rorqual

Any of a family (Balaenopteridae) of baleen whales, especially the genus Balaenoptera, which includes the blue whale B. musculus, the largest of all animals, measuring 30 m/100 ft and more. The common rorqual or fin whale B. physalus is slate-coloured and not quite so long.

The sei whale B. borealis, the minke whale B. acutorostrata, Bryde's whale B. edeni, and the humpback whale Megaptera novaeangliae also belong to this family. All are long-bodied whales with pleated throats.

Italian biologists, who published their research in March 2000, measured the depth to which common fin whales Balaenoptera physalus could dive and found that one whale reached 470 m, the deepest ever recorded for any species of baleen whale.