The king cobra (Ophiophagus Hannah) is a well-known venomous snake species from the family Elapidae, native to forests from India to Southeast Asia.
It is also called the hamadryad. The king cobra is listed on the IUCN Red List as Vulnerable, due to habitat destruction.
It is regarded as the world’s longest venomous snake. An adult king cobra is 10.4 – 13.1 ft (3.18 – 4 m) long on average. The longest known king cobra measured 19.2 ft (5.85 m).
The king cobra is the only known member of the genus Ophiophagus, and it preys mainly on other snakes. It occasionally preys on vertebrates, such as rodents and lizards.
It is a dangerous and highly venomous snake when provoked or agitated, although, it is shy and tries to avoid confrontations with humans.
The king cobra is regarded as the national reptile of India. It is also the prominent symbol in the folk traditions and mythology of Sri Lanka, India, and Myanmar.
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Most king cobras’ skins are olive green with a black and white band on the trunk that coincides to the head.
The head of a king cobra is covered by 15 drab-coloured and black-edged shields. The tongue is black and the muzzle rounded. It has two fangs and 3 to 5 maxillar teeth in the upper jaw, and 2 rows of teeth in the lower jaw.
The nostrils are between 2 shields. The eyes have rounded pupils and a golden iris. It has 15 rows on the body and 17 – 19 rows of smooth oblique scales on the neck.
Juveniles are black with yellow, chevron-shaped white or buff bars that point towards the head. An adult king cobra is 10.4 – 13.1 ft (3.18 – 4 m) long. The longest known specimen measured 19.2 ft (5.85 m).
The king cobra is known to be sexually dimorphic, with the male being paler and larger, especially during the mating season.
Males captured in Kerala measured up to 12.3 ft (3.75 m) and weighed up to 22 lb (10 kg). Females captured had a maximum length of 9 ft 0 in (2.75 m) and a weight of 11 lb (5 kg).
The head of a well-grown king cobra can be quite bulky and massive in appearance. Similar to all snakes, the king cobra expands its jaws to swallow large prey. The king cobra typically weighs about 13 lb (6 kg).
A captive individual at the London Zoo grew to 18.7 ft (5.71 m). In 1951, at the Royal Island Club in Singapore, the heaviest wild specimen was caught, and it weighed 26 lb (12 kg) & measured 16 ft (4.8 m).
A specimen kept at Bronx Zoo weighed 28 lb (12.7 kg) and was 14 ft (4.4 m) long in 1972.
The female is gravid for 50 – 59 days. The king cobra is known to be the only snake that builds a nest made out of leaf litter, starting from late March – late May.
Most nests are found at the base of trees and are up to 22 in (55 cm) high in the center and 55 in (140 cm) wide at the base. The nest may consist of several layers and often have one chamber, into which the females lays her eggs.
Clutch size ranges from 7 – 43 eggs, with 6 – 38 eggs hatching after incubation periods of 66 – 105 days. The temperature inside the nest is not constant but varies depending on elevation from 56.3 – 99.3 °F (13.5 – 37.4 °C).
Females stay by their nests between 2 – 77 days. Hatchlings are between 14.8 – 23.0 in (37.5 – 58.5 cm) long and weigh 0.32 – 1.34 oz (9 – 38 g). Hatchlings have the same venom potency as the adults.
Hatchlings are nervous and alert, being aggressive if disturbed. The lifespan of a wild king cobra is estimated to be around 20 years.
The king cobra’s diet consists mainly of lizards and other snakes, including banded krait, pythons, rat snake, Indian cobra, green whip snake, banded wolf snake, keelback, and Blyth’s reticulated snake.
It also hunts hump-nosed pit viper and Malabar by following their odour trails. During food scarcity, king cobras are known to feed on other small vertebrates, such as lizards and birds.
The king cobra has a slow metabolic rate which allows it to live for several months after taking a large meal.
Habitat and distribution
The king cobra has a wide distribution in Southeast and South Asia. It ranges up to an elevation of 6,600 ft (2,000 m) from southern Nepal and Terai in India to the Brahmaputra River basin in northeast India and Bhutan, Bangladesh and Myanmar, Cambodia, southern China, Laos, Thailand, Malaysia, Vietnam, Indonesia, Singapore, and the Philippines.
In northern India, it has been recorded in Kumaon and Garhwal, and the Terai and Shivalik regions of Uttarakhand and Uttar Pradesh.
In northeast India, the king cobra has occurred in northern West Bengal, Assam, Sikkim, Arunachal Pradesh, Meghalaya, Manipur, Nagaland, and Mizoram.
In the Eastern Ghats, it occurs from Andhra Pradesh and Tamil Nadu to coastal Odisha and also in southern West Bengal and Bihar especially the Sunderbans. In the West Ghats, it occurred in Karnataka, Kerala, and Maharashtra.
The king cobra’s venom consists of neurotoxins and cytotoxins, including three-finger toxins and alpha-neurotoxins. Other components of the venom have cardiotoxic effects.
The toxins in the venom affect the victim’s central nervous system (CNS), resulting in blurred vision, severe pain, drowsiness, vertigo, and eventually paralysis.
The victim may fall into a coma if the envenomation is serious, and it continues to progress into cardiovascular collapse. The victim can die within 30 minutes of envenomation. Not all bite leads to envenomation.
A protein component in the venom called ohanin, which causes hyperalgesia and hypolocomotion in mammals. Reversing the progression of symptoms may require large quantities of antivenom.