Are Doris odhneri and Archidoris odhneri synonyms ?

Dear Ron,

As I have discussed a number of times I have some difficulties with parts of Angel Valdés's (2002) analysis of the cryptobranch dorids. One of these difficulties revolves around his examination only of the type species of each genus [see message #19925]. Even if his analysis does prove to be correct and we synonymise many genera - for example Archidoris is a synonym of Doris - it does not necessarily follow that all the species that previously were placed in Archidoris should be moved to Doris until their anatomy is re-examined. For example both A. montereyensis and A. odhneri have tripinnate gills so should never have been in Archidoris in the first place because one of the characters of the type species was unipinnate gills. The branching of the gills may turn out to be unimportant but it does illustrate the point that all the species in the genera which Valdés has synonymised need to be examined before being reallocated to different genera to see where they really should go. Otherwise we are just compounding existing errors.

This also is a problem arising from Valdés & Gosliner's, 2001 paper [see message #16240] where Anisodoris and Diaulula were synonymised but species like Anisodoris nobilis [now placed in Peltodoris] were essentially left in limbo.

Which brings us back to Archidoris odhneri. Dave Behrens (2004) has moved both A. montereyensis and A. odhneri to Doris on the grounds they both have rounded tubercles without protruding spicules. I don't know if that is sufficient justification. In Angel Valdes earlier message [#16240] he says:
"It would be a very time consuming task to review all species of cryptobranch dorids and try to determine their taxonomic placement in light of the results of our phylogenetic hypothesis. So we preferred to provide diagnoses for all genera and leave for future research, or our colleagues research, to determine the taxonomic placement for all those hundreds of species names. When we wrote the diagnoses we were conscious that many of them where too inclusive or exclusive and would need further work after examining real animals."

Unfortunately that approach has left all the species names, which are not types, in limbo, until they are individually examined. It also raises one of my objections to their approach. How can they define genera before they have looked at all the species? Surely we can only differentiate between generic characters and species characters after we have compared groups of species which seem to cluster together? It also leaves the Forum in limbo as well - should I continue to use the old names or make a guess on a new combination? Since American west coast colleagues have started to use Doris for these species when writing to the Forum I have decide to leave their usage unchanged, but have decided to retain Archidoris until the species have been properly reviewed - otherwise I may be just transferring them from one wrong genus to another. It's not a very satisfactory solution but I can't see a good alternative.

• Behrens, D. W. (2004) Pacific Coast Nudibranchs, Supplement 2. New species to the Pacific Coast and new information on the oldies. Proceedings of the California Academy of Sciences 55: 11-54.
• Valdés, A. & Gosliner, T. M. 2001. Systematics and phylogeny of the caryophyllidia-bearing dorids (Mollusca, Nudibranchia), with the description of a new genus and four new species from Indo-Pacific deep waters. Zoological Journal of the Linnean Society, 133: 103-198
• Valdés, A. (2002) A phylogenetic analysis and systematic revision of the cryptobranch dorids (Mollusca, Nudibranchia, Anthobranchia). Zoological Journal of the Linnean Society 136: 535-636.

Best wishes,
Bill Rudman