How do fish breath?

Fish breathe through gills, which extract oxygen from water. Here's a simplified explanation:

*How Fish Gills Work:*

1. Water enters the fish's mouth.

2. The fish's gills, located on either side of its pharynx, absorb oxygen from the water.

3. The gills contain thin filaments that increase surface area for oxygen absorption.

4. Oxygen-rich water passes over the filaments, allowing oxygen to diffuse into the bloodstream.

5. Carbon dioxide and other waste products diffuse out of the bloodstream and into the water.

6. The deoxygenated water exits the fish's body through the gill slits.

*Key Structures:*

1. Gill rakers: Bony or cartilaginous structures that support the gills.

2. Gill filaments: Thin, branching structures that increase surface area.

3. Gill lamellae: Folded structures within the filaments that facilitate oxygen exchange.

*Breathing Process:*

1. Fish take in water through their mouth.

2. The water passes over the gills, allowing oxygen absorption.

3. The fish's operculum (gill cover) opens and closes, creating suction to draw water over the gills.

4. The fish's heartbeat pumps blood through the gills, facilitating oxygen exchange.

*Interesting Facts:*

1. Some fish, like labyrinth fish, have developed air-breathing abilities.

2. Sharks and rays have modified gills that allow them to breathe more efficiently.

3. Fish can also absorb oxygen from aquatic plants and algae.