Dear Jackie and Glen,

I will agree the "rearing" is unusual in this group of dorids. Rearing is common amoung phanerobranch dorids (those that cannot withdraw their gill), as discussed in my book - Nudibranch Behavior.

Although we will never know for sure, the behavior is thought to be a way for the slug to elevate itself above the substrate in search of chemical clues for its favorite prey.

Best wishes,
Dave Behrens

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

Hi Jackie and Glen,
I tend to agree with you. Thanks for sharing

Best wishes,
Dave Behrens

Thanks Dave,
I guess after just trying to sort out published sponge indentifications for my review of feeding in the chromodorids recently, I have been shocked at how often sponges are misidentified in the literature. Sometimes it is because a species was misidentified 100 years ago and the error has been repeated over generations, sometimes it is a recent error by a book publisher in search of a name, but in most cases it is a reflection of how few sponge taxonomists there are and how much work still needs to be done.

Often its not just a simple misidentification, but a complicated nomenclatural or taxonomic problem - for example a species may have been originally placed in the wrong genus and the error has never been corrected, so even though it has always been called Tethya xus for example, it may really be in a different family. That is not to say that the books you cite are all full of errors - I have no idea .. but I suspect that if sponge taxonomy on the Nth American west coast is like most sponge taxonomy, then there is a possibility that identifications based on 'tradition' and 'common usage' and not based on recent research and revisions could prove to be wrong. Which leaves us non-experts with a problem.
Bill Rudman

Dear Jan,
There is no ambiguity in this observation! It is definitely feeding. I would be grateful if anyone with a knowledge of the sponges of the area could confirm the identity of the sponge. It looks more like a species of Halichondria than a species of Haliclonato me

Thanks Bruce,
I am pretty sure this is Archidoris odhneri. If it isn't I am sure someone will let us know
Best wishes
Bill Rudman

Thanks Clinton,
Your animals certainly look like Archidoris odhneri but I am too much of a coward to agree or disagree with your identification of the brown-spotted yellow animal in the top photo.
Best wishes
Bill Rudman

Thanks Clinton,
For these two to be mating, they would have to have their right, rather than their left sides together. I suppose its possible the photo is reversed, but even so I don't know why they would me sitting on top of egg masses to mate. The other, and more likely possibility is that they are both laying their eggs close together for some reason.
Cheers,
Bill Rudman