About Favorinus tsuruganus Baba & Abe, 1964
Favorinus tsuruganus reaches a maximum total length of 25 mm. Its back and oral tentacles are opaque white, with a yellow patch located on the front of its head. The rhinophores are black, and develop three distinct collar-like swellings along their length. The cerata of this species have black tips, and their digestive gland ducts are orange — this orange duct is a distinguishing feature that sets Favorinus tsuruganus apart from related species. This species is found in Japan, occurs more rarely in eastern Australia as far south as around Sydney, and has a broad distribution across the western Pacific Ocean.
