Up to 15 mm long when fully grown, this species is easily identified by its translucent amber shell with brilliant blue spots running in lines across the top of the shell.[3]
The blue-rayed limpet lives primarily on Laminaria (kelp) in strong flowing water[4] but also on Fucus serratus on the lower shore, down to about 30 m.
The larvae of this limpet species settle and metamorphose on the algal frond. Here it feeds on its host’s tissue using its radula, leaving small depressions in the frond.
As the limpets grow larger, they move down the stipe of the seaweed towards the holdfast, where they establish themselves by excavating a depression. This can weaken the holdfast, eventually resulting in the seaweed being dislodged by storms. The seaweed is often washed ashore, with the blue-rayed limpets still in place.
^Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 180-213
^Campbell, A.C. 1984. The Country Life Guide to the Seashore and Shallow Seas of Britain and Europe. Country Life Books. ISBN0-600-34396-0
^Lewis, J.R. 1964. The Ecology of Rocky Shores. The English Universities Press Ltd.