What is the common name for Balaenoptera physalus?

The common name for Balaenoptera physalus is the fin whale.

The fin whale is a large baleen whale and the second-longest cetacean after the blue whale. It is also called the finback whale or common rorqual. The name “rorqual” refers to whales with longitudinal throat grooves that expand during feeding, allowing them to engulf large mouthfuls of seawater and prey.

Fin whales have long, slender bodies, dark brownish-gray upper sides, and paler undersides. This countershading can make them less conspicuous when viewed from above or below. A particularly useful identification clue is their asymmetrical head coloration: the right side of the lower jaw is often pale, while the left side is darker.

Fin whales eat krill, small fish, and other schooling prey by filtering water through baleen plates. They are among the fastest large whales and can reach about 37 kilometers per hour in short bursts. They are sometimes confused with sei whales or minke whales, but fin whales are generally much larger and have a more prominent, distinctive blow. Commercial whaling severely reduced their numbers, and the species remains listed as vulnerable.