Fish respire through gills.
Respiration in Fish
- Fish use their gills to help them breathe. The majority of fish have gills on both sides of their heads.
- Gills are tissues made up of gill filaments, which are feathery structures that provide a wide surface area for gas exchange.
- Since water contains very little dissolved oxygen, a wide surface area is essential for gas exchange in aquatic species.
- The filaments in fish gills are organized in rows in the gill arch. Each filament comprises lamellae, which are discs supplied with capillaries.
- Blood moves in and out of the gills through these small blood vessels.
- Though gills in fish occupy only a small section of their body, the extensive respiratory surface produced by the filaments renders the whole organism with efficient gas exchange.