美国科学60秒 SSS 2012-11-08(在线收听

 Crampfish became famous thanks to the movie Finding Nimo. In real life, their social hierarchy is simple, larger fish dominate their smaller counterparts. Now we know that to reinforce the social structure, the fish communicate with aggressive and submissive audio signals. The news [infoes] in the journal PLoS ONE. 

Researchers recorded crampfish calls capturing this noise as one chased a smaller fish. These popping sounds functioned as an () aggression signal. When the/a [confish] has been chased and wishes to submit, it [cheek]s its head in a submissive gesture and produces [quicking] noises like these. 
The researchers compared the aggressive and submissive calls and found that the sound posed in a submissive signal were shorter and more high-pitched. Unlike many animals that use sounds to drive/draw in potential mates, crampfish appear to use their calls only as a [lib] of social status. When a little fish makes submissive sounds to a larger one, neither has to invest in a physical confrontation, which is good news for small [fry], like Nimo.
  原文地址:http://www.tingroom.com/lesson/sasss/2012/11/216405.html