Page 3 - Grade 4 Q2W2

Animals that live in water are called aquatic animals. Fish, squid, crabs,
lobster, mussels live underwater. Fish are covered with scale for protection from

diseases and from other animals that live in water. Their scales are smooth and

slimy, arranged overlapping from head to tail so as the water slips smoothly as it
moves forward.

Shrimps and lobster are covered with outside skeleton or exoskeleton while
another animal like clams and mussels are covered with shells. Clams swim by

clapping their bivalves. Squids use their tentacles and octopuses use their arms to

swim. They squirt water as they swim.
Fish have gills for breathing underwater and fins for swimming. These parts

are important because they help them survive in water. An adaptation is the
structure of behavior that help an organism survives in its environment. Animals

have body structures that help them adapt to water.

Let’s Apply

Which is which??
Using habitat or body structures as basis, cross out (x) the animal that does not

belong to the group. Use a separate sheet for your answer.

1. lobster, cat, shark, dolphin
2. snake, clam, milkfish, squid

3. octopus, stingray, bear, salmon
4. jellyfish, oyster, eel, earthworm

5. crocodile, crab, coral, whale

Let’s Analyze

Most animals have several body systems that help them maintain stability

in order to survive, grow, and reproduce. Each of these systems is made of organs