Elapid Snakes

Elapid snakes have teeth on the front part of the upper jaw that are modified as paired fangs to inject venom into their victims. The fangs deliver the venom in much the same way that a hypodermic syringe delivers a drug, i.e., as a subcutaneous injection under pressure through narrow tubes. The fangs of elapid snakes are permanently erect, and when the mouth is closed they are enclosed within a pocket in the outer lip, outside of the lower mandible. At any one time, only two fanged teeth are functionally capable of delivering venom. However, there are a series of smaller, developing fangs available as replacements, should the primary ones be damaged, lost during use, or shed. Elapid snakes bite to subdue their prey, and when attempting to protect themselves from their own predators.

Three species of elapid snakes have the ability to deliver their venom through the air, by "spitting" rather accurately towards the eyes of a predator, in some species to a distance of up to 9.8 ft (3 m). This is primarily a defensive behavior, rather than one used for hunting. The spitting cobra (Hemachatus hemachatus) of South Africa is especially accurate, and can propel its venom as far as 6.5 ft (about 2 m). Other spitting cobras are the African black-necked cobra (Naja nigricollis) and a subspecies of the Asian cobra (Naja naja sputatrix). If the venom of a spitting cobra is not quickly washed from the eyes, blindness could occur.

When cobras feel threatened, they will raise the front of their body above the ground, and face the danger. At the same time, cobras use extensible neck ribs to spread their so-called "hood," as a further warning to the potential predator. The erect stance and spread hood of cobras is a warning display, used to caution predators about meddling with a dangerous snake.

Most elapid snakes are oviparous, meaning they lay eggs, that after a period of incubation hatch into young that are small replicas of the adult animals. Some species of elapid snakes, most commonly cobras, guard their eggs until they hatch. Some species, including the spitting cobra, are ovoviviparous, meaning the eggs are retained within the body of the female until they hatch, so that live snakes are born. Australian snakes in the genus Denisonia are viviparous, meaning true eggs are never formed by the female, and live young are born.

The greatest recorded longevity of an elapid snake was for the forest cobra (Naja melanoleuca), which lived 29 years in captivity.

Fish-eating sea snakes can reach a body length of 9.2 ft (2.8 m) and occur in tropical waters in eastern Africa and the Red Sea, Asia, Australia, and many Pacific islands. Sea snakes have very toxic venom, but most species are not aggressive, and they rarely bite humans. Sea snakes have a laterally compressed, paddle-shaped tail, well adaptive to swimming, and most species are ovoviviparous. Some species of sea snakes occasionally form mass aggregations, probably for breeding, and such gatherings have been estimated to contain several million individuals.

One especially seafaring species, the pelagic sea snake (Pelamis platurus), ranges from the east coast of A Siamese cobra. Photograph by Tom McHug. The National Audubon Society Collection/Photo Researchers, Inc. Reproduced by permission.

Africa, through the Indo-Pacific region, and has even crossed the Pacific Ocean, occuring in tropical waters of western South America. Sea snakes are probably the basis of folk legends about sea serpents, although the living sea snakes do not closely resemble the fantastically large and aggressive serpents of folk lore.