Gymnodoris amakusana
(Baba, 1996)

Suborder: DORIDINA
Family: Gymnodorididae


Known from western Pacific from Japan to New Caledonia, and Western Australia.


UPPER: Mir Bay, Hong Kong, 3-5m, April 1983, 15mm long, PHOTO: Brian Darvell.
LOWER: Koumac, New Caledonia, October 1993, 12mm. PHOTO: Bill Rudman.


Gymnodoris striata

Specimens previously considered a colour form of Gymnodoris striata, without orange longitudinal lines on the dorsum between the rhinophores and the gills, have recently been considered a separate species, G. amakusana, by Baba (1996). I can find no anatomical reasons to support this proposal. As I illustrate here, even the colour pattern of the two animals here varies, one having an orange line, behind the gills, and the other having orange-lined gills.

•Rudman, W.B., Darvell, B.W. (1990). Opisthobranch Molluscs of Hong Kong: Part 1. Nudibranch Families; Goniodorididae, Onchidorididae, Triophidae, Gymnodorididae, Chromodorididae. Asian Marine Biology, 7: 31-79.
•Hamatani, I. (1995) A new record on Analogium striatum (Eliot, 1908) (Opisthobranchia: Nudibranchia: Gymnodorididae) from southwestern Japan. Venus, (Japanese Journal of Malacology), 54(3): 179-183.
•Baba, K. (1996) Taxonomical change for Gymnodoris striata of Baba, 1937 (Nudibranchia: Gymnodorididae) from Amakusana, with a re-description based on some additional specimens from Toyama Bay, Japan. Venus, (Japanese Journal of Malacology), 55(2): 91-95.

Authorship details
Rudman, W.B., 1999 (September 24) Gymnodoris amakusana (Baba, 1996). [In] Sea Slug Forum. Australian Museum, Sydney. Available from