Booger - My input is based on what I've seen from working with them. Individual rays will be less active, feed less, tend to have physical issues alot sooner and over all just don't do as well as rays kept in groups. Granted, I've only raised a few hundred FW rays. But I've spent alot of time watching and documenting almost anything one can observe to see how to guide the rest of the professional keepers as to what would be best for keeping them in captivity.
These fish are highly social animals and respond very well to things that would be considered "mental enrichment". Though, I agree they are HIGHLY food motivated animals. There are several keepers out there working on target training and station feeding to disapate some aggression seen during feeding time in large groups (groups over 30+ rays).
