Japan Sea,and cooler temperate waters of central and northern Japan.
Oshoro Bay, western Hokkaido, Japan. February 1986, 16 mm long alive. Photo: Yoshi Hirano
Feeds on hydroids (in particular Tubularia sp. Grows to about 15mm. Although the external colour and reproductive anatomy are unknown for Bergh's original specimens, the species has been identified by subsequent workers through its possession of unique rounded anterior foot corners. The rhinophores are snooth. In colour the body is translucent white and there is a opaque white median line down the dorsal midline. In some cases this runs from the posterior tip of the body to the head where it bifurcates with a branch running the length of each oral tentacle. in other specimens the median line is only present at the posterior end of the body. The ceratal digestive gland ducts range in colour from yellowish brown to reddish brown. The opaque cnidosac is prominent and there are scattered white specks on the ceratal wall.
• Baba, K. (1987) Anatomical review of Coryphella from Akkeshi Bay, Hokkaido, Northern Japan (Nudibranchia; Flabellinidae s.l.) Venus, Japanese Journal of Malacology, 46: 151-156.
• Hirano, Y.J. & Hirano, Y.M. (1985) Preliminary study on the feeding ecology of the aeolid nudibranch Coryphella athadona Bergh, 1875, with special reference to nematocysts in the ceras. Special Publications of the Mukaishima Marine Biological Station 1985: 161-166.
Rudman, W.B., 1999 (July 17) Flabellina athadona (Bergh, 1875). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/flabatha