the fin whale is a streamlined whale that is found worldwide; it is most common in the north atlantic. there are three separate populations of fin whales, one in the north pacific, one in the north atlantic, and one in the southern hemisphere; they do not interbreed. many groups of fin whales migrate between feeding grounds and breeding grounds. this whale usually swims in pods of 3-7 whales but larger groups (up to 300 animals) may form at rich feeding grounds.