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.

Beluga whales are at the top of the food chain. A nice distinction, but it also means they acquire the sum total of toxins acquired by organisms all the way down the chain because these toxins such as PCB and heavy metal poisoning don't break down. Belugas, in fact, are so full of contaminants, when they are found beached they qualify as a toxic biohazard.
More facts about animals.
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!