Question

Write any two adaptations of aquatic animals.

Answer 1

Hint: An aquatic animal is, either vertebrate or invertebrate, which lives in the water for most or all of its lifetime. Aquatic animals may breathe air or obtain oxygen that is dissolved in water through special organs called gills, or directly through the skin.

Complete answer:
All organisms need oxygen to survive. Without oxygen, organisms will die. Aquatic organisms have adapted themselves to a life in the water by various means. They take in dissolved oxygen that is in the water or come up to the surface of the water to take in air. They have adapted a lot according to their body type, among many, the two adaptations of aquatic animals are:-
Gill chambers
Some aquatic organisms do not stay in the water all the time. They come out of the water
and move around on land but only for short periods. In addition to gills for them to breathe underwater, they also have gill chambers. A crab is one aquatic organism that has a gill chamber. A gill chamber is a special space in its body that allows it to store water. The filaments of its gills dangle down into the base of the chamber into the pool of water. Therefore, as long as the crab keeps its gill filaments moist, it can extract oxygen from the surrounding air in the gill chamber.

Skin
Some aquatic animals breathe using their skin. Some salamanders have no lungs or gills. Instead, they breathe through their moist skins. A frog can live on land and in water. An extensive number of blood vessels can be found throughout the frog’s skin. Dissolved oxygen passes through its membranous skin and directly enters into the bloodstream when the frog is in the water.

Note:
The other adaptations of aquatic animals are special nostrils. These nostrils allow them to breathe in air. They also have breathing tubes, which helps in the intake of oxygen. They also have bills which allow them to breathe in water. Some of the aquatic animals also carry air bubbles within them which helps them to breathe underwater.