The red-headed krait (''Bungarus flaviceps'') is a large venomous elapid snake with dramatic coloration. The red-headed krait can grow to a length of up to . It lives in lowland rain forest, including those on islands, but it is considered uncommon. It feeds primarily on specific snakes, probably semiaquatic and

fossorial A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric eviden ...

snakes. In Southeast Asia, the red-headed krait occurs in Malaysia, Singapore, Thailand, South India and Indonesia (

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

), with a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

in Borneo. The venom

potency Potency may refer to: * Potency (pharmacology), a measure of the activity of a drug in a biological system * Virility * Cell potency, a measure of the differentiation potential of stem cells * In homeopathic dilutions, potency is a measure of how ...

is little-studied, as bites from this species are extremely rare.

Description

The species presents a very striking and distinctive coloration – namely a bright red head and tail with a black body that includes a low-lateral narrow bluish white stripe. Having large, smooth scales, the general appearance of the red-headed krait is glossy and attractive. Captives will generally refuse to strike until they have been subjected to prolonged teasing. The average length of a red-headed krait is , with a maximum of .Snakes od Thailand – Krait
Siam-info.com. Retrieved on 2013-01-03. They have short, hollow fangs on their maxillary bones, with inlets at the bases and outlets near their tips. The venom is ducted to the inlet and forced through the hole at the tip of the fang. They are similar to another venomous snake, the blue Malayan coral snake ('' Calliophis bivirgata'') and the nonvenomous red-headed reed snake (''

Calamaria schlegeli ''Calamaria schlegeli'' is a species of snake in the family Colubridae. The species is known commonly as the red-headed reed snake, Iskandar D, Grismer L (2012)''Calamaria schlegeli''.The IUCN Red List of Threatened Species. Downloaded on 18 F ...

'').

Distribution and habitat

The red-headed krait occurs in southern

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

and Thailand, Cambodia, Vietnam, Peninsular Malaysia, Borneo, Singapore, and a number of Malaysian ( Pulau Tioman) and Indonesian islands ( Bangka,

, Java, Belitung Billiton. The subspecies ''B. f. baluensis'' is found in Sabah (Borneo). Red-headed kraits inhabit the rain forests in mountainous and hilly regions. They are hardly ever to be found in proximity to human habitations.

Behaviour

They are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

and partially aquatic. Once thought to feed primarily on other snakes, they are known to include skinks,

lizards Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia althou ...

, frogs,

caecilians Caecilians (; ) are a group of limbless, vermiform or serpentine amphibians. They mostly live hidden in the ground and in stream substrates, making them the least familiar order of amphibians. Caecilians are mostly distributed in the tropics o ...

, small mammals, and snake eggs in their diets. Despite their intrinsic deadliness, they are not usually considered of high risk to humans in the daytime. Variously described as sluggish, lethargic, and extremely inoffensive, they often remain hidden during the day and, when disturbed, press their heads into the ground or hide them in the flattened or rolled coils of their bodies. During the night, they are active and extremely dangerous.

Venom

The red-headed krait is an extremely venomous snake, although bites are reported rarely. Krait venom appears to function primarily as a

neurotoxin Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature ner ...

, preventing communication across neuromuscular

synapses In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from ...

, causing

paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...

and death by asphyxiation because the victims can no longer breathe on their own. When the venom from the red-headed krait takes effect, the most highly innervated muscles are the first to suffer: the muscle that elevates the upper eyelid and the ocular and ciliary muscles controlling the lens. Between 20 minutes and several hours after being bitten, the victim may struggle to keep his or her eyelids open. This medical condition is known as bilateral ptosis and it is a classic, tell-tale sign of severe envenomation. Other common symptoms include diplopia, dysphagia, vomiting, headache, and hypersalivation. Sometime later the symptoms of paralysis tend to worsen, with progressive involvement of various muscles, including those of the jaws, in some cases, become locked. Respiratory distress may occur as a result of paralysis of the

diaphragm Diaphragm may refer to: Anatomy * Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen * Pelvic diaphragm or pelvic floor, a pelvic structure * Urogenital diaphragm or triangular ligament, a pelvic structure Other * Diap ...

, the main muscle controlling breathing. Its venom also contains a novel postsynaptic neurotoxin, termed κ-flavitoxin, which is a potent inhibitor of nicotinic transmission in autonomic nervous system, autonomic ganglia. Neurotoxic symptoms may resolve naturally, or more rapidly through administration of antivenin or drugs that inactivate acetylcholinesterase, an enzyme which naturally destroys the chemical messenger carrying signals from nerves to muscles at the neuromuscular synapse.

References

External links

*
B. flaviceps at Thailand Snakes
Accessed 19 Dec 2014. {{Taxonbar, from=Q2382318 Bungarus Snakes of Southeast Asia Reptiles of Brunei Reptiles of Cambodia Reptiles of Indonesia Reptiles of Malaysia Reptiles of Myanmar Reptiles of Thailand Snakes of Vietnam Reptiles described in 1843 Taxa named by Johannes Theodor Reinhardt Reptiles of Borneo