Amanos don't have that topline stripe. They have a more pronounced topline. They don't have the speckling on teh carapace and they don't have that drastic of a difference in gender at that size (those look like 1" or so shrimp). Amanos you cannot really tell the gender until probably about 1.25" and then its because the females have such a drastically larger body mass.
To me, those look like one of the "new" caridina coming out of Hong Kong. I have gotten several in recently labeled as vairous "algae eating shrimp" with color labels. They could also maybe be a babaulti, but their speckling makes me thing not.