Aquatic Adaptation

The entire space occupied by living organisms is termed as a biosphere. All organisms are adapted to their environment. A habitat is a place where organisms live.

Adaptation is defined as the process of adjustment of an organism to its environment. Organisms show the adaptation in the following ways:

1. By losing and gaining of organs.
2. By changing the color of body according to the habitat
3. By the modification of organs

Aquatic adaptation

Aquatic plants (Hydrophytes) and their adaptational characteristics

The plants which grow, derive food, multiply and adjust themselves inside water are called aquatic plants. On the basis of mode of life, hydrophytes are of following types:

1. Free floating plants. (E.g. hyacinth, water lettuce, Wolffia etc.)
2. Submerged plants. (E.g. hydrilla, Sagittaria etc.)
3. Rooted submerged plants. (E.g. lotus, water lily, etc.)

The following are the adaptational characteristics of hydrophytes:

1. The root system of aquatic plants is properly developed.
2. Hydrophytes have a waterproof and protective waxy coat on its surface which prevents them from decaying.
3. Hydrophytes have air cavities in their tissues which help them to float.
4. Conducting tissues (xylem and phloem) are less developed in them.
5. The stem of the aquatic plant is long, slender, spongy and flexible.
6. Conducting tissues (xylem and phloem) are less developed in them.
7. They have a waterproof and protective waxy coat on its surface which prevents them from rotting and decaying.
8. Hydrophytes have air storage tissues called aerenchyma which help them to float

Aquatic animals and their adaptational characteristics

1. The animals which grow, multiply and adjust themselves inside water are called aquatic animals. The following are the adaptational characteristics of aquatic animals:
2. The body of aquatic animals is streamlined i.e. trapped at both ends. Head is blunt and tail is long.
3. The body is provided with air sacs or air bladder so that they do not sink when they stop swimming.
4. They have paired and unpaired fins, flippers and paddles and webbed legs for swimming.
5. They have gills as a respiratory organ.
6. The body is provided with a lateral line as a sense organ.
7. They can change their body temperature with respect to the temperature of surrounding.
8. Aquatic birds have flat beaks for catching their prey and webbed legs for an easy swim.

Examples: fish, frog, duck etc.