Their care is pretty much the same as the other Potamotrygon species, they will accept a fairly wide range if pH and hardness levels as long as they are constant ( its the fluctuations that stress and kill rays )
They grow to be the same size as Motoros so they are not small fish ( will probably max out at 24" )
They are fairly forgiving rays and settle in pretty well compared with some
we feed ours on prawn, mussel, cockle and live earthworms
And looking at male development i.e claspers then I have to say it seems to be reasonable.
My male hystrix has fully developed claspers at 9", my orbi has developed claspers at 9" and they both get to 14". The Yepezi has not started to develop his claspers and he is 10" so he has a fair bit of growing to do yet. Either that or he is a pee-wee