ocr: Blue whales, which like other whales have good vision and excellent hearing, maintain their weight on a diet of krill- small, shrimplike animals abundant in cool waters, usually living within thirty feet of the surface. Having no teeth, the blue whale takes in a great mouthtul of krill, closes its mouth, raises its tongue, and strains out the water through the overlapping plates of baleen (whalebone") that hang from the upper jaw. Then it swallows the krill. The stomach of an eighty-seven-foot 48