Vayssiereidae - further thoughts

April 20, 2000
From: Alexander Martynov

Dear Bill,

Here are my comments and picture on the recent Forum's discussion on Vayssiereidae. Please, please excuse my English. I am not very experienced.
Yours sincerely
Alexander

Subject: New thoughts on the genus Vayssierea.
For a long time our understanding about the family Vayssiereidae has been unclear. The family consists only two genera, but their distinguishing features are hardly understandable, and the genera have so few species - but how many really?... Recently we have new excellent data on the radula of Vayssiera caledonica, and now the radical suggestion for Vayssiereidae - only one genus and only one species from South Africa to Japan.

When I look at Collingwood (1881), I found that figures of Trevelyana felis on the color plate undoubtedly belong to Vayssiereidae. However, are the differences between radula of Japanese Okadaia elegans Baba, 1930 and Vayssierea caledonica Risbec, 1928 really sufficient to keep them separate? I have studied the radula of V. elegans from Peter the Great Bay and vicinities, Japan Sea and from the Pacific side of Kunashir Island (Kurile Islands) . All these radula always have no central tooth ( I used only light microscop - but I don't think I missed anything) and, that, more remarkable and important - denticles on the first lateral teeth are short, and in general like figures in a paper of Baba (1937). Vayssierea caledonica, from new SEM images in Southern Synthesis and on the Forum, always possesses a rudimentary central tooth and relatively long denticles on the first lateral tooth (despite what the drawings of teeth of Vayssierea caledonica in the first description made in Risbec's characteristic elongated manner, the long denticle on the first lateral are more like the recent SEM image, than Baba's pictures).

It is a clear difference between the species, which I can't ignore. In this light, taxonomic placement of Vayssierea felis became again unclear, because ther is no data on its radula. Both V. caledonica and V. elegans can theoretically inhabit the Chinese coast, where V. felis was found. Thus, the name V. felis can't simply be applied to all Vayssiereidae. Only a study of the type material, if it exists can solve the problem.

It is interesting to note the words of Baba (1937: p 149):
"Both the present species and V. caledonica Risbec differ much from Fucola rubra Quoy & Gaimard in having a pair of separate rhinophores a short distance behind the anterior end of the head (in Fucola rubra the rhinophores are connate, lying at the extreme anterior end of the head). It is suggested here that Trevelyana felis Collingwood, though regarded by Collingwood himself as an immature species of Trevelyana (Gymnodoris) and by Pruvot-Fol (1933, 1934) as belonging to the little known genus Fucola, might be a tiny, gill-less, scarlet-tinted Dorid, closely allied to either of the species, V. caledonica Risbec or O. elegans Baba."

To reach a conclusion, it is necessary to reinvestigate of the radula of vayssiereids by SEM from all known main localities and also, as far as possible, type material V. caledonica, V. elegans, V. cinnabarea (Ralph, 1944) . Before this, Vayssierea caledonica and V. elegans it is only species that really can to understand. V. tecticardia (Slavoshevskaya, 1971) is junior synonym of V. elegans. Still unknown reproductive system of type species of genus Vayssierea - V. caledonica. From external appearance and radula, genus Okadaia can be referred to the synonymy of Vayssierea, as already suggested by Bill Rudman on the forum. And did you confirm from your study the presence of ciliated 'mamelons' around anus of V. caledonica? These 'mamelons' were found by Risbec, and regarded by Baba as rudimentary gills, and one of differences of Vayssierea from Okadaia.

This situation with species of Vayssierea is for me like in the genus Berthellina - all orange externally, but different internally (Cervera, Gosliner, Garcia-Gomez, 1999). Interestingly, the earliest book, where I found combination Vayssierea elegans (Baba, 1930) is Higo, Goto, 1993 - A Systematic List of Molluscan Shells from the Japanese Is. and the Adjacent area. I regret, I don't know the source of the list of Nudibranchia in that checklist. Probably they used consultations of Kikutaro Baba or his entire list?

The family Vayssiereidae from it's birth, didn't had a normal home - Collingwood thought that Trevelyana felis was only a juvenile without gills. Risbec placed Vayssiereidae in the Sacoglossa, Ralph created a new genus near to the pelagic Phyllirhoidae. The radular morphology of some Gymnodoris and Vayssierea perhaps suggests that Vayssiereidae is a reduced descendant of the Gymnodorididae. Baba (1930) placed his Okadaia in the family Polyceridae s.l. Vayssiereidae is a family of dorids, but their relationship is unclear.

Alexander Martynov
Zoological Institute,
St.Petersburg
Russia

martyn@AM3963.spb.edu

Martynov, A., 2000 (Apr 20) Vayssiereidae - further thoughts. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2298

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