Hypselodoris rudmani? from Oman

Dear Brian,

Your animal certainly fits the description of H. rudmani, but I don't claim to be an expert on identifying it. It certainly looks very similar to Colin Ogden's photos [message #17554] but as I say in a later message [#19989], H. rudmani has similarities to H. sagamiensis. One feature which is very clear in your photos is the row of inverted triangles along each side of the mantle which are slightly darker than the background colour of the rest of the mantle. One character I used to think was unique to H. infucata was similar triangles which appeared darker than the background colour because they were translucent rather than pigmented. If this is H. rudmani then that species is a very good mimic of H. infucata, or it is in fact a very white pigmented colour form of H. infucata. Clearly I would prefer it to be a good species, but I still think we have some sorting out to do in this colour group of species.

For example in an earlier message from Teresa Zuberbühler [#21614] she has a photo showing a group of animals feeding on a sponge. I identified them as H. infucata but was puzzled by the spots on the gills of the largest specimen which are characteristic of H. kanga. On relooking at that photo I can see that the animal with spotted gills does not have the characteristic inverted triangles while all the others do. On reflection it looks like Zubi's photo shows both H. infucata and H. kanga feeding together. Another puzzle is Binaymin Koretz's photo [message #15795] of a strange colour form of H. infucata from the Red Sea. Perhaps this is H. rudmani?

As you can see, I am not a confident identifier of H. rudmani at present. No doubt as we learn more about these species it will become clearer, but at present I am somewhat cautious.

Best wishes,
Bill Rudman