Japan and Hong Kong.
PHOTO: A. Hong Kong, April 1983, AM C139205. B. Ping Chau (S), Mirs Bay, 4-10 m. 20 April 1983, AM C139187. C. showing prominent median ridge on posterior foot. Hong Kong, April 1983, AM C139205. D. 5 specimens, Round Is. (W), Mirs Bay, 3-6 m. 14 April 1983, AM C139186. PHOTOS: B.E. Picton.
The mantle is ovate with the posterior end of the foot extending behind the end of the mantle. A distinctive feature is the distinct middorsal ridge on the posterior end of the foot. The mantle has small tubercles and the five or six gills are attached in a common pocket. Diaphorodoris mitsuii was originally recorded from southern Japan but the few specimens reported from there have been bright yellow with a submarginal orange-red band on the mantle and the foot. The gills and rhinophores are yellow. A few specimens with this yellow colour form have been found in Hong Kong but the most common form has a white body with the submarginal orange-red band and a bright yellow band at the edge of both the mantle and the foot. The gills and rhinophores are white.
One white specimen also has a yellow line, bordered with red, on the median ridge of the foot and the rhinophore lamellae are red. These all appear to be colour varieties of the one species. This species grows to about 8 mm long and most probably feeds on encrusting colonial bryozoans.
Rudman, W.B. & Darvell, B.W. (1990) Opisthobranch molluscs of Hong Kong. Part 1. Goniodorididae, Onchidorididae, Triophidae, Gymnodorididae, Chromodorididae, (Nudibranchia). Asian Marine Biology, 7: 31-79
Rudman, W.B., 2001 (July 5) Diaphorodoris mitsuii (Baba, 1938). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/diapmits
Diaphorodoris from the Red Sea
From: Binyamin Koretz, March 27, 2009
Re: Diaphorodoris mitsuii ? from Indonesia
From: Colin Ogden, July 18, 2008
Diaphorodoris mitsuii ? from Indonesia
From: Francis & Pirjo Pellet, July 15, 2008
Diaphorodoris mitsuii from Tasmania, Australia
From: Bill Rudman, August 18, 2006
Diaphorodoris mitsuii from New South Wales, Australia
From: Leanne & David Atkinson, August 18, 2006
Diaphorodoris mitsuii from the Yellow Sea
From: Dong Bum Koh, August 17, 2006
Parenthesis around author's name
From: Dong Bum Koh, January 17, 2006
Diaphorodoris mitsuii from South Korea
From: Dong Bum Koh, August 23, 2005
White form of Diaphorodoris mitsuii from Japan
From: Nishina Masayoshi , August 31, 2001
Diaphorodoris mitsuii from Hong Kong
From: Bill Rudman & Brian Darvell, August 5, 2001
Diaphorodoris mitsuii from Sagami Bay, Japan
From: Nishina Masayoshi, August 5, 2001