Trinchesia caerulea (Montagu, 1804)

26 April , 2007.
Lephinchapel, Loch Fyne on the west coast. 
15 mm animal at 16 m. One of several seen with 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 the link below.
OPK - Opistobranquis