Page 93 - Science Class 06

Adap ve Feature of Aqua c Animals The word ‘Amphibia’ means dual lives.
Body of most aqua c animals is laterally
compressed to reduce fric on in water. This
shape of body allows them to make a swi
passage in water while swimming.
Most of the aqua c animals have streamlined body.
Most of the aqua c animals have gills for
respira on. Gills use dissolved oxygen of
water.
Aqua c animals have special appendages
called fins. These maintain the balance of
their body and help in movement through
water.
Aqua c animals have air-filled organs and
swim bladder. They maintain buoyance and
also help in swimming and respira on.
The body of aqua c animals is covered with
scales which protect them from decaying.
The head of the aqua c animals is in a
conical shape that makes an easy passage in
water.
Amphibians
Amphibians, in the simplest defini on, are
animals that live in both water and on land.
Science-6
Amphibians are cold-blooded vertebrates
that include the well-known frogs and
toads. Being cold-blooded means that they
depend on environmental sources of heat
to regulate their body heat and tempe-
rature. The class of Amphibia is made up of
more than 3,500 species which include the
various order of amphibians.
1. Why do the aqua c animals have
streamlined body?
2. What is the func on of gills?
3. What is the func on of fins?
4. Why the head of the aqua c animals is
conical in shape?
Adap ve Feature of Amphibians
Amphibians also have a streamlined body
with enlarged tail.
Amphibians do not have scales on their
body. However, their skin is smooth, dry and
rich in mucus. It keeps them moist and
helps in respira on.
They have very short neck which has no
power of mobility.
The frog’s front pair of legs is short and the
back pair is long. Its feet are webbed and
helped the frog to swim in water. The two
pairs of legs help them to jump with ease.
Frogs have a s cky tongue and insects get
stuck in it.
The bones of amphibians are light and
spongy. This reduce their body weight and
makes them light.
93