When Jaws swims in for the kill, it's to the foreboding music of John Williams. But piranhas sound their own drumbeats. Red-bellied piranhas (Pygocentrus nattereri), for example, make barking noises when caught. To figure out how the fish vocalize underwater, researchers observed them in a tank. The fierce predators made three types of angry grunts:
First, when fish stare down their rivals face-to-face, they utter rapid calls, much like those same barks.
(當魚面對面他們的競爭者凝視時，他們發出迅速的呼喊，類似的狗叫聲一樣。)
(這種聲音~把魚抓起來的時候~聽過)
During full fish-on-fish fights, the piranhas tend to emit two low thuds.
(當魚發生爭鬥時,往往會發出兩次低沉的砰一聲,聽起來像敲桌子)
The scrappy fish achieved both noises using ultra-fast muscles that beat against their swim bladders, air-filled chambers that aid in flotation, the group reports today in The Journal of Experimental Biology.
The third call is the nastiest; piranhas gnash their teeth while chasing another fish away from their dinner.
(第三種聲音~最嚴重~當晚餐時~食人魚咬牙切齒他們的牙齒，而追咬另一隻魚)
參考文獻
http://www.bbc.co.uk/nature/15274875
http://jeb.biologists.org/content/214/21/3613.abstract
Sound production in red-bellied piranhas (Pygocentrus nattereri, Kner): an acoustical, behavioural and morphofunctional study
http://news.sciencemag.org/sciencenow/2011/10/scienceshot-the-physiology-of-piranha.html?ref=hp
