For a long time I was under the impression all cownose ray species in captivity were the nominate Atlantic cownose ray or Rhinoptera bonasus. But recently I have discovered the Aquarium of the Pacific: Pacific Cownose Ray has Pacific Cownose ray or Rhinoptera Steindachneri. So now I have to ask how many different species of cownose rays are in captivity and how common are they?
At least in North America, by far the norm is R. bonasus. I would guess that aquariums on other continents lean towards their native Rhinoptera species but I do not have any actual confirmation.
Looking at ZTL: Cownose ray (bonasus) is also by far the most common species kept in Europe (at 42 institutions). The second most numerous (7x) is Oman cownose ray (R.jayakari) - wild-caught individuals get regularly into legal trade here. Next is Javanese cownose ray (6x). And then the rarest one - Lusitanian cownose ray (marginata) kept only at Valecia.
The Australian Cownose Ray, R. neglecta, is the usual species here in Australia (the cownoses at Cairns Aquarium are this species). Javanese Cownose Ray, R. javanica, is also kept, I have seen it at Osaka Aquarium and Tokyo Sea Life Park.