorhyncha, and P. nuchalis.[3]

Taxonomy

Previously the western brown snake was considered a 'morph' form of Pseudonaja nuchalis, recent genetic studies have proven it to be genetically unique.[5]

It is estimated that Pseudonaja nuchalis could include in excess of 10 different species.[5] 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.[5]

Description

Pseudonaja mengdeni grows up to a total length of 2m[2] with an average length 1.2m[5] It has slender body and narrow head.[6] Mengden's brown snake is highly variable in colour and patterns, ranging from light brown to almost black.[2] However it has two distinct forms ‘Orange with black head’ or ‘Pale head, grey nape’[3] The underside along the belly is often cream, yellow, orange, or grey in colouration, frequently consisting of dark orange or grey blotches.[2]

Scales on the head often form a black V or W pattern.[6] Western brown snakes can be confused with the Eastern brown snake which has a pink mouth lining,[4] the Northern brown snake has a purplish/blue-black mouth lining.[7][8] P. mengdeni has a distinctive large strap-like scale around the front of the snout.[8] 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.[2] However this must only be done by an experienced herpetologist, as a scratch from the fangs can still be fatal from P. mengdeni.[4]

Confusion between the species is largely due to the possible hybridisation between the Pseudonaja species.[3]

The western brown snake is often confused with other Pseudonaja spp. (brown snakes) and also Aspidites melanocephalus (black headed python).[3]

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[2] however it is absent from wetter areas of eastern Australia and south-western Western Australia.[9]

Pseudonaja 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.[2][10] The Western brown snake often found within fallen timber, dead trees, shrubs, native grasses and ground cavities.[4]

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

Diet

Pseudonaja mengdeni preys upon small reptiles, mammals, other snakes, ground nesting birds and bird eggs.[2]

Reproduction

Pseudonaja mengdeni is oviparous and can lay up to in excess of 12 eggs per clutch.[5]

Venom

Pseudonaja mengdeni has highly dangerous venom neurotoxic and haemotoxic[3] and can cause severe symptoms resulting in death.[4] Mengden's brown snake is considered dangerously venomous.[10]

Antivenom used in case of envenoming is the brown snake Antivenom[11] If bitten first aid must be applied and medical attention sought.

Behaviour

Pseudonaja mengdeni will rear their fore-body into an S-shape when threatened[10] lifting their head off the ground and open their mouth.[4] Is also a terrestrial species that is diurnal however it can be active on warm nights[4]

References

  1. Shea, G., Oliver, P., Wilson, S. & Ellis, R. (2017). "Pseudonaja mengdeni". IUCN Red List of Threatened Species 2017. https://www.iucnredlist.org/species/42495921/42495923. Retrieved 2021-02-13. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Cogger, Harold (2014). Reptiles and Amphibians of Australia (7th ed.). Australia: CSIRO Publishing. p. 926. ISBN 9780643100350. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Beatson, Cecilie. "Animal Species: Western Brown Snakes (nuchalis-complex)". Australian Museum. http://australianmuseum.net.au/Western-Brown-Snakes. Retrieved 10 October 2014. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 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. https://archive.org/details/reptilesnswmurra00mich. 
  5. 5.0 5.1 5.2 5.3 5.4 Wells, Richard (2002). "Taxonomy of the genus Pseudonaja (Reptilia: Elapidae) in Australia". Australian Biodiversity Record (7): 8. ISSN 1325-2992. http://www.kingsnake.com/aho/pdf/menu2/wells2002.pdf. 
  6. 6.0 6.1 Edwards, Belinda (2011). Australian Snakes a Pictorial Guide. Australia: The Five Mile Press Pty Ltd. p. 63. ISBN 9781742116181. 
  7. 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. 
  8. 8.0 8.1 Swan, Gerry; Wilson, Steve (2008). What Snake is that? Introducing Australian Snakes. Australia: Reed New Holland. p. 80. ISBN 9781877069574. 
  9. Queensland Museum. "Western Brown Snake". Queensland Museum. http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Reptiles/Snakes/Common+and+dangerous+species/Western+Brown+Snake#.VDhm8vmSyDE. Retrieved 10 October 2014. 
  10. 10.0 10.1 10.2 Wilson, Steve; Swan, Gerry (2008). A Complete Guide to Reptiles of Australia (2nd ed.). Australia: New Holland Publishers. pp. 458–462. ISBN 9781877069468. 
  11. The University of Adelaide. "CSL Brown Snake Anitvenom". The University of Adelaide. http://www.toxinology.com/generic_static_files/cslavh_antivenom_brown.html#basic. Retrieved 10 October 2014. 

Wikidata ☰ Q3409783 entry