The red-bellied black snake (Pseudechis porphyriacus) is a species of elapid snake native to eastern Australia. Though its venom is capable of causing significant morbidity, a bite from it is not generally fatal and is less venomous than other Australian Elapid snakes. It is common in woodlands, forests and swamplands of eastern Australia. It is one of Australia's best-known snakes, as it is common in urban areas along the eastern coast of Australia. It has an average total length (including tail) of 1.5 to 2 metres (4Â ft 11Â in to 6Â ft 7Â in).
Taxonomy
The red-bellied black snake was described by George Shaw in Zoology of New Holland (1794), placing it in the genus Coluber. He wrote, "This beautiful snake, which appears to be unprovided with tubular teeth or fangs, and consequently not of a poisonous nature, is three, sometimes four, feet in nature." The species name is derived from the Ancient Greek porphyreus, which can mean "dark purple", red-purple" or "beauteous". It was the first Australian elapid snake described. The accompanying illustration was attributed to James Sowerby, but is regarded as being produced from drawings by John White. The syntype is presumed lost. French naturalist Bernard Germain de Lacépède described it under the name Trimeresurus leptocephalus in 1804. His countryman René Lesson described it as Acanthophis tortor in 1826.
The genus Pseudechis was created for it by Johann Georg Wagler in 1830, though several subsequent species have been added.
Snake expert Eric Worrell analyzed the skulls of the genus and found that of the red-bellied black snake to be the most divergent. its position as an early offshoot from the rest of the genus has been confirmed genetically.
Raymond Hoser described two subspecies in 2003: Pseudechis porphyriacus eipperi the Atherton Tableland and surrounds in North-east Queensland, which he noted was smaller, rarely attaining 2Â m (7Â ft) and had a white or pale pink rather than red belly, and Pseudechis porphyriacus rentoni from southeastern South Australia, which has a variable-coloured (often orange or even blueish-tinged) belly. He added that both were disjunct from the main red-bellied black snake population, and as the distinguishing traits of P. porphyriacus rentoni were not consistent then location was the most reliable way of identifying it. These subspecies have not been recognized by other authors. Hoser has been criticized by Hinrich Kaiser and colleagues for identifying some taxa on location alone.
As well as red-bellied black snake, the species has been called common black snake, redbelly and RBBS.
Description
The red-bellied black snake is glossy black on the dorsal surface and red, crimson or pink in colour on the lower sides and belly. The snout is often a lighter brown colour. It is a relatively medium species of snake reaching up to 2 metres (6Â ft 7Â in) in total length (including tail), with an extreme example measuring 2.5 metres (8Â ft 2Â in), although an average sized specimen would be closer to 1.4 metres (4Â ft 7Â in). Like all Elapid snakes it is front fanged. It has 17 mid-body scale rows. Juveniles are similar to the eastern small-eyed snake, with which it can be easily confused.
Other similar species include the blue-bellied black snake (Pseudechis guttatus) and copperheads of the genus Austrelaps.
Distribution and habitat
The red-bellied black snake is native to the east coast of Australia. It can be found in the urban forest, woodland, plains and bushland areas of the Blue Mountains, Canberra, Sydney, Brisbane, Melbourne, Cairns and Adelaide.
The Macquarie Marshes marks a western border to their distribution in New South Wales.
It is most commonly seen close to dams, streams, billabongs and other bodies of water, although they can venture up to 100 m away. Red-bellied black snakes have multiple places they can hide in their habitat including logs, old mammal burrows, and grass tussocks.
Disposition and behaviour
The red-bellied black snake is generally not an aggressive species. However, when provoked, it will recoil into its striking stance as a threat, but will try to escape at the first opportunity. It is most active by day. When not hunting or basking it may be found beneath timber, rocks and rubbish or down holes and burrows.
Snakes are active when their body temperatures are between 28 and 31 C.
Diet
The diet of red-bellied black snake primarily consists of frogs, but it also preys on reptiles and small mammals. They also eat other snakes, including those of their own species.
Venom
The red-bellied black snake accounted for 16% of identified snakebite victims between 2005 and 2015, with no deaths recorded.
The venom of red-bellied black snake consists of neurotoxins, mycotoxins, coagulants and also has haemolytic properties. Bites from red-bellied black snake are rarely life-threatening, but need of immediate medical attention. Symptoms of systemic envenomationâ€"including nausea, vomiting, headache, abdominal pain, diarrhoea or diaphoresisâ€"were thought to be rare, but a 2010 review found they occurred in most bite victims. Most people also go on to develop an anticoagulant coagulopathy in a few hours. This is characterised by a raised aPTT, and subsides over 24 hours. It resolves quickly with antivenom. A few people go on to develop a myotoxicity and associated generalised muscle pain and occasionally weakness, which may last for up to 7 days.
Tiger snake antivenom is used to treat bites. While black snake antivenom can be used, tiger snake antivenom can be used at a lower dose. The smaller dose is cheaper to produce, and is less likely to cause a reaction in the patient. Patients may suffer anosmia.
Reports of dogs being bitten are rare. In 2006, a 12 year old golden retriever suffered rhabdomyolysis and acute renal failure secondary to a redbellied black snake bite.
Reproduction
Red-bellied black snakes are ovoviviparous; that is, they give birth to live young in individual membranous sacs. The young, numbering between eight and forty, emerge from their sacs very shortly after birth, and have an average length of about 122 millimetres (4.8Â in). In the wild, few will survive to reproduce.
Captivity
Red-bellied black snakes adapt readily to captivity and live on a supply of mice.
References
Further reading
- Boulenger GA (1896). Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphae) ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (Pseudechis porphyriacus, pp. 328â€"329).
External links
- Red-bellied Black Snake video
- Pictures of Red-bellied Black Snake's fangs
- Red-bellied Black Snake â€" Australian Venom Research Unit, Department of Pharmacology, the University of Melbourne
Data related to Pseudechis porphyriacus at Wikispecies Media related to Pseudechis porphyriacus at Wikimedia Commons