There are over 3000 species of snakes around the globe with at least one distinct species in every continent. As much as snakes have always had a bad reputation especially as a pet, they often can be quite helpful and a fun pet.
Snakes belong to the reptile group and are characterized by lack of limbs, urinary bladder, eyelids, sternum and ear openings.
They have an elongated body and narrow with all its body organs fitting into the narrow structure.
Do snakes have necks?
The most unique aspect of a snake is its elongated body, tail and the absence of limbs. Snakes do not have necks instead they simply have a slender elongated body and a tail at the end.
There are no species of snake that has retained limb ruminants for its locomotive functions.
Some of them have complete or reduced elements of femur and pelvis as evident in some families of snakes such as boa and python.
The bodies of snakes are usually slender compared to other animals, however, among the species of snakes, there are those which are thin and others thick.
The thin this species of snakes are known to move around all the time while the thick species are known to sedentary in life.
Did snakes lose their necks?
For a very long time, it has been thought that snakes did lose some of the regions in their body such as their neck during evolution from their four-legged ancestor into their sinuous shape.
However, looking at their subtle difference in the shape of a snake’s vertebrae sheds light on the evolution of the creatures.
Contrary to belief, snakes do not lose part of their body, instead, mammals and birds gained independently most parts of their body.
Hox genes which are responsible for the development of the neck, tail and lumbar region in lizards, birds, crocodiles, and mammals are believed to have been disrupted in snakes which resulted in the formation of the elongated legless shape.
Snakes are very different from other amniote groups that descended from the four-limbed animals that have backbones and lay eggs since they lack the forelimbs, shoulder girdles, and sternal skeletons.
Researchers have been able that the establishment that the evolution of the snakes was not driven by the simplification or loss of the hoax genes. They believe that it would result in fewer regional differences in the shapes of vertebrae.
Instead, it is the exact opposite since snakes possess the same number of regions in their vertebral column as limbed lizards.
During the evolution of the snakes, the hoax genes control more subtle graded changes in shape instead of patterning distinct rib-less regions in the neck.
The vertebral column of snakes is elongated and has more vertebrae than any other living animal.
They do not have limb girdles that are associated with the skeleton. Hence, snakes are regarded to have only two kinds of vertebrae that is the body and the tail.
In the entire body of a snakes, there are between 100-450 vertebrae while in the tail there are between 10-205 vertebrae.
The body vertebrae are paired with ribs except with regions around the neck.
On the tail side, there are no rib vertebrae. Each vertebra articulates itself at five different points.
The five points of articulation allow for vertical and lateral rotation hence preventing twisting of the vertebral column thus enhancing both rigidity and flexibility.
Snakes are usually covered with scales which are simply cornified folds in the epidermal layer of the skin.
The scales are usually arranged in rows along the entire body of the snake’s skin.
The scales are usually arranged in rows and the numbers, as well as the arrangements of which, are characteristic of the species.
A single scale may be very smooth and shiny and have a raised ridge in its center.
Some sensory snakes have sensory structures on the posterior margins called apical pits. Other than this, they also have scales in various micro-ornamentations.
The scales on the ventral surface are modified into broad plates and a majority of the species use it for locomotion.
On the ventral surface of blind snakes, sea snakes and worm snakes are partly enlarged ventral scales.
The colors and patterns that are seen in snakes are often bright and spectacular. They are produced in two different ways.
The colors are produced from the pigment that is deposited in the skin or rather through differential diffraction of light as a consequence of the physical properties itself.
When the skin of the snake is seen on a unicolor or a uniform background then their color patterns seem very obvious and prominent.
The significance of their natural colors become relevant when they are in their natural habitat.
Spotted or blotched snakes tend to be heavy-bodied and sedentary while striped and the occasional unicolor snakes are active species.
Snakes generally use the color of their skin for protection. In that coiled sedentary snakes have their body completely outlined by overlapping patterns.
On the other hand, the stripes on crawling snakes eliminate the sensation of motion until they disappear.
Snakes also use their colors to hide.
However, there are certain types of species that rather seem to be advertising themselves rather than trying to hide.
The patterns on the skin of the snakes are a warning sign to the enemies and predators that they run the risk of a horrifying encounter with the snakes.
On the contrary, there is no evidence of aposematic instinct as naïve predators attempt to prey on the snakes.
The sense organs of snakes are very unique and different from those of mammals.
Mammals mainly rely on the aspect of sense and hearing while snakes basically rely on the sense of touch and smell.
Unlike mammals’ snakes do not have moveable eyelids instead they have protective eye covering known as brille.
This makes their movement fairly limited. Snakes do not have an external ear, middle ear or tympanic membrane.
Snakes make use of small ossicle known as the lamella to detect sound vibrations that are conducted through the ground. They are also able to conduct sound waves that are passed through the air at a very low frequency.
Snakes have a distinct kind of smelling technique that is very different from mammals.
Snakes have nostrils and nasal cavities however they do not use them for smelling. Snakes make use of a flicking tongue as a smelling device.
The flicking tongue basically brings minute particles into contact with vomeronasal.
It is a small organ on the roof of the oral cavity and the snake then perceives and identifies the prey as a small predator or prey.
Snakes possess a sixth sense which cannot be found in any other reptile or mammal. Rattlesnakes, vipers and other members of the family of snakes have pits that are located in between their eyes.
The pits are used to sense very small temperature changes inform of infrared rays.
This aids in locating warm-blooded animals such as rodents.
The pit has two chambers that serve different functions.
The interior chamber measures the internal temperature of the snake. In addition, the exterior chamber measures the external temperature of the snake.
The exterior chamber heats up when its close to an external source. Hence, the snake is able to detect the temperature difference.
It is a very accurate system in that the snake is able to detect very minute temperature changes as low as 0.002 degrees Celsius.
Snakes just like all other reptiles are covered with scales which s a protective covering from dehydration and abrasion.
The scales that are on top of the body of the snake are thinner and smaller than those found on the belly side.
Scales that are found on the bottom side help to protect and support the tissue that is in contact with the ground. They are very colorful and are organized into interesting patterns.
It is very hard to know the difference between a male and a female as they look very similar externally. Snakes are usually described as being slimy though their skin is very dry.
Snakes grow continually for a very long time until they die.
They shade their skin periodically in a process known as ecdysis. The period before they shade their skin snakes take their slightly bluish hue eyes and tend to appear very cloudy.
This is a result of a fluid that is located between the layers of the skin.
Want to find what snakes are afraid of? Find it out here.
Other important facts about snakes
Snakes differ depending on the type of teeth that they possess and this determines the technique they use to capture the prey.
There are snakes that use hollow fanged, groove fanged or constrictors.
The skin of the snake is often shade in one piece including the brille exception of the rattle.
The rattle of the snake is retained as the snake grows and a new segment is added every time the snake grows.
In some parts of the world, it is assumed that the rattle segment is used to indicate the age of the snake.
Musculature and locomotion
Snakes utilize their internal body muscles for locomotion. When it comes to movements there are four basic types.
Lateral progression is a type of movement that entails undulating crawling often referred to as slithering and it allows the snake to reach maximum speed.
Rectilinear movement is a type of movement where large and heavy snakes use caterpillar movement to travel in a straight line.
This kind of movement entails the snake moving the belly of the skin forward and then pull the rest of the body along with it. Sidewinding is a type of locomotive movement where the snake hurls the body in a sideways looping motion.
It is mostly used by snakes that live in the desert. Some snakes apply concertina technique when climbing trees.
The body of the snake bunches in a horizontal moving loop then move the head forward and then straighten the body.
The respiratory system of snakes includes the lungs, trachea, bronchi and air sac.
The trachea originates from the glottis at the back of the oral cavity and ends near the heart where it branches into the bronchi.
The bronchus on the left leads into the left lung which is simply a reduced vestigial. They are very small, degenerate and non-functioning.
The bronchus on the right leads to the right lung and is elongated.
The anterior portion of the lungs is vascular and functions in the exchange of gas while the second half of the lung is vascular air sac that extends to the tail region.
The digestive system of snakes is composed of the stomach, colon, esophagus, colon, and glands.
The esophagus runs adjacent to the air sac from the throat through to the stomach.
Unlike mammals, the esophagus of the snake is very little and food is moved to the stomach through the movement of the entire body.
The junction between the esophagus and the stomach is never well defined and the stomach itself is not well balanced.
They also have very small intestines which are relatively simple.
The atria and ventricles make up a three-chambered heart of a snake. The right and left atria receive blood from the body and the lungs respectively and pass it out through the ventricles so that they can be circulated again.
The spleen is attached to the gall bladder of the pancreas and its main function is to filter the blood and recycle the red blood cells.
The endocrine system is made of glands that secrete hormones. These glands are essential for normal functioning.
They also have an endocrine system that is very similar to that of mammals. For instance, they have thyroid and adrenal glands.
The thyroid glands are responsible for growth and development while the adrenal glands are responsible for respiration.
In summary, the structure and body of a snake are very unique and unlike other animals, they do not have a distinct neck.
Check out our guide on what do baby snakes eat by clicking here.