The
king cobra (Ophiophagus hannah) is the world's longest venomous
snake, with a length up to 5.6 m (18.5 ft). This species is widespread throughout Southeast
Asia and parts of India, and is found mostly in forested areas. The
king cobra can be fierce, agile, and can deliver a large quantity of highly potent venom in a single bite. It is one of the most dangerous and feared
Asiatic
snakes.
The skin of this
snake is either olive-green, tan, or black, and it has faint, pale yellow cross bands down the length of the body. The belly is cream or pale yellow, and the scales are smooth. Juveniles are shiny black with narrow yellow bands (can be mistaken for a banded krait, but readily identified with its expanded hood). The head of a mature
snake can be quite massive and bulky in appearance, though like all
snakes, they can expand their jaws to swallow large prey items. It has proteroglyph dentition, meaning it has two short, fixed fangs in the front of the mouth which channel venom into the prey like hypodermic needles. The male is larger and thicker than the female. The average lifespan of a
king cobra is about 20 years.
The venom of the
King Cobra consists primarily of neurotoxins, but it also contains cardiotoxic compounds. and they are composed mostly of proteins and polypeptides.
During a bite, venom is forced through the
snake's half-inch (1.25 cm) fangs and into the wound, quickly attacks the victim's central nervous system, and induces severe pain, blurred vision, vertigo, drowsiness, and paralysis. Envenomation progresses to cardiovascular collapse, and the victim falls into a coma. Death soon follows due to respiratory failure.
In the past, the LD50 of the
king cobra's venom was treated as 1.6 mg/kg – 1.8 mg/kg (which was one of the least venomous elapids). However, a recent toxicology study indicates that the LD50 of Chinese
King Cobra venom is 0.34 mg/kg lower than many Naja species that are found in the same habitats, thus proving that the
king cobra can actually be more venomous than many cobras in its range (such as the Chinese cobra). The
King Cobra is also capable of delivering larger quantities of venom than most other
snakes, injecting a 380-600 mg dose in a single bite on average. This quantity is enough to kill 20-40 grown men or even an adult elephant. One bite can cause the death of a healthy adult human within 15 minutes, though the average death time is between 30–45 minutes after envenomation. The mortality rate from a bite can be over 75%, or only 33%, depending upon treatment details. It is regarded as one of the deadliest
snakes in the world.
There are two types of antivenom made specifically to treat
King Cobra envenomations. The Red Cross in Thailand manufactures one, and the Central Research Institute in India manufactures the other; however, both are made in small quantities and are not widely available. Ohanin, a protein component of the venom, causes hypolocomotion and hyperalgesia in mammals. Other components have cardiotoxic, cytotoxic and neurotoxic effects