The exterior surface of holdfast dwellers is less smooth than on frond and stipe dwellers and, on this one, is partly coated with epizoic animals . As usual, the juvenile growth is mainly free of epizoa.
This GS5 shell has acquired a thickening interior layer with a distinct pedal-retractor-muscle scar (1) and mantle-attachment scar (2) .
Concise
Part 1, SHELL FORMS: 02 Patella pellucida. Growth Stage 2 (GS2). July 2012. Littoral. North Yorkshire, England. © P. Lightfoot.
Part 2, BODY & ANATOMY: 03 Patella pellucida. Growth Stage 3 (GS3). 2009. Sublittoral, Farne Islands, Northumberland, England. © P.Lightfoot.
Part, 3 HABITS & ECOLOGY: 04 Patella pellucida. Length 4.6mm. Growth Stage 3 (GS3). September 2016. Yorkshire, England. © P.Lightfoot.