Trinchesia caerulea (Montagu, 1804)

1 February, 2007.
Lephinchapel, Loch Fyne on the west coast. 
A 22 mm animal on a hydroid at 14 m. One of several seen during the dive and spawn. Water temperature 9°C.
Fuji E900 camera in Ikelite housing, 2 x Inon D-2000 flashes and 3 x Inon UCL-165AD CU lenses.

for more information about this species go to one of the links below
scottish nudibranchs

 nudibranchs of the british isles sea slug forum