Chromodoris fidelis
(Spotted Form)

Suborder: DORIDINA
Family: Chromodorididae


This colour form known only from northern New South Wales and southern Queensland in eastern Australia.


UPPER: Mutton Bird Is, Coffs Harbour Region, northern New South Wales, on food sponge, 12, 24mm long, March 1988. MIDDLE: Solitary Is., Coffs Harbour Region, northern New South Wales, 19mm long, March 1988. LOWER: Mutton Bird Is, Coffs Harbour Region, northern New South Wales, 23mm long, March 1988.
PHOTOS: Bill Rudman.


Chromodoris fidelis

At present I consider this to be a strange colour form of Chromodoris fidelis. It is only found in eastern Australia, from northern New South Wales up to the southern end of the Great Barrier Reef in Queensland. Like Chromodoris fidelis it has a white body with black rhinophores and gills. It has a golden yellow rather than orange border and the red line on the inner edge of the border has become a series of red spots. at the southern end of its range there is one large red spot in the centre of the mantle which I have suggested has evolved to mimic an almost identical colour form of Chromodoris splendida which only found in the same geographic locality.

There are many red and orange-spotted species of chromodorid in New South Wales and southeastern Australia. I have discussed this example of mimicry on a separate page.

• Rudman, W.B. (1985) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fidelis colour groups. Zoological Journal of the Linnean Society 83: 241-299.
• Rudman, W.B. (1991) Purpose in Pattern: the evolution of colour in chromodorid nudibranchs. Journal of Molluscan Studies, 57, (T.E. Thompson Memorial Issue): 5-21.

Authorship details
Rudman, W.B., 1999 (June 1) Chromodoris fidelis (Spotted Form). [In] Sea Slug Forum. Australian Museum, Sydney. Available from