Colpodaspis pusilla M. Sars, 1870

17 June, 2014.
Ardnoe Point, Sound of Jura on the west coast. 
4 mm animal at 18 m. Water temperature 11°C.
Sony NEX-5 in Nauticam housing, 18-55mm lens and 2 x Inon D-2000 flashes.

for more information about this species go to one of the links below
OPK - Opistobranquis Encyclopedia of Marine Life of Britain and Ireland Sea Slug Forum