Dwyer's snake (Suta dwyeri)[3] also known as the [4] variable black-naped snake,[2][5] is a species of venomous snake in the family Elapidae. The species is endemic to Australia, where it is found from New South Wales to South Queensland.[2][6][7] While closely related to Australian sea snakes,[7] S. dwyeri is a terrestrial reptile.[8]

Dwyer's snake
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Suta
Species:
S. dwyeri
Binomial name
Suta dwyeri
(Worrell, 1956)
Synonyms[2]
  • Denisonia dwyeri
    Worrell, 1956
  • Unechis dwyeri
    Cogger, 1983
  • Suta dwyeri
    Valentic, 1998
  • Suta spectabilis dwyeri
    — Cogger, 2000
  • Parasuta dwyeri
    Greer, 2006
  • Parasuta spectabilis dwyeri
    — Cogger, 2014
  • Suta dwyeri
    Maryan et al., 2020

Etymology

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The specific name, dwyeri, is in honor of Australian herpetologist John Dwyer.[9]

Taxonomy

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There has been a great amount of instability of the nomenclature of many Australian snake taxa, particularly concerning the generic classification of the smaller Elapidae, some of which have been placed in several different genera in the span of just a few decades.[10]

Accordingly, Dwyer's snake, which was originally named Denisonia dwyeri by Worrell in 1956, has been variously called Unechis dwyeri by Cogger in 1983, Suta dwyeri by Valentic in 1998, Suta spectabilis dwyeri by Cogger in 2000, and Parasuta dwyeri by Greer in 2006.[2]

Description

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Adult S. dwyeri males average 31 cm (12 inches) in length from the tip of the snout to the uro-genital vent. Females are slightly smaller at around 29 cm (11 inches) in snout-to-vent length (SVL).[11] S. dwyeri has a cylindrical brown body with a slender to medium build. The head is short and somewhat widened so as to be distinct from the neck. The tail is short as well, and the dorsal scales are smooth. The eye is medium-sized, with a vertically elliptical pupil.[12]

Reproduction

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Breeders of exotic reptiles advise letting pairs of S. dwyeri mate when they reach a length of about 23 cm (9.1 in) for males and 22 cm (8.7 in) for females. This species is viviparous rather than egg laying and successfully births about three offspring per brood. Newborn S. dwyeri young are about 13 cm (5.1 in) long.[11]

Defense mechanisms

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Like other snakes in the family Elapidae, S. dwyeri is venomous and has hollow fangs fixed at the front of the upper jaw. These fangs are connected via ducts to venom glands near the eyes. Like the majority of Australian elapids, Dwyer's snake is inoffensive and shy. In addition, Herpetologists at the Queensland Museum describe Dwyer's snake as "weakly venomous", and do not include it among their list of eight snake species in the Brisbane area considered capable of inflicting potentially fatal bites.[8] A 25-year-old man in Western Sydney mildly describes a snakebite from this species by saying that he was:

... bitten on the finger by a Suta dwyeri once. The bite did not hurt at all. But little did I know he had left his fang in my finger. A couple of days later it got a tiny bit infected and hurt for a couple of days ... nothing major though.[13]

When threatened P. dwyeri prefers to coil into a tight ball as a defense mechanism for protection from larger predators. This enables the snake to protect its head and more vulnerable areas of its body.[4]

Behaviour and habitat

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S. dwyeri is a secretive, nocturnal snake that seeks shelter under rocks, debris, and ground litter, and may make its home in burrows made and abandoned by other creatures. Open woodland, grassland, and rocky areas are its preferred natural habitats.[1]

Diet

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S. dwyeri feeds mainly on small lizards such as geckos and skinks.[12]

Images

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References

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  1. ^ a b Vanderduys E, Wilson S, Hobson R, Sanderson C (2018). "Parasuta dwyeri ". The IUCN Red List of Threatened Species 2018: e.T102710963A102711010. https://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T102710963A102711010.en. Downloaded on 19 October 2018.
  2. ^ a b c d [1] "Suta dwyeri ". The Reptile Database. www.reptile-database.org.
  3. ^ [2] Queensland Museum
  4. ^ a b [3] "Balling as a defence mechanism for snakes", Journal of the Herpetological Society of Queensland, Spring 2005
  5. ^ [4] Archived 2008-02-09 at the Wayback Machine Common Names of Australian Reptiles
  6. ^ [5] Elapidae
  7. ^ a b [6] Snake Tracks Species List
  8. ^ a b [7] Elapid Land Snakes (Family Elapidae, Subfamily Elapinae): South-east Queensland
  9. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Suta dwyeri, p. 79).
  10. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2006-12-25. Retrieved 2006-12-25.{{cite web}}: CS1 maint: archived copy as title (link) The good, the bad and the ugly: Australian snake taxonomists and a history of the taxonomy of Australia’s venomous snakes
  11. ^ a b [8] Size and Breeding Information for Australian Snakes
  12. ^ a b [9] Clinical Toxinology Resources
  13. ^ [10][permanent dead link] Aussie Pythons & Snakes (aussiepythons.com)

Further reading

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  • Cogger HG (2000). Reptiles and Amphibians of Australia, Sixth Edition. Sanibel Island, Florida: Ralph Curtis Publishing. 808 pp.
  • Cogger HG (2014). Reptiles and Amphibians of Australia, Seventh Edition. Clayton, Victoria, Australia: CSIRO Publishing. xxx + 1,033 pp. ISBN 978-0643100350.
  • Coventry AJ (1971). "Identification of the Black-headed Snakes (Denisonia) within Victoria". Victorian Naturalist 88: 304–306. (Denisonia dwyeri, p. 305, Figure 1C).
  • Valentic R (1998). "A size record and further distributional data for Suta dwyeri (Elapidae) in the Sydney Basin". Herpetofauna (Sydney) 28 (1): 30–31.
  • Wilson S, Swan G (2013). A Complete Guide to Reptiles of Australia, Fourth Edition. Sydney: New Holland Publishers. 522 pp. ISBN 978-1921517280.
  • Worrell E (1956). "A new snake from Queensland". Australian Zoologist 12: 202–205. (Denisonia dwyeri, new species).