Gastropteron rubrum

Bülent Kılınç Spanish Dancer Gökçeada Turkey Nikon d800E 60 mm f18 1/200 ISO 100 Z240 Strobes

Jenny Wong Spanish dancer? Lot difference from the one i used to saw!

Krzysiek Ro Gal Beautiful Lady :-)

João Pedro Silva Looks like a sea hare, not a spanish dancer which is a common name associated with a nudibranch (Hexabranchus sanguineus) not occurring in the Mediterranean (at least yet...).

João Pedro Silva It actually a cephalaspidean, a head shield slug: Gastropteron rubrum. More info at the Sea Slug Forum: http://www.seaslugforum.net/gastrubr.htm

João Pedro Silva This goes to show the use of common names in these animals is often misleading. Here's a post by Bill Rudman on the subject of using common names for sea slugs: http://www.seaslugforum.net/find/common

Ron Silver Use of common names period is misleading! Long live binomial nomenclature - even if it is constantly changing. LOL

João Pedro Silva Even then, Ron Silver. While writing the field guide on the Sea Slugs of the Algarve we had to do many changes: the Chromodorididae were all revised a few months before we delivered the manuscript.

Ron Silver I know. The use of genetic testing is basically rewriting the science (art?) of classification and certainly seems to be tolling the death knell of the 'lumpers vs. splitters' arguments of days gone by!

João Pedro Silva But this photo and the consequent comments have shown there are some exceptions. This was not a case of simply using a common name for several unrelated species: no one uses "spanish dancer" for Gastropterum rubrum. It is a case of misidentification. There are 3 or 4 common names in some languages which can be used to positively identify a species. One of those cases is precisely "spanish dancer" as everyone knows it refers to Hexabranchus sanguineus. Other is the Mediterranean and Atlantic Peldororis atromaculata which is called in several latin languages (but not french) "small cow" (and variations on the same theme). When someone tells me he or she has seen a small cow I can be sure they have seen Peltodoris atromaculata. Most of the other names are useless an can be used to refer several unrelated species even within the same distribution range (let alone in different oceans...).

João Pedro Silva I think there are "lumping" and "splitting" periods and even overlapping sometimes. And DNA analysis (actually, some scientists consider the gene loci used so far may not be good enough) may provide information which goes both ways. For instance, the latest revision on Aeolidiidae hints on Aeolidia papillosa actually being a complex of 3 species... and the control specimen used (from other families) hint towards Flabellina confusa and Piseinotecus gaditanus being the same species (I think synonymy was not proposed because it was out of the scope of the paper). http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0063000

Ron Silver I surrender! :-D

Bülent Kılınç thanks a lot for the information you gave us Joao Pedro Silva and I will inform the local dive guides in Gökçeada Turkey.I was told that this critters have not been seen around there before and a kind of Spanish Dancer.

Bülent Kılınç I change the name of this critter as Gastropteron Rebrum

João Pedro Silva Glad to be of help, Bülent Kılınç!

João Pedro Silva Although this species is also present in the Atlantic, we haven't included it in our field guide. If you're comfortable reading french I recommend you a very comprehensive field guide for the Mediterranean with 171 species of sea slugs: "Des Limaces de Reve", by Sandrine Bielecki, Gilles Cavigneux, Jean Michel Crouzet and Sylvie Grall. http://www.deslimacesdereve.com/ Although it's only 3 years old there have already been some changes in the nomenclature so it may be worth to check with WoRMS for the current valid names.

Fabio Strazzi nice shot