Those in the center of the jaws are low and triangular while those on the sides are more conical and slightly recurved. There is typically a wide space on the center of the upper jaw with only scattered teeth. However, it is the only one that relies solely on the passive flow of water through its pharynx by swimming. The other two assist the process by suction or actively pumping water into their pharynxes. The basking shark is usually seen swimming with its mouth wide open, taking in a continuous flow of water.
Food is strained from the water by gill rakers located in the gill slits.
The 1000-1300 gill rakers in the basking shark's mouth can strain up to 2000 tons of water per hour. Occasionally the basking shark closes its mouth to swallow its prey. There is a theory that the basking shark feeds on the surface when plankton is abundant, then sheds its gill rakers and hibernates in deeper water during winter. It is not known how often it sheds these gill rakers or how rapidly they are replaced. Reproduction Limited information is available on the reproduction of the basking shark.