Reptile's

What is an reptile:

 A cold-blooded vertebrate of a class that includes snake, lizards, crocodiles, turtles, and tortoises.

They have a dry scaly skin, and typically laying soft-shelled eggs on land.

Characteristics and Definition  of Reptiles

• Reptiles cannot regulate their body temperature and have to rely on external sources to control their body temperature = heating up by lying in the sun, or cooling down by moving into shade or water.

• They can stay without food for extended periods, especially with cold temperature.

Snake movement

Concertina movement
 
This form of movement leaves a different set of tracks altogether. This form of motion involves the snake pulling up the body into bends and then straightening out the bends. It is called concertina after the instrument, and this motion has a very similar quality of  movement, and this motion has a very similar quality of movement to a concertina or according contracting and expanding. This from of locomotion is most efficient or when climbing. Mostly used by tree living snakes e.g. Boomslang.

Side-winder motions

This form is used by many types of snakes when crawling over smooth, slippery or unstable surfaces.  The snakes best known for this kind of motion are the Middle-eastern and North African vipers species that live in areas of extensive sand. In this motion, the  snake  sends  a wave down the body such that the body rolls from head to tail and portions of it are lifted off the ground as the body moves. The track is relatively proportionate to the length of the snake. This is one of the more efficient methods of movement over loose sand, especially for shorter, heavier bodied serpent.

S-Curved Motion/Lateral Undulations

This is a normal swimming motion over the ground and is common with most slender land dwelling snakes. As they come in contact with an object- such as a stick, plant stem, stone or piece of uneven ground-the part of the body nearest that object exerts, and deforms locally around it. 

Caterpillar motion/Rectilinear

This form of motion leaves snake tracks that are in more or less a straight line. This type of movement is used mostly by larger and heavier bodies snakes . It is used especially in areas of relatively open ground. In this motion, the snake uses its belly scales as the main source of traction. It moves by first lifting the belly scales slightly from the ground and pulling them forward, and then pulling them downward and backward. This movement is similar in appearance to the slow, flowing walk of a caterpillar. In this movement, the tracks are most likely to show the belly scales clearly.

 Venom

To most people venom and snakes go hand in hand. It is commonly believed that all snakes are venomous, but this is an erroneous belief. Of the 2.700 known species of snake only 300 are venomous.

So what is venom, how did snakes get it and why do they have it? These are questions that have interested herpetologists and other scientists alike.

Venom itself is a poison secreted by animals for either defensive or offensive purposes. Venom originated from digestive enzymes that were originally located in the stomach. Throughout the millions of years it has progressed quite a lot and in some animals has become quite different from it's origin.

The type of venom depends on the type of animal. In spiders venom is kept rather simple. It is pretty much just digestive enzymes. Spiders use their venom to turn their hard shelled insect meals into nice and nutritious goo. So in a sense one can think of this type of venom as a form of starting the digestive process before you even start to eat the meal.

In insects venom is used predominantly as a defensive weapon. Wasps, bees and ants use formic acid in their stings to cause a painful burning sensation that will either kill or injure their enemy enough to make them think twice about attacking them again.

Amphibians all use their venom for defense. In amphibians the venom is secreted through glands in the skin to make the animals unpalatable.

So as we can see venom is a predominantly defensive adaptation. An adaptation that has found it's way into every class of vertebrates except one. The birds; the only class to forego any venom.

In mammals we have platypi with venomous claws, then there are the fish which comprise too many venomous species to count and finally we have the reptiles.

All venomous reptiles are squamates and of them snakes make up the bulk. There are only two species of venomous squamates that are not snakes, the lizards of the genus: Heloderma. These lizards use their venom for defense as well and can deliver powerful and painful bites.

In snakes venom has found a new use, for offense. Since snake prey generally has the advantage of speed (not to say that snakes can't be speedy. A black mamba traveling at 17 mph is nothing to sneeze at.) snakes had to find a new way to take down their prey without running the risk of losing them or getting too hurt in the process. Enter venom, a fast and effective mode of subdueing prey items with minimal risk to the snake.

Venom types

Snake venom can be divided into two broad (yet fuzzy) categories. That of hemotoxicity and neurotoxicity.

Hemotoxic venom effects the blood and organs, causing a breakdown or inflammation in the body. Hemotoxic bites are the most painful as breathing hurts and tissues start to die.

Neurotoxic venom, as the name suggests, effect the nervous system, leading to everything from siezures to death. Neurotoxic bites are the most deadly.

Although we have these two wonderful different categories, no snake fits completely in each. Many snakes incorporate both neurotoxic and hemotoxic venom in their bites so when telling them apart one goes by which type is more predominant. 

Type of snake ( fangs:

Burrowing snakes:       diversity of fangs, erectile fangs

Typical snakes:   include two groups, non venomous and venomous

·        Solid toothed non venomous include mole snake, water  snake etc

·        Back fanged such as boom slang and vine snake

Adders:      short, short stocky snakes with short tails and their fangs hinge forward and males tend to flight during mating season. Erectile front fangs.

Cobras &Mambas:       The family Elapidae and the rRhinkals has the habit of plying dead as form of protection. Fixed front fangs.

Do all Reptiles Hibernate?

With some reptiles, such as box turtles, hibernation is an important part of their lifestyle while for others, such as garter snakes, it will depend on the circumstances, such as whether any breeding is planned. Of course, in many instances, you will not get any choice as the reptile will decide for itself! You will notice it becoming more inactive and losing interest in food as autumn progresses – this is usually triggered by a change in temperature, length of day or light levels.

In many reptiles, the cooling period stimulates the production of sperm in the males and ovulation in the females – thus, hibernation is necessary for breeding. It is often useful in re-setting the reptiles internal clock and encouraging it to eat again. Box turtles are perhaps the first to spring to mind when thinking of pet reptiles that hibernate although reptiles from many different ecosystems will enter a state of hibernation at low temperatures. These include desert tortoises, temperate tortoises (including box turtles), aquatic turtles and most snakes from temperate zones, such as king snakes, milk snakes, water snakes, bull snakes and garter snakes.