Aquatic Habitat and Special Adaptations

Habitat of Animals

Aquatic Habitats and Special Adaptations for Class 5 Science

Many animals live in the water instead of living on the land. These are called aquatic animals. These animals are adapted to live in the aquatic habitat.
After reading the concept, students will be able to:

Explain the difference between freshwater animals and marine animals.
Understand that webbed feet birds can swim on the surface water.
Analyse what is streamlined body and how it helps fishes to swim in the water.
Know that fish breathe through gills and this type of breathing is called gill respiration.
Understand what is a blowhole and its importance in lung respiration.
Explain about diurnal animals with examples and nocturnal animals’ meaning.

Each concept is explained to class 5 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.

Download the worksheets and check your answers with the worksheet solutions for the concept of Aquatic Habitats and Special Adaptations provided in PDF format.

Aquatic Habitat:

Aquatic habitats are habitats in water. It includes regions that are always covered by water and the surrounding areas that are sometimes occupied by water. Aquatic habitats are classified as follows—

Aquatic animals and birds are specialized to live both on the surface of the water and inside water. Their bodies show different types of adaptations based on the choice of their habitats.

Aquatic animals have the following adaptations in common—

Their bodies are streamlined so that they can swim easily. They also have swim bladders in their bodies.
Gills are usually used for respiration.
Fins and tails are used for locomotion.
The body is covered with scales that protect the delicate body from excessive salt in the water and help in moisture retention.
Saltwater fishes drink large quantities of water that helps remove excess salt from their body.

Let us now look at some aquatic animals and their unique adaptative features.

Duck:

The duck is an aquatic bird adapted to live on the surface of water or land near water bodies.
It feeds on pondweed, snails and insects.
It is adapted to fly, dive and paddle.
Its webbed feet make it a great swimmer.

Fish:

Fishes have a streamlined body for swimming easily in water.
They use their gill for breathing.
The tail helps them navigate through water in the right directions, whereas the fins help in locomotion.
The scales on a fish’s body helps prevent loss of moisture.

Whales and Dolphins:

Whales and dolphins are aquatic mammals.
They are adapted to live inside water.
Their body is streamlined, which enables them to swim swiftly.
Unlike fishes, they use their lungs for breathing. They come up to the surface of the water to fill their lungs with oxygen and dive back.

They have blowholes on their heads which are used for gaseous exchange.
There is a remarkable difference between the temperatures inside and on the surface of the water. To manage this varying temperature, whales and dolphins have a thick layer of blubber that enables them to regulate their body temperature.
Blubber also helps these huge animals stay afloat by providing buoyancy.

Frogs:

Frogs are amphibians.
During their life cycle, they have a larval stage called tadpole.
Tadpoles are aquatic. They do not survive outside water.
Frogs use both lungs and skin for breathing.
Lungs are useful when they are outside water, and the skin is used when inside water.
Apart from these adaptations, their body is also adapted for swimming.
Their hind limbs are longer than the forelimbs.
They have webbed feet which act as a paddle while swimming.

Sea Star/Starfish:

It has a protective shell on its body.
They have spiny skin that allows them to ward off predators.
A starfish has the unique ability to regenerate lost body parts, and it helps them survive among the marine predators.

Octopus and Squids :

They have highly developed eye sights.
They change the colours of their skin using chromatophores.
They eject an ink-like substance as a defence mechanism against predators.

Special Adaptations :

Cursorial Animals:

Animals that are specifically adapted to run are called cursorial animals.
These animals are adapted to long-distance running.
Their streamlined body helps in fast movement.
They have strong forelimbs and hindlimbs.

Examples : Horse, wolf, leopard.

a.Fossorial Animals:

Animals adapted to live underground, either in burrows or in tunnels, are called fossorial animals.
They have small bodies with a snout.
Some animals have forelimbs that are short and accompanied by sharp claws.
Their eyes and ears are small.

Examples : Ant, mole, earthworm, shrew.

b.Diurnal Animals:

Animals that are active during the day are called diurnal animals.

Examples : Dog, elephant, butterfly, squirrel.

c.Nocturnal animals :

Animals that are active only during the night are called nocturnal animals.

Examples : Bat, owl, cockroach.

New Words

Streamlined : A body shape that tapers at both ends.

Swim bladder : It is an organ in bony fish that is filled with oxygen. This organ helps the fish to maintain its depth without floating upward or sinking downward.

Chromatophores : Cells that produce colour.

Forelimbs and hindlimbs: Limbs in the front part of the body are called forelimbs. Limbs in the posterior part of the body are called hindlimbs.

Did You Know?

Pufferfish is also called blowfish. It ingests water and air very quickly to attain a larger size. It allows them to evade predators.Dolphins have adapted themselves to the presence of humans. Irrawaddy Dolphins help the fishermen catch fish, and in return, the fishermen reward them with some fish from their hunt.Wood frogs freeze their blood while hibernating.

Birds perform mating dances. For example, a male peacock dance to attract the female peacock for reproduction.An adult tortoise can survive without water for a year. They store water in their oversized bladders.Jellyfishes do not have a brain or a heart.