Behavior of the Basking Shark

The Basking Shark (Cetorhinus maximus) is a filter feeding shark, meaning it filters food through its gills rather than attacking and killing prey. Though reaching up to about 40 feet (over 12 metres) long, it frightens many people. It is the second-largest shark (after another filter feeder, the Whale Shark.). Few things attack a Basking Shark, mainly just the occasional Orca, Tiger Shark, or Great White.

The Basking Shark is also referred to as the sunfish or sailfish due to its habit of riding on the surface with its mouth open collecting food. This large creature swims through the water with its mouth open, allowing water filled with plankton to flow through its mouth. The prey includes plankton, baby fish, and fish eggs. After filtering the water for substance, it is expelled through the shark’s 5 pairs of gill slits. The Basking Shark can filter over 1500 gallons (almost 6000 litres) of water per hour.

Basking sharks prefer moderate temperatures and live in coastal temperate waters primarily along the Continental Shelf. While they do spend most of their time at the surface “basking”, they have been recorded to move to depths of almost 3000 feet (900 metres) in the winter. They also migrate south during the winter. This caused many people to believe that they were hibernating, but they were merely following the food supply.

Social behavior is found in Basking Sharks with them forming schools, usually groups of three or four, but sometimes up to 100. Since they are so large few things eat them and as they move slowly, they do not attempt to evade boats or divers and are harmless. Females will often go into shallow water to give birth to just two or three young, but the young are generally over 5 feet (1.5 metres) long, extremely large for a shark! How often they breed or survival rates are not known, but appear to be infrequent as they are becoming endangered.

While the Basking Shark generally moves slowly, it can actually jump with part of its body out of the surface, similar to breaching seen in whales and dolphins. The reason for this behavior is unknown, but it is suspected that they are trying to dislodge parasites.

And that is a summary of the behavioral characteristics of this rare but fascinating creature. For more detailed information (and where much of this information came from) please check out Wikipedia website and also The Enchanted Learning website.