It is found in shallow waters off the northwest coast of Europe and usually lives symbiotically with the sea anemone Adamsia palliata.

[2][1] Like other hermit crabs, P. prideaux has an asymmetric, unarmoured abdomen and protects this by concealing it within the empty shell of a gastropod of appropriate size and shape, and carrying it around by clasping onto an internal part of the columella of the sea snail shell.

[3] P. prideaux is found on sand, gravel and mud between the tide marks and in the shallow sublittoral.

Its base secretes a chitinous membrane that extends the gastropod shell, enlarging its capacity, and allowing the hermit crab to occupy it for a longer period.

Adult worms and the larval stages are frequently found in the apex of the gastropod shell.