Pleurobranchus membranaceus (Montagu, 1815)

2 May , 2011.
South Gortein, Loch Fyne on the west coast. 
95 mm spawning animal at 14 m. There were many animals mating , spawing and feading and spawn spirals between 12 - 14 m. Water temperature 9°C.
Canon S95 in Ikelite housing.
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