He's nice!
How big is he?
Awesome Mike. Don't lose faith because of the bad experience you are having bro, keep it up and you will be rewarded with these guys I promise.
Losing rays hits you in many cases much worse than losing other fish, maybe its because of their intelligence, they seem more like pets, shouldn't be the case but it is.
This little Marble you have is more than worth pursuing your interest in these magnificent creatures, take it from me, that pup is already showing signs of being up there with the best!
I wish you all the best!