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Red Rockcod Scorpaena cardinalis and nudibranch
The Red Rockcod with a nudibranch Ceratosoma sinuata on its head.
When Akos Lumnitzer told us that he had photographed a Red Rockcod Scorpaena cardinalis with a nudibranch on its face we were a little sceptical. So he brought us the photographs to prove it.
The top image shows a 20cm long Red Rockcod, with a 5cm long nudibranch, Ceratosoma sinuata (van Hasselt, 1824) on its head.
The lower image shows a closer view of the nudibranch (not attached to the fish). Both photographs were taken at a depth of 15m at Shark Point, Sydney, New South Wales.
The nudibranch Ceratosoma sinuata.
Ceratosoma sinuata feeds on sponges, so it is most likely that the nudibranch was simply moving across the bottom and the Red Rockcod was in the way.
Another species of nudibranch, Gymnodoris nigricolor, has a unusual association with several species of fishes. Bob Bolland of University of Maryland, Asian Division, has recorded this species on the dorsal fins of Japanese gobies. The reason why the nudibranch has this association with the fishes is unknown.
More details on the Red Rockcod.
More details on the Ceratosoma sinuata.
More details on nudibranch symbiotic associations.
View an image of a different species of nudibranch on the head of a scorpionfish.
Further Reading
For the Red Rockcod:
- Kuiter, R.H. 1993. Coastal Fishes of South-Eastern Australia. Crawford House Press. Pp. 437.
- Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
- Poss, S.G. in Gomon, M.F, J.C.M. Glover & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
For the nudibranch:
- Coleman, N. 1989. Nudibranchs of the South Pacific. Neville Coleman, Springwood, Qld. Pp.64.
