This obviously says how much you know about rays...teacup is not even a species...sand is not mandatory...teacups in general, come half dead most of the time, not easy to keep at all...instantthc;3723133; said:sry about these guys... i understand you are knew to this and I would reccomend teacup rays. they are fresh water and very easy to keep. just make sure to have sand in your tank for them to bury. Look up these if you are willing to make the effort. GL