It was a risk that i took. He was living w the rays for 2-3 mos. Rays were 8,10,11 inches diameter and the Geo was a puny 6 -7 inches. Sucks. Cant predict my rays.. they ate a 9-10 inch black aro last year.
As far as i know they would chance on the fish thats resting on the bottom.
They would gently slide beside them.. gently embrace them with their disc
and once they blanket the victim thats it.. they get chewed to death...
All the killings happen overnight when the fish are possibly resting.
I have heard of other fish dying of because they get stung but they were accidental.
A rays stinger is at the base of its tail and is for defensive purposes only. They don not hunt with their stingers it would be hard and impractical because they would have to spin around to sting the fish. When they do sting it mostly by mistake.