Archives of The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 29, Number 3;   March, 2002

The King Cobra (Ophiophagus hannah)

by Vidyuth Chengappa
Undergraduate Student, Case Western Reserve University

The king cobra is an Elapid, but it is placed in a separate genus, Ophiophagus, from the true cobra, Naja, and is the only species in the Ophiophagus genus. The king cobra is considered to be the longest venomous snake, with a maximum length of 18 feet (5.4m). However, due to its threatened status, it is very rare to find king cobras approaching this length. Most of these snakes in captivity are an average of 13 feet (3.9m). The head is flat on top. The king cobra has black beady eyes. The neck is exaggerated due to folds of loose skin on either side of it. Depending on their environment, king cobras can be black, brown, yellow or green - interspersed with yellow or white crossbands. Generally speaking, king cobras found in dense forests are darker than those found in open forests or savannas. The pattern of the belly also varies, from a uniform light cream color to the cream color marked with dark bars. When the king cobra becomes agitated, ribs in the neck flatten out, expanding the folds of skin and creating a long, narrow hood. The hood lacks a pattern of any kind, distinguishing it from the true cobras. Adult king cobras shed their skin about 4-6 times per year, while juveniles shed their skin every month. The shedding process is much like that of other snakes. The king cobra's dorsal scales are small and rounded, without keels.

King cobras are found in northern and eastern India, east to southern China (including Hong Kong and Hainan), south throughout the Malay Peninsula, and also in the island nations Indonesia and the Philippines. The king cobra inhabits dense or open forests, mangrove swamps, bamboo thickets and savannas. They are often found around human settlements. With the ability to swim and climb trees, king cobras are designed to inhabit all sorts of territories. They also live at high altitudes, residing in the mountainous regions of India up to altitudes of 6500 feet above sea level.

The king cobra's diet mainly consists of other snakes, namely nonvenomous snakes such as Asian rat snakes and pythons (although they are known to eat Indian cobras, kraits, and even smaller king cobras), but they also feast on lizards, birds and small mammals. Some examples in captivity can turn out to be picky eaters, developing specification for a single species as a food resource. Like all other snakes, the king cobra hunts down its prey using its forked tongue and vomeronasal organ. When having detected the vicinity of the prey, they rely on their eyesight to guide them in making a strike. King cobras can raise their hood 1/3 their body length off the ground (about 5 feet), and can pursue any prey attempting to escape while in this raised position. After having attacked its prey, the king cobra injects its venom. This venom, as in other elapids, is stored in the venom glands behind the eyes. After its fangs are sunk into the prey, the king cobra expels its venom by contracting a muscle that surrounds the venom gland. The fangs are 1/2 inch in length and are attached to the upper jaw. The king cobra's venom is extremely toxic, having enough potency to kill an adult elephant. The venom affects respiratory centers in the medulla of the brain as well as interfering with the transmission of nerve impulses to muscles. In humans death may occur in a very short time, depending on the location of the bite. A certain toxin in the king cobra venom. Toxin CM55, is thought to be the active protein. There is currently much research going on studying this lethal, cardiotoxic, hemmorhagic protein toxin.

King cobras reach sexual maturity at 5-6 years of age. Breeding season begins in January, and is accompanied by a shedding of skin. In female cobras shedding releases pheromones, which help males find them. When they find each other, the male entwines its body around the female, and they stay in that position for up to two hours. The male's sperm eventually fertilizes the eggs and the female becomes gravid. The female can store sperm for several years, using it to impregnate herself several times. King cobras lead solitary lives, but male and female king cobras will sometimes remain mating partners for life. They cooperate in finding a nest site, which is the area where the eggs are laid. To build a nest, the female pushes leaves and branches into a nest pile where the eggs are incubated by the elevated temperatures of decomposition. After a 60-70 day incubation period, the eggs hatch and the juveniles emerge. During the incubation period the female is very protective of the nest. Just before the baby snakes are born, however, she abandons her nest -- possibly to keep herself from eating her own young. The juveniles are glossy black at birth with yellow bands. The babies measure 14 inches (35 cm) in length and are about I/2 an inch (1.25 cm) wide. Their venom is just as potent as that of an adult, and at 10 days they are ready to hunt.

King cobras have very few natural predators as adults, but the young are frequently preyed upon by mongooses, army ants, and giant centipedes. The biggest hindrance to the survival of king cobras is mankind. Habitat destruction drives them into populated areas, where they are killed due to misplaced fears that they are savage attackers. In reality, even though the king cobra is considered an aggressive animal, it is likely to avoid any contact with humans and quick to slither away from people (unless it is protecting its nest). King cobras are also killed for commercial purposes. Their skin, meat, and bile are used in ancient Chinese medications. Their venom is used to treat tuberculosis, and is also used to produce antivenin.

References:
Dasgupta, S.C.; Pallabi, De; and Gomes, A. "Occurrence of a Unique Protein Toxin from the Indian King Cobra (Ophiophagus hannah) venom." Toxin 39 (2001) 363-370.

www.animaldiversity.ummz.umich.edu/accounts/ophiophagus/ 0._hannah$narritive.html

www.the-planet.net/co/animal/kcobra.html

www.nationalgeographic.com/features/97/kingcobra/