Cobra Snakes

Introduction
The cobra snake is the largest venomous snake in the world and probably also the deadliest in terms of known human deaths caused by a snake. Just like the coral snake (see the navigation panel to your right) they belong to the Elapidae family. Snakes in this family are found around the world including the Indian Ocean and the Pacific. The cobra snake can reach a length of almost 6 meter.

Most venomous snakes in Australia are Elapids and in some subtropical areas particularly in the rural tropics, deaths caused by Elapids is significant medical problem (White 2000)

Diet and Nutrition
Their preferred preys are rodents and birds. They does however also eat other snakes and some particular species as for instance the King Cobra, is said to have a preference for snakes. They kill their prey by injecting their neurotoxic poison into the prey through their fangs. The neurotoxin of cobra snakes has the ability of destroying the communication across the connection constituting the contact points between nerve cells. When this communication is destroyed the victim's muscles cannot be used in any kind of defense.

Habitat
Most Cobra snakes are found in desert regions of Africa and Asia.

Bite from a Cobra Snake
Not all cobra bites are venomous; some bites are so called dry bites which may cause serious infections due to bacteria from the cobras mouth. It is estimated that approximately 75 % of people receiving a bite from a Cobra Snake will eventually die from the medical complications arising from the bite. A real (not dry) bite from a cobra snake will in the most severe cases cause death within 10 minutes. Since its neurotoxic venom acts by inhibiting the transfer of transmitter substances across the synaptic cleft, mechanical ventilation of a victim may be a way of increasing the victims chance of survival. If antivenin is applied prompt its of uttermost importance, that the species that caused the bite is identified, since correct management of the patient is dependent on the prompt administration of the correct antivenin (Britt & Burkhart 1997)2.

Life Cycle
Some, but not all cobras, build small nests where the females lay there eggs. The number of laid eggs varies from season to season and depends on weather and the amount of food available etc. An average of 20 to 40 eggs is however normal. The eggs are laid approximately 9 weeks after mating. New cobras emerge after two too two and a half month. The mother leaves the eggs, by instinct, just before they hatch. This is a smart trick from Mother Nature because else she will eat the eggs in most cases, even though it sounds like an illogical behavior. The baby cobra snakes are venomous right from the start and they have a length depending on species.

King Cobra
The king cobra has a special preference for other snakes but it will also feed on small lizards and even mammals. Its found in Asia where it prefers to live in tropical forests and grassland. It is 10-12 feet long and will attack if provoked even though it's considered shy.
This cobra snake can be found in India, southern parts of China, in the Phillipines and in Malaysia. The snake occupies a wide range of habitats but prefers areas with access to water. It is by the way an excellent swimmer.

Spitting Cobra
Several species of the cobra snakes has the ability of spitting. It is used as a defense against predators. Generally a human can't die from a spit by a cobra snake. The venom in the snakes saliva can however cause permanent blindness and give scars if untreated.

References
1White J "Bites and stings from venomous animals: A global overview" THERAPEUTIC DRUG MONITORING Vol. 22 pp 65-68 (2000)
2Brit A & Burkhart "Naja naja cobra bite" AMERICAN JOURNAL OF EMERGENCY MEDICINE Vol. 15 (5) page 529-531 (1997)