英语听力：自然百科 大堡礁 自然奇迹(23)（在线收听）

Within half an hour, the fish is completely enveloped in a slimy cocoon, which traps its smell.

不到半个小时，鹦鹉鱼就整个包裹在一个防止气味外泄的黏糊糊的茧里了。

But not all the reef hunters are fooled.

但道高一尺魔高一丈。

White tipped reef sharks do use smell to find their prey.

白顶礁鲨的确通过气味来寻找猎物。

But if that doesn't work, they have another sense.

但如果这个不管用，它们还另有妙招。

They can detect an animal's bioelectrical energy, the tiny electrical signals given off by even the smallest of its twitching muscles.

鲨鱼能探测到其他动物身上的生物电能，即使是由微笑的抽搐引发的电流。

This resting parrotfish risks discovery every time it moves a fin or wafts its gills.

鹦鹉鱼每次移动鱼鳍或者鼓动鱼鳃都有被鲨鱼发现的危险。

As the sharks pass, it holds its breath.

当鲨鱼游过时，鹦鹉鱼都屏住呼吸。

But sharks don't give up that easily.

但鲨鱼不会这样轻易放弃。

White tips are the perfect size and shape for hunting in this cramped spaces.

而白顶鲨的尺寸和形状都极为适合在这些狭窄的礁石缝隙中捕猎。