Reptiles are one of the oldest evolutionary groups of vertebrates. They are descendants of fish and amphibians, while today's birds and mammals come from the reptile branch. They owe their name "Reptiles" to their crawling movement on the ground. Although most people believe that reptiles live only on the ground and hide in rock crevices and under stones, there are several groups that live either on trees or in the sea.

Temperature regulation

Reptiles are ectothermic animals, meaning they cannot regulate their body temperature through internal metabolic processes. However, they have the ability to regulate their temperature through their behavior, utilizing the heat of solar radiation and the various thermal microenvironments in the areas where they are found.

Skin

The body of reptiles is covered with scales (scales) made of a substance called keratin. The scales constitute the dry, soft outer part of the skin and their main property is to prevent water loss from the body. Reptiles owe their various colors to pigment cells located just below the scales. The colors of the different species are the result of adaptation to each lifestyle and behavior.

Reptiles shed their outer skin several times during their active season in a process called "ecdysis." This layer is replaced by a new, healthier layer. In snakes, this outer layer is shed in one piece, while in lizards and turtles, it is shed in sections.

Respiration and circulation

They breathe through well-developed lungs, and their circulatory system consists of arteries, veins, and a three-chambered heart (two atria and one ventricle).

Limbs and movement

Turtles and most lizards have well-developed limbs (hands and feet) with curved claws on their fingers, while in snakes the limbs are absent. Some lizards also have no limbs and are called legless lizards, while there are also lizards whose limbs are disproportionately small compared to the rest of the body. These lizards are not so fast and their body movement resembles the movement of snakes.

Reptiles, due to their exothermic nature, do not need to absorb large amounts of energy through their diet to live (unlike birds and mammals that), while special adaptations of their physiology prevent water loss. These characteristics have enabled reptiles to colonize even the most arid parts of the planet. They feed on small amounts of food (small insects, frogs, other reptiles, birds and small mammals) and are one of the most important links in the food chain of ecosystems.

This is a group of the order of the scaly lizards with a wide distribution as it is found on all continents except Antarctica and even in places with very low temperatures. The group of lizards includes more than 6,000 different species. The group of lizards bears several similarities to snakes (as they are in the same evolutionary order) but differs from them mainly in that lizards have four well-formed limbs (legs) and an external ear.

In Cyprus, 11 species of lizards are found which are divided into 5 families, (a) the crocodiles with one representative, (b) the chameleons with one representative, (c) the samiamids with two representatives, (d) the common lizards with three representatives and (e) the liacones with four representatives. Of the lizards on the island, the largest are the Kourkoutas and the Evmikis with a length that can reach half a meter (50cm)

All species of lizards are protected by the Bern Convention while most of them are also protected by national legislation [Law 153(I)2003] and the European Directive 92/45/EC. Particularly important is the Ammosaura which is strictly protected and has been declared endangered by the International Union for Conservation of Nature (IUCN).

Skin

The body of lizards, like snakes, is covered by scales which protect the animal in various ways. A particularly important property of the skin is its tightness which prevents water loss through it, a fact that allows lizards to colonize arid areas. Lizards, like snakes, shed their skin periodically through a process called molting. Unlike snakes, lizards' skin is not shed in one piece, but in sections.

Smell

Lizards receive information about the odors of their environment, both through their nostrils and through an organ located in the roof of their mouth called the Jacobson's organ. With the help of their tongue, which they constantly stick out of their mouth, they collect odors (chemical particles) from the air and the ground. When the tongue returns to the mouth, the particles attach to the chemical receptors of the Jacobson's organ, which detects them. This system is extremely sensitive and much better than the sense of smell in humans.

Hearing

Lizards' hearing ability, although better than snakes, is quite limited. In most species, the outer ear is either absent or quite developed, which makes it difficult to perceive sounds through the air. Through the external tympanic membrane and the system of transmitting sounds to the inner ear, lizards can hear low frequencies quite well, while some classes such as the samiamids can hear high frequencies equally well.

Vision

The majority of lizards have very good color vision, which helps them both in detecting movements and in capturing their food, as well as in developing a number of behaviors. These behaviors are based on responding to visual signals through movements and displaying colors in parts of their bodies.

Tail autotomy

Several species of lizards have the ability to cut off their tail (tail autotomy) in an attempt to escape predators. The severed part of the tail makes strong contractions and the predator focuses on it, which gives the lizard enough time to move away to a safe shelter. The severed part of the tail will regenerate over time (a few weeks). It differs from the original part of the tail only in its internal composition as the skeleton within the regenerated tail does not consist of bone tissue but of cartilage.

Families found in Cyprus

FAMILY AGAMIDAE:

This family includes 433 species found in Europe, Australia, Africa and Asia. These are medium-sized diurnal lizards that do not exceed half a meter in length. Although there is great diversity in terms of color and shape among the representatives of this group, the triangular head and the absence of large scales on its upper part are common characteristics to all individuals of this family. Only one representative is found in Cyprus, the Starred  Agama (Kourkoutas).

FAMILY CHAMAELEONIDAE:

This family includes 197 species, most of which are found in Africa and Asia. These are particularly slow-moving, diurnal lizards that have adapted to arboreal living. They have a laterally compressed body, enlarged eyes with independent function, fingers and tail adapted to hold the animal on tree branches, as well as a unique ability to change the color of the skin for easy coverage in vegetation. Only one representative is found in Cyprus, the common Chameleon.

FAMILY GEKKONIDAE:

This family includes 945 species, most of which are found in the tropics. They are small nocturnal species with excellent climbing abilities. These abilities are due to the presence of special formations like suction cups on the fingers of most species, which allow them to climb even the smoothest surfaces. The species of their family have the ability to produce sounds while their skin bears many small bumps. Only two representatives are found in Cyprus, the Turkish Gecko and the Kotschy's Gecko.

FAMILY LACERTIDAE:

This family includes 312 species that are spread across Europe, Asia and Africa. This is the family that was first described and the morphology of its representatives is considered the most "typical" form of lizards. The lacertids are fast lizards, with well-formed limbs and head. They hunt during the day and almost all lay eggs with the exception of a limited number of species that give birth directly to young individuals. In Cyprus, three representatives of this family are found, the Schreiber's fringe-toed Lizard, the snake-eyed Lizard and the Troodos Lizard.

FAMILY SCINCIDAE:

This family includes 1,560 species and is the largest family of lizards. Its representatives are found all over the planet with the exception of the Antarctic continent, while they present an impressive diversity, both in size (from 2 - 35cm), as well as in morphology and behavior. A special characteristic of the family is the underdeveloped limbs, the absence of a distinct neck, the smooth skin surface and the densely arranged overlapping scales. Due to the underdeveloped limbs, the movement of the individuals resembles more the movement of a snake than that of a typical lizard. The limbs are completely absent from some representatives of the family. In Cyprus, four representatives of this family are found: Snake-eyed Skink, Ocellated Skink, Bridled Skink and Schneider's Skink.

This is one of the oldest evolutionary groups of reptiles. It is divided into four families that include almost 300 different species. Their body is surrounded by a protective shell called a "shell" or "carapace". This shell consists of a convex dorsal section (shield) and a flat ventral section (plastron). The shell in several species has the role of armor as both the head and the other limbs of the animal can be withdrawn inside the shell for protection. Like other reptiles, turtles are found on all continents except Antarctica and even in places with very low temperatures. Three species of turtles are found in Cyprus. Two of them are marine and one lives in the fresh water of rivers. All three species are strictly protected by both European Directives and national legislation. In Cyprus, there are no land turtles.

Skin

The body of turtles is also covered with scales, just like snakes and lizards, although it has certain peculiarities. These peculiarities are due to the presence of the scutellum, which consists of two layers of plates. The outer layer is made of keratin while the inner layer is bony. As an individual grows in age and size, new layers of keratin are added under the old ones

Skeleton

The skeleton of turtles is quite different from that of other reptiles, due to the presence of the scutellum. The parts of the dorsal vertebrae and the sides of the animal are joined together with the bony part of the scutellum, composing a single, strong and very stable body.

Hearring

Although they have a middle and inner ear, the perception of sound is quite limited.

Smell - Vision

In contrast to hearing, turtles have a very good sense of smell and acute vision. They even seem to be able to distinguish colors as well as humans.

Diet

Turtles do not have teeth like other reptiles and their mouths resemble more a bird's beak than a lizard's or snake's mouth. Instead of teeth, they have hard horny shells through which they crush their food. They are mostly omnivorous, although there are some species of turtles that are exclusively carnivorous and feed on frogs, fish and any other animal they can catch.

They are legless reptiles with a long, flexible body.

With more than 10 families and more than 2500 species, snakes are a large and evolutionarily successful class of animals. They are found on all continents except Antarctica, even in places with very low temperatures.

In Cyprus, there are eight species of snakes, of which three are poisonous but only one is dangerous to humans. One of the eight species of snakes is endemic to Cyprus (the so-called Cypriot snake) and a second endemic subspecies (the Cypriot water snake).

Skin

The body of snakes, like that of lizards, is covered in scales. Snakes shed the outer part of their skin at a specific time of the year. The old skin is replaced by a new, healthier layer through a process called molting. This process occurs several times a year and its frequency depends mainly on the age of the individual and its growth rate. Unlike lizards, snakes change their skin not gradually and piecemeal but all at once, shedding it like a shirt.

Skeleton

The skeleton of snakes is very light and very flexible. They have a relatively large number of vertebrae, which exceeds one hundred and in some species can reach 400. As a measure of comparison, humans have only 32 vertebrae. This characteristic, combined with the muscles located between the vertebrae, makes snakes very flexible animals.

The anatomy of the skull of snakes has special adaptations. The bones that make up the jaw of snakes are not adapted to the skull. Instead, they are connected, both to each other and to the skull through elastic tissues and muscles. This connection gives the jaws of snakes extraordinary flexibility, which allows snakes to eat animals much larger than their heads.

Smell

Snakes receive information about the odors of the environment, both through their nostrils and through an organ located in the roof of their mouth called the Jacobson's organ. With the help of their tongue, which they constantly stick out of their mouth, they collect odors (particles of chemical substances) from the air and the ground. When the tongue returns to the mouth, the particles attach to the chemical receptors of the Jacobson's organ, which detects them. This system is extremely sensitive and much better than the sense of smell in humans.

Hearing

Snakes do not have external auditory organs (ears). However, they have a system of sound transmission and recognition that consists of small bones inside the skull. This system allows them to hear low-frequency sounds and feel vibrations that travel through the ground or water.

Vision

The majority of snakes have very good vision, which helps them especially in detecting moving objects. However, there are some groups that live underground and that can only distinguish fluctuations in light.

Venom

Many species of snakes inject venom into their prey through appropriate formations on their front or back teeth. Most venomous snakes bite their prey and wait for the venom to take effect before swallowing it whole. The venom is produced in glands on the back of the sides of the head (parotid glands) and contains a combination of poisonous substances. Some of them paralyze the nervous system while others break down body tissues so that the prey is digested before it even reaches the stomach.

Families found in Cyprus.

FAMILY TYPHLOPIDAE:

The blind snakes are a family of about 260 members divided into six genera and are often found in tropical areas. Their appearance is reminiscent of earthworms due to their small size (often under 15cm), and their very small eyes which are only able to distinguish the presence or absence of light. They are usually black, brown or pink in color and the tip of their snout which protrudes is used as a shovel for digging burrows. They spend most of their time underground and rarely appear above ground. The only species of the family found in Cyprus is the Worm Snake.

FAMILY COLUBRIDAE:

The family of colubridae is diverse and paraphyletic, as it includes snakes that do not have enough characteristics to be included in other groups. With few exceptions, the family consists of non-venomous or Opisthoglyphous snakes that are harmless to humans. Six of the eight snakes of Cyprus belong to this family: the Coin Snake, the Black Whip Snake, the Cyprus grass snake, the Cyprus snake, the Cat Snake and the Montpellier Snake.

FAMILY VIPERIDAE:

The family Viperidae consists of approximately 330 species distributed in Europe, Africa and America. Most of the species of the family are oviparous although cases of egg-laying have been observed. The species are characterized by their large fangs, which fold into the palate when the snake is not using them. They usually rely on camouflage to hunt and often do not move when a person approaches them, resulting in their bite. Blunt nosed Viper is the only representative of the family in Cyprus and the only species that is dangerous to humans.

Although amphibians are not part of the reptile group, they are usually examined and studied alongside them.

Evolutionarily, they are placed between fish and the rest of the terrestrial vertebrates and are characterized by their peculiarity of spending part of their lives in a wet environment (in the early stages of their development) and part of it in a dry environment. To this peculiarity they owe their name (amphibia) which comes from the Greek words "amphi" which means between two places and "bio" which means life.

In the world today, approximately 7,000 amphibians have been recognized, which are divided into 3 large groups. These groups are (a) the urodeles which are animals with well-developed limbs and tail (e.g. salamanders), (b) the anuras which constitute the largest of the three groups and which although have developed limbs, do not have a tail (frogs) and (c) the apodes which do not have limbs (a small number of representatives).

In Cyprus, only three species of anuran amphibians are found in areas with abundant or limited water.

Skin

The skin of amphibians is very different from that of reptiles. It is not covered by scales or other external formations but is thin and soft and bears a multitude of glands. These glands secrete substances which help maintain moisture and the body's defense. These substances are responsible for the slippery texture of their skin.

Skeleton

Amphibians have typical bony tissue with light hollow bones. Most amphibians have four digits on their forelimbs (hands) and five digits on their hind limbs (feet) and, unlike reptiles, they do not have claws on their toes. In anuran amphibians, the hind limbs are larger and stronger than the front limbs as these individuals move by jumping.

Hearing

Hearing in anuran is highly developed but lags significantly behind in urodeles. Anuran does not have an external ear but a large tympanic membrane which, with the help of a system of bones, transfers sound vibrations to the inside. Through this system, anuran are able to distinguish high-frequency sounds through which they can distinguish individuals of their species and locate a mate during the mating season.

Vision

Most species of amphibians have very good vision, both in light and in the dark. The eyes of amphibians are clearly more complex and improved than those of invertebrates and are the first step towards the appearance of more developed eyes in vertebrates. Through them, they can distinguish various wavelengths as well as perceive depth of field.

Reproduction

Amphibians reproduce through external fertilization, which occurs in an aquatic environment. Even species that show a high degree of independence from water, return to lakes and reservoirs to mate. The female lays several hundred eggs in the water, which the male sprinkles with his sperm. The eggs hatch into tadpoles, which are directly dependent on water. Upon reaching adulthood, the tadpoles transform into perfect individuals that can emerge and move away from the water.

Poison

Many amphibians secrete venom from their epidermal glands to protect themselves from predators. In some South American species, this venom is very potent and can even cause death.

Families found in Cyprus.

FAMILY HYLIDAE:

The tree frog family has demonstrated great evolutionary success with 870 species divided into 50 genera. Most, as the name of the family suggests, are arboreal, but some are terrestrial or semi-aquatic. They are characterized by bulging eyes that provide binocular vision and by the "pads" on their feet. Their limbs are usually long, for ease of climbing on smooth surfaces. In Cyprus, the only species found is the Tree Frog.

FAMILY RANIDAE:

The species of the Ranidae family are also called "True Frogs" due to their typical appearance. They are the most widespread family of anuran worldwide with approximately 315 species spread across all continents except Antarctica. They are usually small in size (4-8cm) and have smooth and moist skin, muscular legs and membranes between the toes of their hind legs. In Cyprus, only one representative of the family occurs, the Cyprus Marsh Frog.

FAMILY BUFONIDAE:

The family of "True Toads" includes 500 species on all continents except Antarctica and Australia. They are characterized by their dry and bumpy skin and their overall inflatable body. Behind their eyes, bumps are observed, which are salivary glands, the produced substance of which is sometimes toxic. On the island of Cyprus, the Green Toad occurs.