Known only from Adriatic Sea [Croatia] and around the coast of Greece [Ionian Sea, Saronic Gulf].
Brac Island, Croatia. Size approx 1 cm. Photo: Jan Prochazka
The original description was based on 3 specimens colected in Greece. Thompson describes them as having a translucent white ground colour which was overlain dorsally by a pattern of dark brown which essentially covers the whole of the dorsum except for a patch on each side alongside the eyes, the head, infront of the rhinophores, and the tips of the rhinophores. Both the dorsal and ventral surfaces of the flattened cerata are translucent white, except for a 'row of blunt, dark brown digitations'. Thompson's largest specimen was 11mm long.
From the photo from Croatia, it seems the most distinctive feature of this species is the translucent white colouration of the cerata and the row of rounded papillae along the ceratal tip. The Croation specimen differs from Thompson's Greek specimens in having a brown line edging the tip of each ceras, rather than having brown tubercles.
• Thompson, T.E. (1988) Eastern Mediterranean opisthobranchia: Oxynoidae, Polybranchiidae, Stiligeridae (Sacoglossa). Journal of Molluscan Studies, 54: 157-172.
Rudman, W.B., 2003 (October 7) Cyerce graeca Thompson, 1988. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/cyergrae