Bangaii Cardinals

[Enigma]

I purchased a pair of Bangaii Cardinals three weeks ago.

One of them has disappeared. Not on the floor. No ammonia spike in the QT. Just GONE. I hate it when fish disappear (I had a clown disappear a couple of months ago).

Anyhoo . . . the Bangaii I have left appears to be female (rounded on the belly, versus very square). She is a voracious eater: brine, mysis, pacifica plankton, Arctica-Pods. If it is meaty she'll eat it. She isn't timid, either. She aggressively chases food, though she plays nicely with the other fish in the QT (Clowns, Chromis, Signal Goby). She is about 1/2 of full grown.

I'm pretty sure the one that pulled the vanishing act was male, and he was very timid. I haven't seen him in a week, so I'm pretty sure he really is gone.

I'm leaning towards attempting to find another partner for the Bangaii I have. Does anyone have any recommendations as to how I should go about this? I have yet to see a lone Bangaii in a tank at a LFS. I don't want to take another's mate.