Streamlined juveniles on Laminaria hyperborea frond, orientated with prow-like anteriors probably facing from whence wave or current impact comes. The width of the blue lines remains fairly constant at 0.1mm to 0.2mm at all growth stages. These juveniles also have a variable number of red-brown rays interspersed between the blue ones, but this is a more frequent feature on adults in holdfasts; Graham & Fretter (1947) only found red-brown rays on a juvenile once in a study of 684 shells. Radula marks on the frond suggest that the limpets swing their heads in an arc as they feed.
A dark chestnut band on the distal face of the horseshoe-shaped pedal-retractor muscle can be seen through the translucent shells of four of these juveniles.