I agree, Sergyal... using those identification methods can be very hard to determine a specific species of ray. Most scientists now use internal methods of identification, like counting rows of teeth. Obviously, this would be a very impractical method for hobbyist to use.
It's not as if the hobbyist would be nominating species or mis-labeling scientific names, but rather putting a 'trade-name' on a specific type of ray.. I would base it more so on pattern, tail structure, eye structure, and most importantly, collection zone. Many species of fish, especially variants, are named after their collection area. For example, the P14 - Potamotrygon sp "Itaituba" acquired that name based on the city they were exported from. A hobbyist member, Itaituba2003 *(Frank), is the one who nominated that name.. and it has definitely stuck!
