I took these photos on July 17th, 2005 in my hometown Istanbul / Turkey near Prince's Islands. There was apparently a gathering and the nudibranches were rushing to a place to join a party .
I think they are of Jorunna species but need help for exact identification.
Best Regards,
Aziz T. SALTIK
Hi Aziz -- I think most of us tend to concentrate on other regions so it's hard for us to come up with eastern Mediterranean names. Why don't you try contacting Orhan Aytur, an excellent photographer & nudibranch lover from Turkey? His web page (with 2 galleries of nudi pictures) is at http://www.ee.bilkent.edu.tr/~aytur/ And if he has recommendations of guide books or web sites for your region be sure to let us know!
Cheers, Leslie
Another site you may wish to search in for ID is the seaslug forum.