FISH THAT CAN BREATHE AIR
Labyrinth fish are named after their lung-like labyrinth organs, which have many maze-like compartments known as lamellae. Those labyrinth organs help some fish species, including bettas, gouramis and paradise fish, to breathe air just like humans do. They also have gills so they can breathe oxygen dissolved in water.
For millions of years, these fish and their ancestors have lived in very low-oxygen waters. Evolution has favoured any fish that are born with advantages that help them make the most of the oxygen they can find.
If the water labyrinth fishes live in runs out of oxygen, they can dash up to the surface and use their labyrinth organs for a gulp of air. They can even survive for hours outside of the water. Many labyrinth fish also build bubble nests. Males can blow bubbles to create elaborate nests of air at the surface of the water.