I have seen a school of bluefish run through an acre or so of mullet, leaving nothing but a bloody oil slick in a matter of a few minutes.
Here is my favorite shark story: We had a charter for kingfish(slimefish, I hate em), and it was a little slow, so we were backing up to shrimp boats and drifting icefish off of them.
The water was only about 50' deep, and if your bait got within a few feet of the bottom, small(18"-36") shovelnose sharks would take it every time. Since I was the mate, I had the pleasure of dicking with them and saving the tackle. This one salamander thought it was funny to watch me remove them from his hook, and kept letting it settle to the bottom.
Finally, a little bitty one flipped out of my hand into the cockpit, and began thrashing around. The smarter of us hauled bellybutton for the flybridge or the cabin, but the salamander just stood there laughing.
The little shark clamped onto his calf, and would not let go, and now the salamander began thrashing! After I quit laughing, I squeezed his head(the shark's) and threw him over board. The salamander had a nice round chunk of meat taken out of his leg, and his (drunk) buddies would not let us return to port for another 4 hours. Needless to say, he was a bit nicer after that, as I patched him up.
Another time, when I was a kid, I caught a perfectly formed hammerhead that was only about 8 inches long. I put him in the ice chest, and many hours later, when we got back to the dock, I revived him, and he swam away. Amazing critters they are.
p.s. The biggest shark I have SEEN is a 25 foot plus hammerhead off of Okracoke about 30 miles. I know he was that big because he swam down alongside the boat, which was a 25 footer, and he was longer than it was.
The biggest I have CAUGHT(not me personally, but the boat I was on) is a tiger off the mouth of the Mississippi river that would have went easy 600#s, but we cut him off at the boat. That one hit a Marlin lure being trolled at 18 knots, and he launched about 10 foot into the air and ate the bait on the his way down. Pretty cool, man, let me tell you.