Onchidoris muricata (Müller, 1776)

12 April, 2003.
Humla Rock SW of the island of Canna on the west coast. 
Water temperature 10° C. At 5 metres, two of several animals found on the kelp browsing on the bryazoan Membranipora membranacea.
Nikon 90SX with 105mm lens in Subal housing and housed SB26 flash.

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

nudibranchs of the british isles sea slug forum