Homoiodoris japonica
Bergh, 1882

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Dorididae

DISTRIBUTION

Japan and coast of China.

PHOTO

Hong Kong, 1983. Photos: B.W. Darvell.

Little is known about this species, in fact from the many photos on the web it seems that more than one species has been identified as Homoiodoris japonica. I am assuming the animal illustrated here is correctly identified. It is widespread throughout Japan and there are records from Korea and Hong Kong. It is relatively large, reaching 60 -80 mm in length and is covered with many tubercles which vary greatly in size but have a characteristic shape, with a narrow basal 'stalk' and an inflated body which narrows to a rounded nipple-like tip which is usually marked with a purplish or dark brown patch.

The rhinophore sheath has a pair of 'valves at the edge as well as scattered, small rounded tubercles.

  • Baba, K. (1949). Opisthobranchia of Sagami Bay. p.66, 152 Pl. XXV, figs. 91-92, text fig. 81  Toykyo : Iwanami Shoten
  • Bergh, L. S. R. (1882) Beitrage zur kenntniss der japonischen Nudibranchien. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 31: 219-250.
  • Hamatani, I (1962): Notes on veligers of Japanese opisthobranchs. (5). Publications of the Seto Marine Biological Laboratory 10(2, December), 283-292. 
Authorship details
Rudman, W.B., 2007 (June 19) Homoiodoris japonica Bergh, 1882. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/homojapo

Related messages


Homoiodoris japonica from Hong Kong

June 19, 2007
From: Bill Rudman


I am posting these photos of Homoiodoris japonica in response to Felix Poon's message [#19988] about this species.

The photos were taken by Dr B.W. Darvell during the Hong Kong Workshop in April 1983. Unfortunately I have no further details concerning these photos but they show the typical shape of the body and tubercles very well.

Bill Rudman

Rudman, W.B., 2007 (Jun 19) Homoiodoris japonica from Hong Kong. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20040

Homoiodoris japonica from Hong Kong

June 19, 2007
From: Felix Poon

Dear Doctor Rudman,

Could you please identify this species? It has many green warts. Its egg ribbon is orange-yellow.

Locality: Shek Ngau Chau, Hong Kong,  6 May 2007, On rock at 7 m. Length: 8 cm. Photographer: Felix Poon

Thanks
Felix Poon

ifex@hotmail.com

Poon, F., 2007 (Jun 19) Homoiodoris japonica from Hong Kong. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19988

Dear Felix,
This is what I have identified as Homoiodoris japonica, but I see on the web that at least two species have been given this name. There is little scientific literature on the species but I am pretty sure yours is the 'correct' Homoiodoris japonica. Although hard to see in your photos there is a brownish purple patch at the tip of the tubercles.

I suspect the red sponge is its food, as in Japan it has been reported to be found near a red sponge called Halichondria japonica but I can't confirm the sponge identification.

Best wishes,
Bill Rudman

Rudman, W.B., 2007 (Jun 19). Comment on Homoiodoris japonica from Hong Kong by Felix Poon. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19988