Opisthobranch of the Week Data
Phyllidia polkadotsa is considered to be very rare on Okinawa as I have seen and collected a total of only three individuals. The featured individual was found crawling on top of coral rubble in an open expanse of mixed sand and coral rubble. All three collected individuals were found at the same dive site, Seragaki.
David Brunckhorst in Australia has kindly furnished identifications for members of the family found on Okinawa, via digitized scans sent to him by email. In reference to P. polkadotsa, David writes that he has never seen specimens with so much white, usually the dorsum is bright yellow-orange with black spots. He feels the scanned slides from the three separate individuals could possibly be a color variation; he goes on to say that it's the only Phyllidia he knows of having the 2 sharp ridges as the three Okinawa specimens exhibit.