Pagurus samuelis

(Stimpson, 1857)

blueband hermit crab

A small intertidal hermit crab to the eastern Pacific coast, distinguished by bright on the legs of . It is the most common hermit crab in California. The exhibits strong shell fidelity, preferentially occupying shells of the black turban ( funebralis). Behavioral studies demonstrate that shell acquisition takes priority over feeding when both resources are scarce, and that social isolation heightens aggressive and dominance in shell competition.

Pagurus samuelis by (c) Don Loarie, some rights reserved (CC BY). Used under a CC-BY license.

Pagurus samuelis by (c) Marilynne Box, some rights reserved (CC BY), uploaded by Marilynne Box. Used under a CC-BY license.

Blue Band Hermit Crab (Pagurus samuelis) (2311172655) by Jerry Kirkhart from Los Osos, Calif.. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Pagurus samuelis: /pəˈɡʊrəs sæmˈjuːɛlɪs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from similar hermit crabs by the combination of small size, bright on leg tips ( in ), red , and triangular . Most readily confused with Pagurus hirsutiusculus, which lacks the distinctive blue leg bands and has different preferences. Shell choice provides additional clue: P. samuelis strongly prefers funebralis shells, whereas may occupy different gastropod shells.

Images

Appearance

Small hermit crab reaching up to 40 mm total length and 19 mm width. Base coloration of is or green. are red. display distinctive bright near the tips of the legs; in smaller individuals these bands may appear . Legs and carapace covered in . at of carapace is triangular.

Habitat

Rocky intertidal zones along the eastern Pacific coast. Specifically associated with containing abundant funebralis shells. Found from the low intertidal to shallow subtidal zones.

Distribution

Eastern Pacific Ocean from Alaska to Punta Eugenia, Baja California, Mexico. Formerly misreported from Japan; those specimens now recognized as Pagurus filholi. Core abundance in California waters.

Seasonality

Breeding occurs May through July. Nocturnally active year-round in appropriate .

Diet

scavenger feeding primarily on , especially giant kelp (Macrocystis pyrifera), and carrion/detritus. Can survive on Pelvetia canaliculata in laboratory settings.

Host Associations

Tegula funebralis - shell providerStrongly preferred gastropod shell; crabs will occupy other shells when unavailable

Life Cycle

produced May–July, carried on female's inside shell. Males carry females on their backs during breeding season, sometimes for more than 24 hours. Developmental stages typical of decapod with planktonic larval phases, though specific details not well documented.

Behavior

scavenger. Exhibits pronounced behavioral plasticity in response to resource deprivation: shell-less individuals show heightened motivation to acquire shells, making fewer investigative contacts and faster decisions than non-deprived crabs. When simultaneously starved and shell-less, prioritizes shell acquisition over feeding. Social isolation increases high-ranking aggressive behaviors, dominance, and decisiveness in shell competition while reducing locomotory activity. Fear shows biphasic response to isolation (initial decrease, then increase above baseline).

Ecological Role

Scavenger and in rocky intertidal . for perch (Rhacochilus vacca), California sheephead (Semicossyphus pulcher), and spotted kelpfish (Gibbonsia elegans). Potential bioindicator for heavy metal based on differential metal accumulation patterns, though conclusive indicator status not established.

Human Relevance

Common subject of behavioral research due to accessibility and tractability in laboratory settings. Not of direct commercial importance. Provides service as scavenger in coastal environments.

Similar Taxa

Pagurus hirsutiusculusOverlapping range and similar size; distinguished by lack of leg , hairier appearance, and different microhabitat preferences
Pagurus filholiFormerly confused with P. samuelis; Japanese specimens previously misassigned to this