Snake

We explain everything about snakes, their classification, habitat and other characteristics. Also, the most poisonous snakes.

What are snakes?

Snakes, snakes, vipers or snakes are a group of reptiles with a cylindrical, elongated, scaly body and no legs of which around 3,500 different species are known (from the clade Snakes), both in aquatic and terrestrial ecosystems. Famous for the poisonous bite of some of them, they are among the most feared animals that have most fascinated humanity since ancient times.

Snakes originated in the Cretaceous period, between 145 and 66 million years ago, from an ancestral reptile that is still unknown, but that at some point in its evolutionary history sacrificed its legs to better adapt to its environment.

However, not all limbless reptiles are snakes: the latter are recognized by their lack of mobile eyelids and external auditory openings, as well as their forked tongue that continually shake forward, to perceive their surroundings.

Snakes are among the oldest animals known to humans, and have a presence in mythologies and imaginaries of various ancient cultures, either as a sacred animal and divine representative (such as the feathered serpent of the Mesoamerican peoples: Quetzalcóatl), or as evil and seditious creature (as in the Judeo-Christian tradition, in which he represents Satan and is accused of having tempted Eve to sin).

Although cultural interpretations of the snake can vary greatly, it is common to find it in almost all human religious and literary traditions.

See also: Land animals

Characteristics of snakes

In general, snakes are characterized by the following:

• have an elongated and cylindrical body, with scaly skin whose thickness and length can vary enormously from one species to another, ranging from a few centimeters to several meters.
• Since they lack legs, move through undulating movements of the body which does not mean that they are slow or clumsy; Many species are excellent and agile swimmers, while others are stealthy hunters and good tree climbers.
• Like all reptiles, are poikilothermic animals, that is, cold-blooded unable to regulate body temperature autonomously.
• They have limited vision, focused on detecting movement, and an almost non-existent sense of hearing, replaced by an acute sense of perception of ground vibrations, and a heightened sense of smell centralized in the nose but helped by the tongue, which shoots out of the mouth to capture particles in the air and conduct them to the Jacobson's organ, located in the front part of the palate, where they are captured and analyzed.
• They do not have eyelids, but its eyes are covered by transparent scales. The entire skin is shed several times throughout life, when the animal needs to grow, and it is shed in one piece, as if the snake took off a sock.
• The snakes have complex teeth, adapted to their defense mechanisms generally composed of sharp and curved teeth, to hold the prey, some of which have a channel to inject toxins, in species equipped with venom. Snakes do not chew, but swallow their prey whole and then undertake a long digestion in complete immobility.

Snakes are a very diverse clade of animals, which can be classified as follows:

• Boas and pythons the most primitive snakes (some still have vestiges of legs) and most voluminous, devoid of venom, which coil around their prey and suffocate them by imprisoning them with their body (constriction).
• Snakes the vast majority harmless and medium-sized, adapted to various habitats (aquatic, arboreal, terrestrial), where they act as predators of small animals. A few species are poisonous and can pose a danger to humans.
• Elapids like cobras, corals and mambas, are the most poisonous and dangerous snakes of all, equipped with small fangs that inoculate a dose of neurotoxins with each bite. Very diverse among themselves, some have a threatening appearance or bright colors that denote their danger.
• Crolate them and vipers very venomous snakes that inject a hemolytic toxin with each bite, thanks to two large grooved fangs that fold inside the mouth when it closes. They have a recognizable triangular and wide head.

Where do snakes live?

The snakes have adapted to practically all habitats and can be found on all continents except Antarctica and the circumpolar regions. There are species of aquatic life, arboreal life (especially in tropical jungles), and even terrestrial species adapted to deserts.

What do snakes eat?

The snakes are exclusively carnivorous, since they are lethal hunters. Depending on the species, they can capture their prey and curl their bodies around them, suffocating them with the force of their muscles, or they can bite them to inoculate their venom, which consists of specialized digestive enzymes that paralyze or kill their prey. , while facilitating subsequent digestion.

Depending on the habitat and the species, Their diet may consist of insects, amphibians, fish, rodents, reptiles, birds or mammals of good size, which they ingest whole and without chewing; the indigestible parts are then regurgitated. Many species also feed on eggs, or other species of snakes.

How do snakes reproduce?

Most snakes are oviparous: they reproduce sexually and the fertilized female then deposits a variable number of eggs, usually in a nest that she herself fiercely guards. Other species, however, have developed ovoviviparous mechanisms, that is, the egg is formed inside the mother until it hatches, at which time the offspring is expelled from the mother's body. This way, no nests are needed.

How long do snakes live?

Given their enormous zoological variety, snakes have very different life expectancies, depending on the species. The largest ones live longer than the small ones, which can mean a period between 10 and 40 years of life.

The most poisonous snakes in the world

The most venomous species of snakes known are the following:

• puff adder or blower (Bitis arietans). The most dangerous snake in Africa, given its wide distribution on the continent and its powerful venom, capable of producing local and systemic damage to the body, such as swelling, necrosis, vomiting, shock and finally death. They measure around 1 meter long and their color ranges between brown and yellow.
• Cape Tree Snake (Dispholidus typus). Known in Afrikaans as “boomslang“, is a docile, shy snake from sub-Saharan Africa that can measure between 1 and 1.50 meters long. Their bite is rare in humans, since their venom glands are very far back in the mouth, requiring the person to manipulate them in order to bite in a thinner area. The poison, however, is a powerful slow-acting hemotoxin, which prevents coagulation and with just 5 mg it can cause the death of an adult person.
• Mapanare snake (Bothrops atrox). Native to northern and central South America, it is a jungle snake present in Colombia, Venezuela, Guyana, Suriname, Brazil and regions of Peru and Ecuador. It is feared due to its fast-acting hemotoxic venom, capable of producing kidney failure, coagulation problems, necrosis and cardiovascular failure. Mostly nocturnal, it has a size that ranges between 75 and 125 cm, and a brown, olive, beige, gray or brown color, designed to blend in with the dry leaves of the forest.
• Eastern diamondback rattlesnake (Crotalus adamanteus). The longest rattlesnake in existence, capable of measuring up to 2.40 meters, and one of the most venomous on the American continent, it has a yellowish-brown color, with the typical rattle or rattle at the end of the tail. Their bite is painful and their venom is a strong hemotoxin, but in general they bite only to defend themselves or when cornered.
• king cobra (Ophiophagus hannah). The largest known venomous snake, whose extension can reach 5 meters in length and whose diet consists almost exclusively of other snakes. Thin, olive or brown in color and with bronze eyes, it is an aggressive snake whose bite injects a large amount of neuro-cardio-toxic venom, which attacks the central nervous system, causing muscle paralysis, vertigo, acute pain, drowsiness and finally collapse. cardiac, sending the prey into an immediate coma. Death occurs due to respiratory failure.
• coral snake (Micrurus sp.). A set of various species of snakes called “coral”, present throughout the American continent, recognizable by their ringed body with variable patterns of black, red and yellow. Although its venom is one of the most powerful known, the narrowness of the animal's mouth and its low tendency to bite mean that not many cases of poisoning are recorded, since the person must be handling the snake.

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References

• “Snakes” on Wikipedia.
• “Snakes” in National Geographic.
• “The most impressive snakes in nature” in VERY Interesting.
• “Snakes, characteristics, distribution and threats” at CONICET Santa Fe (Argentina).
• “Types of Venomous Snakes” in Centers for Disease Control and Prevention (USA).
• “Snake (reptile)” in The Encyclopaedia Britannica.