Reptile Species

Reptile species can be found throughout the world. They’re usually fairly easy to identify, especially the Squamata (lizards and snakes). The chameleon is another favourite. Its ability to change colour allows it to mimic its surroundings or assert its dominance.


Like all ectotherms, reptiles use the environment to regulate body temperature. This includes behaviours such as basking in sunny places or seeking shady spots.

Body Structure

Reptiles are the dominant terrestrial vertebrates and can be found worldwide. They are characterized by dry, scaly skin and are mostly cold-blooded (ectothermic). Most reptiles lay eggs, while a few, such as the boa constrictor, give birth to live young. They are a class of vertebrates that has evolved from the Amphibians and are now considered to be the dominant terrestrial tetrapods.

The earliest true reptiles, called Anapsida, appeared in the fossil record about 300 million years ago and were characterized by solid skulls with no temporal fenestrae—holes for the nose, eyes, and spinal cord. Eventually, one branch of the Anapsida evolved into living diapsids, including turtles and crocodilians, while another developed the jaw muscle attachment holes called temporal fenestrae in their skulls and became today’s snakes, lizards, and birds.

All modern reptiles are ectotherms, meaning that they do not generate body heat through metabolism and depend on external sources to regulate their temperature. They do this through behavioral adaptations, such as basking in the sun to warm up or seeking shady spots or going underground to cool down.

A characteristic feature of the reptile body is a dorsal fin, which is located on the back of the body. This fin is used to assist in swimming by generating thrust against the water and providing ballast for stability. Most reptiles have closed circulation with a three-chamber heart that is divided into two atria and a single, variably-partitioned ventricle. This enables the animal to control blood flow and shunt deoxygenated blood away from the lungs during respiration.


Reptiles have adapted to many types of habitat. Most are terrestrial and live in forests, grasslands or deserts; others are semi-aquatic and forage in lakes, rivers and wetlands. Some, such as the wood turtle and Eastern Box Turtle, are completely terrestrial, while others, including the Veiled Chameleon, spend most of their lives in trees and shrubs.

As ectotherms (cold-blooded animals), reptiles are unable to regulate their body temperature independently of the environment, so they must seek out warm or cool areas to control their internal temperatures. They have thick scaly skin, which helps them conserve heat and prevents water loss from their bodies. In hot conditions, they may bask in the sun to warm up; when it is cold, they search out shade or a cool spot to stay comfortable. Some reptiles can enter a state of torpor or brumation, which is similar to hibernating, to survive extreme cold temperatures.

Unlike birds, mammals and amphibians, most reptiles cannot fly, but some tropical snakes and lizards can glide from tall trees by flattening their bodies and falling slowly to the ground. Like amphibians, reptiles have lungs to breathe air; they also have hard bony skeletons and a wide range of adaptations for moving around their habitats. For example, some lizards walk by pushing their belly scales against rough surfaces to gain momentum and move forward; alligators, coyotes, crocodiles and certain snake species use their tails for propulsion when swimming; and sea turtles swim by using flippers or by sweeping their heads from side to side.


As a reptile owner it is vital to know the feeding habits of your reptile. It is important that you can distinguish if your pet is Herbivorous, Omnivore or Carnivorous (meat eating). Reptiles fed an improper diet will experience nutritional imbalances which lead to illness.

Herbivorous reptiles need fresh, leafy green vegetables such as collard or kale, mustard greens, turnips, radish, green peas and dandelions and squashes such as pumpkin and zucchini. Non-citrus fruits can also be offered. These should be fed daily for juveniles and bi-weekly for adults. They may need to be lightly steamed in order to soften the vegetable and allow better absorption of nutrients.

Omnivorous reptiles need a mixture of vegetable, fruit and insect prey. The amount of each will vary by species. For example, bearded dragons start out as insectivores and gradually become omnivorous. These reptiles need a diet that is 60% invertebrates (mealworms, crickets, wood cockroaches and wax worms) and 40% vegetables and 20% fruits.

Insect prey needs to be thoroughly rinsed in hot water before feeding in order to remove any bacteria that could potentially transfer from the hands to the reptile or from predators to prey. This is especially important for arboreal and sylvian species that may have difficulty reaching their food. Whenever possible, try to raise your own insects for feeding to reptiles. This is less expensive than purchasing prey items and will provide you with a constant supply of healthy, vitamin-supplemented insects that are ready to be fed at a moment’s notice to your reptile.


Reptiles have a number of unique breeding habits. The majority of them are oviparous, meaning that they lay eggs that hatch outside their bodies. In these cases, sperm is inserted directly into the eggs by the male’s single penis or one of his two hemipenes. A cloaca in the female’s abdomen houses these organs and acts as an external incubator for the eggs. Once a clutch is fertilized, the resulting embryos can be stored for up to six years before they need to be fertilized again.

Many reptiles also reproduce asexually. This process is called parthenogenesis and it occurs in lizards and snakes that are able to produce unisexual diploid clones of themselves. Interestingly, these asexual offspring have the same genetic characteristics as the parental clones and therefore, as in mammals, are vulnerable to hereditary diseases.

For many species of reptile, reproduction is a time of courtship and territorial displays. Males will change color to display their breeding coloration and may display by head nodding, bobbing or flashing of the skin (known as dewlapping). This is especially true for sand lizards such as Britain’s rare Lacerta agilis, where males discard their year-round brown colouration in favour of a distinctive green at breeding time. They also release pheromones to attract potential females. It is important that pet owners understand the mating rituals, breeding processes and health problems associated with their particular species. Recognizing abnormal behavior can alert the caretaker and veterinary practitioner to a potential problem before it progresses to serious consequences.