Which whale has the longest baleen plates?

The bowhead whale has the longest baleen plates of any whale, with individual plates reaching about 4.5 metres.

Baleen is made of keratin, the same structural protein found in human fingernails. Instead of teeth, bowhead whales have hundreds of overlapping plates hanging from the upper jaw. They take in large mouthfuls of seawater and use the baleen fringe to strain out zooplankton, especially copepods and krill.

Bowheads are Arctic and sub-Arctic baleen whales with massive heads that can break through sea ice. Their thick blubber helps them survive frigid water, and some individuals may live for more than 200 years. They were heavily hunted historically because their baleen, oil, and thick blubber were valuable.

The blue whale is larger overall, but the bowhead’s baleen plates are longer. Baleen length is therefore a different record from body length, and the two whales should not be confused on that basis.