I'm careful with tank mates, but they are all very friendly and work together.
The fire eel scares shrimp out of narrow hiding places so the ray can eat them, I swear I'm not kidding. The 3 polypterus (soon to be 6!!) are a similar type of fish and go incredibly well together.
All in all, the ray is an incredible addition to my tank and I hope to get another one today or Thursday
I'm having a tough time sexing my current ray, but I'm somewhat positive its a female. I wonder if NASIOC would let me sell the pups in MAIC classifieds