Trinchesia caerulea (Montagu, 1804)

20 April, 2008.
Ardcastle Jetty, Loch Fyne on the west coast.
20 mm animal with 2 others nearby at 15 metres. Water temperature 8° C.
Fuji E900 camera in Ikelite housing, 2 x Inon D-2000 flashes and 2 x Inon CU lenses.

For more information about this species go to the link below.
OPK - Opistobranquis