well they are not hystrix thats for sure
if they were imported as hystrix chances are they are columbian motoro
i would need to see a close up of the tail but most motoro have a single row of hocked spikes along the tail which is why alot of people thing pearl rays are a type of motoro as they also have that form of tail spikes
cane if you look at your rays you will see what i mean motoro have one line of hocked shaped spikes the lenght of the tail other rays have spikes with no set patern
im not to sure about the colubian/peruvian motoro as they have only been imported as hystris for the last 1-2 years