Upper: Coffs Harbour region, northern New South Wales, November 1990. AM C164521. Lower: Jibbon Head, Port Hacking, Sydney, NSW, Nov. 1981. Photos: Bill Rudman.
Note added 4 July 2007: The name is changed today from C. flavicostata to C. flavicostatum - see message #20101.
This species has often been identified as Miamira magnificum Eliot, 1910, but there is considerable confusion surrounding the identity of that species. Until now I have, like Baba & Hamatani (1974), considered all the various coloured forms of 'Miamira' to be part of one variable species of Ceratosoma [see message #19853]. As outlined in a separate message [#19854] I am now recognising Ceratosoma sinuatum and Ceratosoma flavicostatum as separate species, and separating a few western Indian Ocean animals as possible specimens of C. magnificum.
Ceratosoma flavicostatum usually has a broad whitish margin to the mantle and the rest of the mantle is a reddish brown or even purple with orange rounded ridges. The rhinophores usually lack white markings, but the gills are edged with opaque white lines. The front of the mantle does not have a prominent central lobe. In both this species and C. sinuatum there can be up to three large tubercles in the dorsal midline between the gills and the rhinophores. If present, the most posterior one, just in front of the gills, is the longest, often standing much taller than the gills.
C. flavicostatum was first described from Japan and has been reported since from many parts of the tropical western Pacific. The name flavicostatum [= yellow ridges] indicates one of the most obvious characters of this species.
Baba, K. (1940) Miamira flavicostata n.sp., a nudibranchiate mollusc from Amakusa, Japan. Zoological Magazine, Japan 52(6), 239-240.
Baba, K & Hamatani, I. (1974) On the synonymy of Miamira sinuata (van Hasselt, 1824) from Japan (Nudibranchia: Dorididae: Miamirinae). Venus, The Japanese Journal of Malacology 33 (2, August), 81-84.
Eliot, C.N.E. (1910) Nudibranchs collected by Mr. Stanley Gardiner from the Indian Ocean in H.M.S. Sealark. Reports of the Percy Salden Trust Expedition to the Indian Ocean in 1905, under the leadership of Mr. J. Stanley Gardiner, M.A. Transactions of the Linnean Society, Zoology, series 2, 13(2), 411-439, Pl. 25.
Valdes, A. & Gosliner, T. (1999) Reassessment of the systematic status of Miamira Bergh, 1875 and Orodoris Bergh, 1875 (Nudibranchia; Chromodorididae) in light of phylogenetic analysis. Journal of Molluscan Studies, 65:33-45.
Bill RudmanAuthorship details
Rudman, W.B., 2007 (April 30) Ceratosoma flavicostatum (Baba, 1940). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/ceraflav
Re: Ceratosoma flavicostatum feeding
From: Teresa Zuberbühler, June 10, 2008
Coincidental occurrence of Ceratosoma flavicostatum & S. ornatum
From: David Mullins, September 6, 2007
Re: Ceratosoma flavicostatum feeding
From: Leanne & David Atkinson, July 5, 2007
Ceratosoma flavicostata feeding
From: Danny Van Belle, April 30, 2007
Ceratosoma sinuata from Queensland
From: Gary Cobb, July 14, 2003
Sprinting Ceratosoma sinuata
From: Sabine Noack, October 22, 2002
Ceratosoma magnifica trailing
From: Ákos Lumnitzer, January 10, 2002
Ceratosoma sinuata from Indonesia
From: Ken Knezick , January 16, 2001
Re: Left-handed Ceratosoma sinuata
From: Donata P. & Akos L., October 27, 2000
Ceratosoma sinuata - magnifica form
From: Akos L. & Donata P, October 25, 2000
Ceratosoma sinuata - how long-lived?
From: Donata P. & Akos L., October 19, 2000
Miamira from New South Wales
From: Scott Jamieson, April 13, 1999
Photo of Miamira at Point Cartwright
From: Wayne Ellis, May 26, 1998