(Linné, 1758)
Description (shell):
This limpet is almost confined to Laminaria plants where it occurs in two forms, A. pellucida pellucida on the fronds (less frequently on fronds of Fucus serratus ) and A. pellucida laevis within the holdfast.
The shell of A. pellucida pellucida is a thin, smooth, depressed cone, with apex close to, or at, anterior margin; posterior profile markedly convex (A. pellucida-drawing).
The taller and more robust shell of A. pellucida laevis has prominent concentric growth lines, giving it a ledged profile, invariably surmounted by a distinct apical region exhibiting features of the A. pellucida pellucida shell.
Size:
A. pellucida pellucida : up to 20 x 15 mm.
A. pellucida laevis : up to 20 x 8 x 10 mm.
Colour:
A. pellucida pellucida : translucent, horn-coloured, patterned with bright blue rays.
A. pellucida laevis : dull and devoid of blue rays, though it may have red rays.
Animal:
Cream coloured, tinged with brown. Mantle is fringed with long and short filaments. Tentacles are slender, eyes small.
Habitat:
Occurs intertidally on Laminaria , and occasionally on low level (LWST) Fucus serratus ; extends sublittorally to 27 m.
Distribution:
Distributed from Iceland to Portugal (Distr. A. pellucida). Also reported off Helgoland by K. Janke (Harms, 1993).