Shell elongated, the sides compressed so that the opening is concave, designed to fit a cylindrical kelp stem. Shell ‘rocks’ on a flat surface. Outer surface brown, finely ribbed. Interior blue-white to brown.
About 90 mm.
Found almost exclusively on the kelp Ecklonia maxima. Adult form scars on the kelp stem and territorially thrust away intruding limpets. Instantly drops off if its host kelp is detached and floats to the surface. One of the first South African shells ever described, being named by Carl von Linné in 1758.
Two Oceans: A Guide to the Marine Life of Southern Africa (1994, 2016)
F*CK FISH 