That's a Bandtail Puffer (Sphoeroides spengleri). I have been diving for 25 years and run into these all through the Caribbean, Mexico, and up along the Carolinas. They're poisonous to eat and they can inflate if harassed. They are some aggravating bait stealing buggers. They're not endangered & I don't know what other animals eat them...not me, I know that much.

Jim