美国科学60秒 SSS 2013-05-31（在线收听）

　　Baleen allows the non-toothed whales to strain sea water for the fish and crustacean pray. Alexander Werth of Hampden Sydney College of Virgina avoided a Jonah like journey, and still managed to analyze how baleen works. Two kinds of whales sport baleen. Baleanid whales such as the Bowhead, have long springy plates of the delicate fringe. They filter water continuous. Groove-throated whales such as Humpbacks have dense beleen, that looks like folded accordion. They gulp water to feed. For tests, Werth submerged racks of Humpback and Bowhead baleen in a flow tank. Plastic beads represented food. As water streamed by, filaments from neighboring beleen plates naturally twined together and trap the beads. The Bowhead's long fringe, formed the more effective filter, perfect for catching tiny krill. But the humpback baleen still nabs plenty. The study is in the journal of Experimental Biology. If you are going to be a massive carnivore without teeth, evolution has to be specially creative.