Opae, as you probably know, is just the general Hawaiian word for shrimp. The animals in your pictures would be the Neocaridina denticulata (might now be N. heteropoda, depending on who you consult) that were introduced to Hawaii from East Asia. Same species as cherry shrimp.
I'm not that great with Asian atyids, but I don't think these are what OP has (body form reminds me more of a Caridina from the "bee shrimp" group).
At any rate, it's not uncommon for these non-target "contaminant" species to show up in shipments of Amanos, since they're all wild-collected.
I don't mean to hack this post but so if it is Neocaridina denticulata that means they would interbreed with rili shrimp?