Inland Taipan

The inland taipan (Oxyuranus microlepidotus), also commonly known as the western taipan, the small-scaled snake or the fierce snake, is an extremely venomous snake of genus Oxyuranus, and is endemic to semi-arid regions of central east Australia. Aboriginal Australians living in those regions named the snake Dandarabilla.

Although extremely venomous and a capable striker, in contrast to the rather aggressive coastal taipan, the inland taipan is usually quite a shy and reclusive snake, with a placid disposition, and prefers to escape from trouble. 

However, it will defend itself and strike if provoked, mishandled, or prevented from escaping. Because it lives in such remote locations, the inland taipan seldom comes in contact with people; therefore it is not considered the deadliest snake in the world overall, especially in terms of disposition and human deaths per year. 

"The word "fierce" from its alternative name describes its venom, not its temperament."

The inland taipan first came to the attention of Western science in 1879. Two specimens of the fierce snake were discovered in the junction of the Murray and Darling Rivers in northwestern Victoria and described by Frederick McCoy, who called the species Diemenia microlepidota, or small-scaled brown snake.

The inland taipan inhabits the black soil plains in the semi-arid regions where Queensland and South Australia borders converge.

The inland taipan is dark tan, ranging from a rich, dark hue to a brownish light-green, depending on season. Its back, sides and tail may be different shades of brown and grey, with many scales having a wide blackish edge. 

These dark-marked scales occur in diagonal rows so that the marks align to form broken chevrons of variable length that are inclined backward and downward. The lowermost lateral scales often have an anterior yellow edge. 

The dorsal scales are smooth and without keels. The round-snouted head and neck are usually noticeably darker than the body (glossy black in winter, dark brown in summer), the darker colour allowing the snake to heat itself while exposing only a smaller portion of the body at the burrow entrance. 

The eye is of average size with a blackish brown iris and without a noticeable coloured rim around the pupil.

The inland taipan averages approximately 1.8 metres (5.9 ft) in total length, although larger specimens can reach total lengths of 2.5 metres (8.2 ft). Its fangs are between 3.5 and 6.2 mm long (shorter than those of the coastal taipan).

In the wild, the inland taipan consumes only mammals, mostly rodents, such as the long-haired rat (Rattus villosissimus), the plains rat (Pseudomys australis), the introduced house mouse (Mus musculus) and other dasyurids. In captivity it may also eat day-old chicks.

Inland taipans are rarely encountered in the wild by the average person because of their remoteness and brief above-ground appearance during the day. So long as a person is not creating much vibration and noise the inland taipan may not feel alarmed or bothered by a human presence. However, caution should be exercised and a safe distance maintained as it can inflict a potentially fatal bite. 

The inland taipan will defend itself and strike if provoked, mishandled, or prevented from escaping. Firstly, but not always, it makes a threat display by raising its forebody in a tight low S-shaped curve with its head facing the threat.

The average quantity of venom delivered by this species is 44 mg and the maximum dose recorded is 110 mg, compared to the Indian cobra (Naga raja) 169 mg/max 610 mg, and the North American eastern diamondback rattlesnake (Crotalus adamanteus) 410 mg/max 848 mg etc.

The first local and general symptoms of a bite are local pain and variable non-specific effects which may include headache, nausea, vomiting, abdominal pain, diarrhoea, dizziness, collapse or convulsions leading to major organ effects: neurotoxicity, coagulopathy, rhabdomyolysis or renal failure/damage and finally death.

Inland taipan snake venom contains potent presynaptic neurotoxins (toxins in venom that cause paralysis or muscle weakness). Also present are postsynaptic neurotoxins, which are less potent but more rapid acting than the presynaptic neurotoxins. Presynaptic neurotoxins disrupt neurotransmitter release from the axon terminal. This takes days to resolve and does not respond to antivenom.

The venom also contains a potent hemotoxin (procoagulants) a prothrombin activator that leads to consumption of major coagulation factors including fibrinogen, toxins in venom that interfere with blood clotting. This causes defibrination, with non-clottable blood, putting victims at risk of major bleeding from the bite site and can lead to more serious, sometimes fatal, internal haemorrhaging, especially in the brain.

The coastal taipan anti-venom, known as "taipan antivenom", is effective against the inland taipan venom as well, but it is not as effective in bite victims of the inland taipan as in those of the coastal taipan.