What is a Fish?
Fish is a vertebrate organism that lives in water and breathes through its gills.
Which different body structures of a fish help in locomotion?
There are three main structures that aid in locomotion: streamlined body, fins, and tail.
(i) Streamlined body
Fish have a streamlined body. It means that the body has Bulged in the centre, but Tapering at both the ends. This type of body offers little or no resistance to the flow of water allowing easy movement in the water.
(ii) Fins
Fins are the small limb-like structure on the body of the fish that enables it to move. Fins that are present laterally (on the sides) are called Pectoral Fins.
(iii) Tail
The tail helps in the locomotion of fish by displacing the water allowing fish to move forward. The fins that are attached to the Tail of the fish are called Caudal Fins.
The body structure of a fish
How do fish locomote?
- The fish usually possess Pectoral Fins. When swimming, they propel the water behind and generate a force which in turn moves the fish
- The Caudal Fins participate in the locomotion by Propulsion.
- The muscles of the Anterior end of the body get stretched and curve the body in one direction. At this time, the tail at the Posterior end curves on the other This creates a jerk while pushing the body forward. A series of jerks together help the fish to swim.
Summary
| Fish | It is an aquatic vertebrate organism. |
| Different Body structures of Fish | There are three main structures that aid in locomotion
– Streamlined body – Fins – Tail |
| Locomotion in Fish | The fish moves forward with the help of the tail and fins. |