Rostanga sp. from Turkey

Dear Baki,
Thanks for this nice photo showing egg-laying. From my reading of the literature there are only two species at present accepted from the Mediterranean, R. rubra and Rostanga anthelia. R. anthelia sems to be known only from very small, possibly juvenile specimens, so it is not clear wheher the described colour pattern with many large white patches a round the edge is a juvenile feature or will also be found in adults.

R. rubra is ceratinly a possibility. If you look carefully between the rhinophores in your photos there is a trace of white. The shape of the egg ribbon, and the size of the eggs is similar to that described for R. rubra but the colour is not. Its eggs have been described as white or pale pink but never bright orange. As to the flattened appearance of animals in Michel Barrabés' photos. It is quite usual in Rostanga to find animals becoming very flattened when they are on their food sponge but quite raised when crawling on other substrates.

The only sure way to find out what you have would be to look at the anatomy - I still have difficulty identifying specimens of species I am reasonably familiar with. I look forward to comments from peoplemore familiar with European species of this genus. I will temporarily put your message on the R. rubra page more more administrative convenience than beacause I am convinced it is that species
Best wishes,
Bill Rudman