You know, I have researched plenty into identification and I have never came across specific Duncan species. I know a lot about them do to them being, IMO
, the easiest LPS
coral to keep.
With that said, I do see a difference between An everyday Duncan and an aquacultered ORA Duncan coral. In ORA, you generally will have a purple skirt. I think there are many morphs out there, I would say you have a normal Duncan, and I would be willing to bet that the darker lines in your coral will eventually turn all green. It is a nice piece and I would make sure you hold on to it!