Anglerfish
In some deep-sea anglerfish, tiny males fuse permanently to much larger females, sharing their blood supply for the rest of their lives.
Fish
Arapaima
The arapaima must rise to the surface to gulp air every 5 to 20 minutes, because it gets most of its oxygen by breathing air.
Archerfish
Archerfish shoot jets of water up to about 3 metres to knock insects off leaves, correcting for the way light bends at the water’s surface.
Atlantic Bluefin Tuna
Bluefin tuna are warm-blooded fish: a heat exchange system in their blood vessels keeps their muscles much warmer than the surrounding water.
Atlantic Cod
The collapse of the cod stocks off Newfoundland in 1992 put about 40,000 people out of work and became a global warning about overfishing.
Atlantic Goliath Grouper
Goliath groupers can make loud, booming sounds with their swim bladders that divers can feel as well as hear.
Atlantic Salmon
Atlantic salmon find their way back to the exact river where they hatched, years later, largely by recognising its smell.
Basking Shark
The basking shark is the second-largest fish in the world, and it filters up to about 2,000 tonnes of water an hour through its huge open mouth.
Beluga Sturgeon
The beluga sturgeon is one of the largest bony fish ever recorded; a female caught in the Volga in 1827 was reported at over 7 metres and about 1.5 tonnes.
