I'll say this.
Not sure if this fact is true or not, but it sounds reasonable given the following experience.
I've been told several times that Bull Sharks have the highest concentration of testosterone in any animal on earth, including human men.
That being said, one time while fishing about 200 yards offshore for Cobia, we hooked into a massive bull shark. I had seen him swimming around the boat for several hours, he seemed to be interested in what we were doing. The whole time I saw him (several times at the surface) he was very very brown on top, almost like a sand or nurse shark, just normal colored. (Bug friggin' huge)
Eventually, he took a jig that was in the water (never seen a shark take a cobia rig - problem number 1).
Shortly thereafter, I returned to the back of the boat as the captain yelled "Fish On" and realized it was the Bull that had been near the boat. Instead of brown, he was now ENTIRELY a yellow and reddish color, his whole body. His entire demeanor had changed.
He went from "Hey, wonder what that boats doing" to "Please, please, bring me on that deck." His motion in the water ahd changed 100%, he was now stalking and wildly snapping his direction back and forth, like a human does when pacing around a room while angry. We finally brought it in, and got a picture before cutting it loose. (Yes, it still had the jig in its mouth - at least we didn't gaff it and throw it back like most sport fishers.)
Anyways - while diving near Ft. Walton beach last year, I was near a small reef-like area, I rose over the top of the thing to keep on going and about 10 feet in front of me was another Bull Shark. No big deal - seen them before - but this one saw me (or something in the general direction that I was in) and turned that same yellow/reddish color all over and made a full thrust charge towards the reef deal. I stayed as calm as I could, trying to swim to the side, and he veered off to the left of me and shot into open water. It felt like he was right beside me, but it was probably realistically 15-20 feet.
The one I saw underwater was not nearly as large as the one I had caught, but I knew what the color change meant and I really could have sworn that I was a goner. Again - it was probably not as life threatening as it seemed in my mind, but nonetheless, it was friggin' scary. I've been told the Bull Sharks here can get territorial, which I'm guessing is what happened?
Since then I've seen several sharks and while they are scary to some extent, I've never had another get within 50 feet of me.
They scare the piss out of me, but they are so cool.
