We fear them as they have the potential to kill us with their venom. They’re snakes. Snakes belong to the suborder Serpents and are legless, crawling and elongated reptiles. They’re different from lizards as they lack eyelid and external ears. The skull bones of snakes have been demarcated by presence of a large number of joints which let them feed on a prey which is much bigger than them. Jaws are highly movable. They’ve a single functional lung. Some species bear a set of vestigial claws on either side of the cloaca. Fifteen families are recognized comprising of 456 genera and 2,900 species. They range in size from 10 cm like that of thread snake to the bigger pythons and anacondas that are approximately 7.6 meters long. The recently discovered fossil of snake Titanoboa was approximately 15 meters long.
Snakes are thought to have evolved out of their aquatic or aquatic lizard ancestors throughout the Cretaceous period. Modern snakes seemed throughout the Paleocene period. Majority of the species are non-poisonous and the venomous species utilize their venom for a measure of self-defence. Some venomous snakes possess the capability to kill even humans. Non-venomous snakes either swallow the prey living or kill it by constriction. The modern English word snake comes from the Old English word snaca meaning to creep or to creep. Fossil record of snakes is comparatively poor as the skeletons are comparatively small making fossilization hopeless. Fossil records indicate that the snakes have evolved in the burrowing lizards. Primitive snakes among the modern ones would be the pythons as well as the boas.
Snake skeleton is chiefly composed of skull, hyoid, vertebral column, ribs and vestiges of pelvis and hind limbs from the henophidian snakes. Skull is made up of solid braincase to which other bones have been loosely articulated making the jaws flexible so that successful feeding and prey capture can begin. The right and left surfaces of the lower jaw are connected into a ligament whereas the anterior end of lower jaw is articulated with the quadrate making the jaw more portable. Mandibles and quadrate also help in picking sound borne vibrations. Hyoid is a small bone located in the neck region serving for the attachment of the tongue muscles. Vertebral column contains 200-400 vertebrae. Tail vertebrae fewer and lack ribs. Vertebrae of body bear two ribs. Vertebrae have powerful articulation with muscles to be able to bring about effective locomotion in lack of limbs. Autotomy is absent in rodents. Pythons and boas possess a set of vestiges of hind limbs in the form of pelvic spurs present on both sides of the cloaca made up of the vestiges of ilium and femur.
Heart can move out of its location as diaphragm is absent. This house protects heart from damage when large prey ingested passes through the oesophagus. Spleen is found attached to gall bladder and pancreas and aids in blood flow. Thymus is situated just above heart and also is accountable for the generation of immune cells. Cardiovascular method of snakes is exceptional in using a renal portal system where the blood from snake’s tail passes through kidneys before returning back to heart. Damaged lung is vestigial and is even absent in some species. Nearly all species just 1 lung is functional. Anterior portion of lung is highly vascularized engaging in gaseous market while the posterior section fails to do so. Saccular lung provides buoyancy to snake’s body. Lymph nodes are absent.
Skin care is covered by overlapping scales. Belly scales are used for gripping on the surface. Eyelids are transparent and are frequently called brille. Shedding of scales is known as as ecdysis. In snakes that the outer layer of skin is shed as a single layer. Scales are actually the derivatives of epidermis. Scales on head, belly and back are important from taxonomic point of view. Scales are named on the basis of the status in the body. Moulting is very important in snakes it serves two fold purposes. First it enables the snake from worn and old skin and second it will help to eliminate fleas and parasites. Shedding of skin from the form of moulting helps to grow in size and it occurs periodically. Before moulting a snake stops feeding and hides itself in protective places like underground burrows. Before moulting skin becomes tough, dry and eyes become muddy. Inner surface of epidermis liquefies helping the old skin to readily leave the body. Old skin breaks close to the mouth and the snake pushes itself against the face and the old skin leaves the entire body in 1 layer. An older snake sheds its skin once or twice a year. A younger growing snake may lose its skin four times a year so as to grow. Discarded skin gives an imprint of scale structure on the snake’s body and helps in identification.
Snake vision varies considerably. They can only distinguish light and dark objects and the vision isn’t sharp but adequate so they can only trace motions. Vision is greatest in arboreal snakes but poor from the burrow dwellers. Asian vine snake includes a binocular vision so both the eyes can focus on precisely the exact same point. Most snakes focus objects by forward and back motion of lens in relation to the retina while in others lens is elongated. Smell is used by rodents in prey monitoring. Forked tongues assist in olfaction as well as tasting prey. Tongues are stored in continuous movement and allergens from air, ground and water are used for prey capture. The part of bodyin contact with ground is very sensitive to vibrations so they can feel any animal approaching near even with quite faint vibration.
Cobras, vipers and a few related ones utilize venom in order to immobilize or kill prey. Certain birds, mammals and some snakes like the kingsnakes prey on venomous snakes and also have developed immunity as well as immunity against the snake venom. Snake venom is a intricate combination of proteins saved in poison glands at the back of the head. These glands open into hollow fangs which act as hypodermic needles for injecting the venom into the victim’s entire body. The venom proteins may be a mixture of neurotoxins, haemotoxins, cytotoxins and bungarotoxins along with other toxins. Venom has hyalouronidase enzyme which helps in rapid diffusion of venom from the sufferer’s body. Cobras and kraits possess proteroglyphous fangs that remain permanently erect. The next family is Colubridae enclosing boomslangs, tree snakes, vine snakes but all colubrids aren’t poisonous.
All snakes are strictly carnivorous feeding on eggs, fish, insects, small snakes and mammals. They consume the prey as a whole. Poisonous snakes kill the victim with venom before swallowing it other consume the prey by constriction. After feeding they are dormant for successful digestion to take place. They are ectothermic so the external temperature can help in digestion. Best temperature for digestion is 30C. Digestive enzymes help in the digestion of claws, nails, feathers and hairs. Although the limbs have been absent but snakes have developed unique approaches to perform locomotion. Lateral undulation is the most common manner of locomotion performed by both aquatic and terrestrial snakes. In lateral undulation the body of snake flexes to left and right leading to the formation of rearward moving waves. The snake moves faster and high quantity of energy is required to carry out this style of locomotion.
Terrestrial lateral undulation is the most common manner of locomotion performed by property snakes. The posteriorly moving waves push the body more nearer to the touch points in the environment like the trees, rocks etc. resulting in the formation of a forward thrust. Snake moves quicker even in thick or dense vegetation. While swimming the waves become longer and the snake moves quicker. Thrust is generated by pushing the body against water. Sea snakes can perform reverse lateral undulation. Side winding is just another mode of locomotion adopted by colubrids such as vipers, elapids while going on a slick sand flat or sand dune. It’s a modified type of lateral undulation where all of the body sections move in one direction and have been in touch with the floor while other segments are lifted up leading to rolling of human anatomy. This mode of locomotion helps in preserving the energy.
When the push-points are absent and the spider is not able to carry out lateral undulation in addition to sidewinding like from the tunnels as well as the burrows then it moves via concertina locomotion. Inside this locomotion snake dentures that the upper portion of body against the tube wall while the front of mind expands and straightens. Front part is then relaxed and it stinks to shape a anchor along with the posterior portion now straightens and is pulled forward. This is a very manner of locomotion and demands high amount of energy. The slowest mode of locomotion is that the rectilinear locomotion and it is the only mode of locomotion in which the snake does not bends its body. The stomach scales are raised up and pulled forward prior to being placed down and the entire body is pulled over them. Ribs do not move in this manner of locomotion. It’s by far the most usual mode of locomotion in pythons, boas and vipers.
The tree snakes perform locomotion differently that is very much dependent on the bark of this tree as well as on the species. Snakes utilize altered kind of concertina locomotion and might also creep by lateral undulation of touch points can be found. Snakes move quicker on small branches if contact points are available. Fertilization in snakes is internal and is carried by way of hemipenes stored and inverted in the tail of man snake. Most species are oviparous. Ladies of King cobra build nests for their eggs and guard them until they hatch. Many pythons coil round their eggs until they hatch. Boa constrictor and green anaconda are viviparous nourishing the youngs by way of placentas well as yolk sac such as the higher placental mammals.
Snakes in general avoid biting humans. The bite of these non-poisonous snakes is generally benign. Out of the 725 species of venomous snakes just 250 species endure the potential to kill individuals in one bite. Australia averages only one deadly snake bite annually. In India about 250,000 deaths have been recorded in a year by snake bite. Bite of a poisonous snake affects every organ of human body. It causes dizziness, fainting, increased appetite and head ache. Blood pressure gets low and pulse rate increases. Respiration slows down. Excessive bleeding occurs at the website of the bite. The snake venom can be treated with the help of anti-venom. Antivenom is species specific and is prepared by collecting the venom from the poison gland of these poisonous snakes and is then injected into the body of horse. The doses of venom are raised in the future till the horse is immunized. Blood is extracted in the immunized horse along with the serum is separated and processed and is allowed to freeze.
In this show the Pest Experts plays music and the spider is seen to perform specific sorts of motions which are actually a kind of defensive action in response to the motions of this flute. According to the Wildlife Protection Act of 1972 has prohibited such types of illegitimate acts. Snakes are also consumed as food in some specific parts of world. In China, Thailand, Taiwan drinking the blood of snakes is thought to increase the sexual virility. Snakes are also a famous delicacy in the form of snake soups in certain Asian countries. In western world snakes are also reared as pets. They also deserve a special place in the history and religion. Brazil is known as the Snake Island since it houses the largest population of snakes.
Though snakes appear dangerous but they help in maintaining the environmental balance.