美国科学60秒 SSS 2013-05-31

（单词翻译）

　　Baleen¹ allows the non-toothed whales to strain sea water for the fish and crustacean² pray. Alexander Werth of Hampden Sydney College of Virgina avoided a Jonah like journey, and still managed to analyze³ 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 dense⁴ beleen, that looks like folded accordion⁵. They gulp⁶ water to feed. For tests, Werth submerged racks of Humpback and Bowhead baleen in a flow tank. Plastic beads⁷ represented food. As water streamed by, filaments⁸ from neighboring beleen plates naturally twined together and trap the beads. The Bowhead's long fringe, formed the more effective filter, perfect for catching⁹ 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 specially¹⁰ creative.