According to scientists, 450 out of three thousand species of poisonous snakes are dangerous to humans. Poison for them is defense, a tool for hunting, and even a means for digesting food. Species of poisonous snakes are distributed mainly in the warm tropical regions of the planet. There they represent a real danger to people because of the large numbers. Sad statistics of fatal bites puts Africa, Indochina and South America in the first place. Cases of death from snakebites in Europe and the CIS are rare. In the CIS, most of them occur in the Caucasus and Central Asia. In total, 11 species of snakes dangerous to humans live in the CIS.
Different types of snakes have poison of different composition, action and strength. But, despite the differences, there is a unit of measure of the strength of the poison. This is DL50, where the letters are an abbreviation of Latin words meaning "lethal dose." It is expressed in the concentration of dry snake venom (μg / g - micrograms per gram), which is enough to kill the mouse. Now they consider the most poisonous snake from Australia Oxyuranus microlepidota.
Not only snakes inhabiting the land are poisonous, marine poisonous species of snakes are also found. The degree of danger of a bite depends not only on the strength of the poison itself, but also on its quantity, which can be introduced into the body of a snake. The record here belongs to the royal cobra and bushmeister. Open species of snakes that do not have toxic teeth, which are usually introduced poison. Their saliva is poisonous, it is just as dangerous to humans.
Some snakes are poisonous glands, for example, the royal aspid, common in Southeast Asia. Glands cover his entire body to the tip of his tail. The royal aspid goes hunting at night and moves hiding under the fallen leaves, so it is very difficult to notice.
But not all poisonous species of snakes lead such a secretive lifestyle. Russell's viper, she is a spectacle snake, does not hesitate to crawl even into a person’s home. Although her food is rats, frogs, poultry, she caused the death of so many people. She has an awesome look, on the drop-down hood - a bright pattern that resembles glasses in shape.
How does snake venom work? Types of snake venoms vary in the nature of their effects. Some coagulate blood vessels, others cause paralysis and cramps, affecting the nervous system and brain. Interestingly, the poison itself does not harm the snake. This is the result of evolution, because the poisonous species of snakes did not appear overnight. The poisonous glands that are in the mouth emerged from the altered salivary glands; in the course of natural selection, which lasted for thousands of years, the most resistant specimens remained.
Poisonous snakes have enemies that feed on them: brave, dexterous mongooses, an African secretary bird and, finally, our usual hedgehog. These animals also adapted and became less susceptible to the poison, although it acts on them, but is much weaker. Therefore, while hunting, they dodge a bite.
But snakes are immune only to their own poison. If a viper and a viper converge in a deadly duel, one of them will die.
The poison of snakes for humans is not only evil, it has long been used in medicine as a valuable medicine. Many nurseries for breeding snakes have been created, on which the so-called milking periodically passes. So the existence of poisonous snakes is necessary both in terms of biological balance and human benefits.
