Flabellina rubrolineata (also Coryphellina rubrolineata) varies strongly in size and colors. They can be found everywhere in Southeast Asia. The specimens that I found were as small as 5mm to as big as 40mm. Like mainly all aeolids, it has the ability to store the stinging cells from cnidarians eaten.
Size: 4cm
Depth: 15m
Divesite: several
Country: Indonesia