What is the world's largest fish?
The harmless whale shark holds the title of largest fish, with the record being a 59 footer captured in Thailand in 1919.

Whales and dolphins have a tool called echolocation, a sonar which allows them to "see" their prey, even it's internal workings! Noise pollution in the water has a significant effect on whales ability to navigate, hunt, locate their pods, and reproduce.
Echolocating animals have two ears positioned slightly apart. The echoes returning to the two ears arrive at different times and at different loudness levels, depending on the position of the object generating the echoes. The time and loudness differences are used by the animals to perceive direction. With echolocation the bat or other animal can see not only where it's going but can also see how big another animal is, what kind of animal it is, and other features as well. - wikipedia
Many modern submarines use their own sonar a low and mid-frequency sonar is so deafening the pressure waves affect animals on the cellular level, causing the equivalent of "the bends" or decompression sickness. For animals with echolocation this causes sonar function to fail and leaves these animals blind, if they're lucky. What often results is massive beachings (update: court blocks sonar 7/6/06)
More animal facts.
The harmless whale shark holds the title of largest fish, with the record being a 59 footer captured in Thailand in 1919.
Prairie dogs, those little pups popping in and out of holes on vacant lots and rural rangeland, are talking up a storm. They have different "words" for tall human in yellow shirt, short human in green shirt, coyote, deer, red-tailed hawk and many other creatures.
There is an ant in Brazil that has a gland which causes the ant to explode like a bomb, spraying a sticky toxic
goo on everybody nearby. Now that's some hard core biology!