tea cups arnt an actual species, they are just young cheap rays that they dont know what to call them so they label them tea cups, as stated above they are normally reticulated rays, but sometimes they are humerosa, orbingi, peru sp, and many others, all will eventually outgrow your tank, retics will stay on the smaller size and get a max of 14-16" disk but that is without tails, and the other ones normally get at least a 24" disk