INDIAN CHAMELEON
(Chameleo zeylanicus)
CHAMELEONS are a unique group of lizards. Their closest relatives are
Iguanas and Dragon lizards (Agamidae). Chameleon means “Earth Lion”. Some Iguanas living in America are called
FALSE CHAMELEON, due to their ability to change colours and other resembling
traits.
About 156 species of CHAMELEONS ARE CONCENTRATED IN Africa , Madagascar
and neighbouring area. Just one species has been recorded in Europe and Indian
subcontinent including Srilanka.
They are characterised by :
1.A long extendable tongue
2. Watch spring like (Prehensile) tail,
3. Protruding but independently movable eyes.
3. They have the ability t change colours depending on
its moods and environment around.
The limbs of Chameleons are long and thin. This helps it to carry its
body high.
Most of the chameleons are tree dwelling ones. Their forelimbs have
bundled toes, with two toes on the outside and three toes on inside; their hind
legs have two toes inside and three toes outside. These combinations of toes
have changed each limb into a pair of clasping tongs for the chameleon to have
a firm grip on its perch.
In addition to these limbs they have a PREHENSILE TAIL (Grasping tail),
resembling watch spring, that helps it to balance its body weight if need be.
Africa is the home of these lizards. They are mostly found in Africa,
south of Sahara , Madagascar. But the common Chameleon , Chameleon vulgaris , is an inhabitant of many eastern and
Mediterranean countries. There are about 85 species in all, and each of them is
remarkable in their own way. All the chameleons have the strange combination of
slow moving body , a quick drawing tongue and are mostly tree dwelling lizards.
They move through the twigs very slowly testing each branch before putting its
weight on it. Their EYES are UNIQUE too, moving independent of right and left
eyes, looking up, down, sideways, towards and behind searching for food such as
insects, spiders .etc,. Most Chameleons are medium sized lizards of about 15-30
cm in length,. There are some tiny ones
measuring a few centimetres. There are also giant chameleons measuring about 80
centimetres in Madagascar and Africa.
The Indian sub-continent and Sri Lanka has one species Chameleo
zylanicus (Indian Chameleon).
The Chameleo zeylanicus is
apple green in colour and lives among tree leaves This can change colour from
green and brown to shades of yellow , white or shades of black.
Contrary to popular belief, chameleons do not change colour matching
their back ground . Their colour changes are related to the surrounding
temperature and moods.
Their colour is apple green in day light under normal
conditions. But if you locate one using torch in the night on a tree , you will
observe a fluorescent pale whitish green shade. It is easy to spot them in the
night among the dark green foliage of leaves, where in they would be completely
protected in the day light. Their body has pigments that can turn lighter or
darker as need arises. The colour changes are related to various stimuli such
as change in temperature, difference in the incident light and shadows,
night and day, alarm signals, mating instinct , anger , defending mate from other rivals , etc.
Unless they increase their body temperature by absorbing
heat from the sun, they stay at the same temperature as the air around them.
Without warmth, they cannot hunt, move, or digest their food. In the morning
they squeeze their sides together and puff out their chins, flattening their
bodies to create more surface area. Dark colours absorb heat better, so the
side of the chameleon facing the sun becomes almost black, while the other
remains it usual colour! Chameleons are
"ectotherms", animals whose temperatures are controlled from outside
their bodies.
DESCRIPTION
The head has a bony casque,
ornamented with crests or tubercles. A separation between the eyes, the
interorbital septum, is present. Its dentition is acrodont; the teeth are
compressed, triangular, and more or less distinctly tricuspid. The palate is
toothless. The eyes are large, covered by a thick, granular lids pierced with a
small central opening for the pupil. No tympanum or external ear is present.
The body is compressed, and the neck is very short. The vertebrae are
procoelian; abdominal ribs are present. The limbs are long, raising the body.
The digits are arranged in bundles of two and three; in the hand, the inner
bundle is formed of three, the outer of two digits; it is the reverse in the
foot. The tail is prehensile. The head and body are covered with granules or
tubercles.
The casque is much elevated
posteriorly, with a strong curved parietal crest; the distance between the
commissure of the mouth and the extremity of the casque equals or nearly equals
the distance between the end of the snout and the hinder extremity of the mandible;
no rostral appendages occur; a strong lateral crest, not reaching the end of
the parietal crest, is present; an indication of a dermal occipital lobe is
found on each side, not reaching the parietal crest. No enlarged tubercles
occur on the body; a feebly serrated dorsal crest is present; a series of
conical tubercles form a very distinct crest along the throat and belly. Males
have a tarsal process or spur, the tail is longer than head and body. The
gular-ventral crest and the commissure of the mouth are white.
From snout to vent, it is
up to 7 in long, with a prehensile tail of 8 in.
They eat locusts,
mantids, crickets, and other insects that hover around flowers , but larger
chameleons have been known to eat small birds and other lizards.
Facts about Chameleon
1.
They have long tongue having a sticky tip
on the end, which serves to catch prey items that they would otherwise never be
able to reach with their lack of locomotive speed.
The tip of their tongue
is a bulbous ball of muscle, and as it hits its prey, it rapidly forms a small
suction cup. Once the tongue sticks to a prey item, it is drawn quickly back
into the mouth, where the chameleon's strong jaws crush it and it is consumed.
2. The
characteristics of changing their skin colour make them one of the famous
lizard family species. Changing the skin colour is an expression of the
physical and physiological condition of the lizard. The colour also plays an
important part in communication between other chameleons. If they are fearful or
territorial, their emotions will evoke a particular color/pattern.
3. Chameleons
have teeth to grasp onto food. Their teeth are also used to help them crush and
kill their food. They may chew or swallow their food whole. They can also use
their teeth for tearing chunks off and then swallow. Some chameleons hold the
dead prey in their mouth for several moments before swallowing it.
4. They lay
eggs in a 4 to 12 inches deep hole. Some species lay 2 to 4 eggs while other
species lays 80 to 100 eggs. Some species of chameleon give birth to young
ones.
5. They hear
vibrations in the air, which help them find food and stay safe from their
enemies. They are almost deaf, but can hear tones and feel vibrations.
6. Their eyes are
the most distinctive among the reptiles. The upper and lower eyelids are
joined, with only a pinhole large enough for the pupil to see through. They can
rotate and focus their eyes separately to observe two different objects
simultaneously. It in effect gives them a full 360-degree arc of vision around
their body.
7. They have
zygodactyl foot, on each foot the five toes are fused into a group of two and a
group of three, giving the foot a gripping and lifting like appearance. With
their specialized feet, they grip tightly to narrow branches.
Chameleons can even sleep
upside down!
- Besides changing colors and
patterns, chameleons also “talk” to each other by flattening themselves
sideways to look taller, rocking from side to side, curling and uncurling
their tails and opening their mouths.
- A chameleon’s tongue launches
at more than 26 body lengths per second. It accelerates from 0 to 20 feet
per second in 20 milliseconds.1 At 50 g (50 times the acceleration due to gravity),
the acceleration is 5 times the acceleration of a fighter jet.
- Some chameleons eat leaves in
addition to the standard insect fare. Occasionally, they will launch their
tongues at distant leaves and even water droplets. Perhaps in a pre-Fall
world, before Adam sinned, chameleons used their tongues in the same
fashion but ate only leaves. God foreknew the Fall, and His design of the
chameleon’s tongue would prove to be a great asset in the post-Fall world.
- Chameleons can sharply focus on
an object as little as one inch away.
- Chameleons are usually very
solitary. But sometimes you will see a pair of them together or one male
with several females.
- Some chameleons will dig pits
or tunnels to lay two to as many as eighty eggs, depending on the species.
Incubation can be as little as a month and a half to as long as two years.
Eggs within a clutch usually hatch within days of each other. The
offspring sometimes dig together to the surface, after which they are on
their own.
- The babies of some species,
especially those from mountainous environments, develop completely inside
the mother’s body. Shortly after birth, they break free of the clear
membrane encasing them.
- Males most often have more
elaborate ornamentations (such as the presence of or a greater number of
horns) and are more brightly colored than females. In some species,
however, females are extremely colorful, much more so than the males.
- Most chameleons are found in
sub-Saharan Africa as well as on the island country of Madagascar. Some
are also found in northern Africa, southern Europe, southern India, the
Middle East, Sri Lanka, and several smaller islands in the western Indian
Ocean. They live in varied habitats, from rainforests to savannas and even
deserts.
- Fact 1:
the Weird Tongue
- Chameleons move very slowly and
with great deliberation. To allow them to catch their prey they have
evolved a very special tongue, which is extremely long, often it is longer
than the body. The tongue can shoot out of the mouth and catch its prey
with extraordinary speed, approximately 30 milliseconds (30 thousandths of
a second). At the tip of the tongue there is a suction cup like structure,
covered in mucus. When a chameleon sees an insect, it is very still, and
captures the prey with its tongue, before the insect realizes that it is
about to become dinner.
- Fact 2,
its Eyes Can Move Independently
- Chameleon eyes are also
unusual. The upper and lower eyelids are fused, covering most of the eye
except for the pupil. The eyes are very mobile, and can swivel
independently of each other. Thus giving them almost 360o
degree vision and allowing to focus on 2 objects at once. This allows the
chameleon to search for food in its vicinity very effectively. When an
insect is spotted, it can focus on it with both eyes, so it can judge
distance and extend its tongue out with great accuracy.
- Pincer
like feet
- Chameleon foot anatomy is also
unlike that of other lizards, and is perfectly adapted to grasping
branches and twigs. The toes on each foot are partially fused into two
groups, one consisting of 2 toes while the other has 3. This makes
chameleons didactyl and gives their feet a pincer-like appearance,
allowing them to grasp objects. On the front feet the 2 toed group is on
the outside, while the 3 toed group is on the inside, and on the back feet
this order is reversed. Each toe ends in a sharp claw which allows helps
with climbing tree bark.
This type of
long legs leads to their slow movement in flat surface like road and are not
meant for running.
Hence they
are susceptible to be run over by vehicles unless we have humane DRIVERS WHO
LET THEM PASS.
ELSE THEY
DIE AS SEEN BELOW
Changing
Colour for Social Interactions
Many lizards can change
colour to a certain extent, but chameleons can do this to a remarkable degree.
Although this aides camouflage, the main purpose is communication with other
lizards, either warning off rivals, or attracting females.
Chameleons are solitary and
very territorial animals, males do not tolerate other males in their territory,
and will colour up to warn them off. They generally turn dark when they are
angry. Changing colour also helps them thermoregulate, they become darker when
cold, to absorb more sunshine, and paler when they are too hot.
Chameleons can alter their
colour rapidly because their skins contain three types of pigment cells
arranged in three layers. The top layer consists of xanthophores, and
erythrophores, which contain yellow pigment. The layer below that consists of
cells called iridophores which appear white or blue. Below that are the
melanophores, containing melanin which is black. The distribution of the
pigment granules in the cytoplasm of each type of cell is controlled by the nervous
system and controls the appearance of the skin, when the pigment granules are
distributed evenly thoughout the cell, it appears intensely coloured, whereas
when the pigment is concentrated in a tight spot in the centre, the cell
becomes almost transparent. Hence the chameleon can have different patterns,
which can rapidly change depending on its mood.
In the night they mostly
sleep on the tree with its florescent green colour or breeding time colour.
