The second largest fish in the world, like their larger counterpart - the whale shark - they feed on plankton.

Statistics
The largest recorded basking shark was 12.3m, but on average, females are 8.9m and males are 6.5m.

Physical description
Basking sharks are a deep blue/charcoal colour with a pale belly. They are easily distinguished by their large, gaping mouth and large gill slits, used for feeding. They have many small teeth, about a hundred per row.

Distribution
Basking sharks inhabit the North and South Atlantic and Pacific Oceans.

Habitat
They prefer surface waters of the open sea, but travel further inland to breed in the summer.

Diet
Basking sharks are slow swimmers, travelling at speeds of only 3 mph. As they drift through the water, they open their huge mouth and filter out plankton from the water by expelling excess water through their gill rakers and trapping food particles.

They take in an estimated 1,482,000 litres of water an hour, using more than 5,000 gill rakers to strain the food. In winter, they lose their gill rakers, suggesting that they cannot feed during this time.

Behaviour
This species can often be found in groups of 3-4, although groupings of 100 individuals have been recorded.

Reproduction
Basking sharks develop in eggs inside their mothers, and hatch as soon as they are released from her body. They are about 1.5m long at birth.

Conservation status
Basking sharks are considered to be Vulnerable, except for the north Pacific subpopulations and the northeast Atlantic sub-population, which are Endangered. In the past, they were hunted extensively for liver oil.