To be honest they could be any one of the small brown rays species, i'm not expert enough to tell them apart.
There is a species called reticulatas. Orbiginyi has been reclessified as retic CFC. And yes from the pics posted they are retics easy way to tell a retic is the length of its tail.
Given up keeping fish, can still post though
when my fish house is done this summer hopefully the biggest tank will be a 72 x 36 x 24 and would love for it to contain a pair of the smaller rays and id love an Asian aro but doubt it would be big enough!
so this is an interesting thread for me!
David