Anemone-symbiosis
Guides
Diogenidae
Left-handed Hermit Crabs
Diogenidae is the second-largest family of marine hermit crabs, comprising 429 extant and 47 extinct species. Members are distinguished by an enlarged left chela (claw), earning them the common name 'left-handed hermit crabs'—the reverse of the typical pattern in other hermit crab families. The family includes both conventional shell-dwelling species and the unusual 'blanket-hermit crabs' of the genus Paguropsis, which live in symbiosis with sea anemones rather than occupying gastropod shells.
Paguroidea
hermit crabs
Paguroidea is a superfamily of decapod crustaceans comprising approximately 1100 species commonly known as hermit crabs. Members are characterized by a soft, asymmetrical abdomen adapted to occupy empty gastropod shells or, in specialized lineages, symbiotic relationships with sea anemones that form protective 'blankets' or 'carcinoecia'. The superfamily exhibits remarkable diversity in shell-use strategies, from traditional gastropod shells to bivalve shells and anemone-derived structures. Distributed across marine environments from intertidal zones to deep-sea habitats, with some lineages having colonized terrestrial ecosystems.