It prefers to live in the shell of the black turban snail, and is a nocturnal scavenger of algae and carrion.

[2] The base colour of the exoskeleton is brown or green,[2] but the antennae are red, and adults have bright blue bands near the tips of their legs.

It was formerly thought to also occur in Japan, but the Japanese specimens which were formerly assigned to this species are now recognised as Pagurus filholi.

[4][5] Pagurus samuelis prefers to use the discarded shell of the black turban snail, Tegula funebralis.

[2] Predators of P. samuelis include fishes such as the pile perch (Rhacochilus vacca), California sheephead (Semicossyphus pulcher) and the spotted kelpfish, Gibbonsia elegans.