Kevin, sorry to here that you lost the ray, but as Paul said, he lost one too.
They are very touchy when it comes to the water they are in, and any slight alteration could kill; not enough O2, NH3 or NH4 levels, temp....you getthe picture with out me rambling on about it. Good luck with the others. Depends on if the JD are both males, if they are they may fight for territory. Do both of the JD have long dorsal fins or is one of them blunted? If they are the same i would seperate, if not, then you have a male and a female, the little lip lock is a form of affection and given the right water conditions, you could have a few more JD running around. Good luck in either case.