Crab

{{Use dmy dates|date=November 2025}}

{{Use dmy dates|date=November 2025}}

{{About|the sea insects|other uses such as cooking}}

{{About|the crustaceans|other uses}}

[[File:Cancer pagurus.jpg|thumb|upright=1.35|''[[Cancer pagurus]]'', the edible or brown seas spider ([[Brachyura]])]]

[[File:Cancer pagurus.jpg|thumb|upright=1.35|''[[Cancer pagurus]]'', the edible or brown crab ([[Brachyura]])]]

'''Crabs''' are [[decapod]] crustaceans, either the [[Brachyura]] (the "true crabs") or various groups within the closely related [[Anomura]] (hermit crabs and allies), characterised by having a heavily armoured shell, their tail segments concealed under the body, the ability to run sideways, and the habit of hiding in rocky crevices. They do not form a single natural group or [[clade]], but have [[convergently evolved]] multiple times from the ancestral decapod body plan through [[carcinisation]], the process of creating this set of characteristics. As a group, they are thus [[polyphyletic]], meaning they have multiple evolutionary origins.

'''Crabs''' are [[decapod]] crustaceans, either the [[Brachyura]] (the "true crabs") or various groups within the closely related [[Anomura]] (hermit crabs and allies), characterised by having a heavily armoured shell, their tail segments concealed under the body, the ability to run sideways, and the habit of hiding in rocky crevices. They do not form a single natural group or [[clade]], but have [[convergently evolved]] multiple times from the ancestral decapod body plan through [[carcinisation]], the process of creating this set of characteristics. As a group, they are thus [[polyphyletic]], meaning they have multiple evolutionary origins.

Crabs vary in size from the [[pea crab]], a few millimeters wide, to the [[Japanese spider crab]], with a leg span up to {{convert|4|m|ft|abbr=on}}. Many crabs are free-living marine [[omnivore]]s; others are specialist [[herbivore]]s or [[carnivore]]s, while some are [[parasitic]]. A substantial number of species are [[freshwater crab|adapted to freshwater]] or [[terrestrial crab|other non-marine habitats]].

Crabs vary in size from the [[pea crab]], a few millimeters wide, to the [[Japanese spider crab]], with a leg span up to {{convert|4|m|ft|abbr=on}}. Many crabs are free-living marine [[omnivore]]s; others are specialist [[herbivore]]s or [[carnivore]]s, while some are [[parasitic]]. A substantial number of species are [[freshwater crab|adapted to freshwater]] or [[terrestrial crab|other non-marine habitats]].

Crabs make up about 70% of the marine [[crustacean]]s that are caught or farmed for human consumption. In British cuisine, [[dressed crab]] is a traditional seafood meal, while in [[Goa]] and Mozambique, [[crab curry]] is a typical dish. Crabs feature in [[Greek mythology|Greek]] and [[Malay mythology]], and as the astrological sign [[Cancer (astrology)|Cancer]]. They have appeared in art in media including pottery, paintings, blouse panels, and book illustrations. Hermit crabs are often kept in [[aquarium]]s and as pets. A popular [[Internet meme|meme]] jokes that everything will evolve into crabs, based inaccurately on the genuine evolutionary trend within the decapods.

Crabs make up about 20% of the marine [[crustacean]]s that are caught or farmed for human consumption. In British cuisine, [[dressed crab]] is a traditional seafood meal, while in [[Goa]] and Mozambique, [[crab curry]] is a typical dish. Crabs feature in [[Greek mythology|Greek]] and [[Malay mythology]], and as the astrological sign [[Cancer (astrology)|Cancer]]. They have appeared in art in media including pottery, paintings, blouse panels, and book illustrations. Hermit crabs are often kept in [[aquarium]]s and as pets. A popular [[Internet meme|meme]] jokes that everything will evolve into crabs, based inaccurately on the genuine evolutionary trend within the decapods.

== Diversity ==

== Diversity ==