Question

Explain the features of fishes which help it to adapt to live in water.

Answer 1

Gills are evaginations on the surface of the body. Some are accessible to the environment, while others, like those found in fish, are enclosed in a hollow. Lungs, on the other hand, are invaginations of the body's surface. Gills are used by most invertebrates for gas exchange; a few, such as the pulmonate land snail, employ lungs. The main distinction between gills and lungs is that gills specialise in respiratory organs for breathing in water, whereas lungs are specialised respiratory organs for breathing in air.

Complete answer:
In fish, body shape is also an essential adaptation. To assist them move through the water, fast-moving fish have long torpedo-shaped bodies. Other fish that live near the river's or stream's bottom have longer, flat bodies. Most fish have fins, which vary in position and shape depending on the species.
Features that assist fish in adjusting to life in water include:
i. Scale-covered body with a streamlined, spindle-like form. This provides the least amount of resistance to the flow of water, making it easier for them to swim.
ii. The backbone of the skeleton is flexible and made up of thin bones.
iii. Flat fins and tails to aid in swimming, changing directions, and maintaining body balance.
iv. Fishes' gills are the organs that allow them to breathe. They have the ability to take oxygen from the water.
Gills are evaginated respiratory surfaces that are used for water breathing. All amphibian larvae, as well as some aquatic salamanders, have gills. They're usually complex, branched formations.

Note:
Fish can be found in almost every type of aquatic environment. Fish have evolved to live in a variety of locations, including rocky coastlines, coral reefs, kelp forests, rivers and streams, lakes and ponds, under sea ice, the deep sea, and other fresh, salt, and brackish water settings. Behavioural responses are actions taken by an organism to help it live and reproduce. Physiological - a biological function that helps the life and reproduction of an organism. Structural - a characteristic of an organism's body that aids survival and reproduction.