ID as per a Facebook post on March 5 by Gary Cobb on Nudibranch Central: "Taxonomic Update. According to work that is done by Gosliner (@tgosliner) and team Flabellina rubrolineata is only found in the Red Sea area. Animals we have been calling Flabellina rubrolineata are mostly Flabellina lotos pictured here (found commonly in the Mooloolah River, La Balsa Park, Sunshine Coast, Queensland, Australia."
-- Now on WoRMS as Coryphellina lotos.