Portunidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s which contains the swimming crabs. Its members include well-known shoreline crabs such as the blue crab (''

Callinectes sapidus ''Callinectes sapidus'' (from the Ancient Greek language, Ancient Greek ,"beautiful" + , "swimmer", and Latin , "savory"), the blue crab, Atlantic blue crab, or, regionally, the Maryland blue crab, is a species of crab native to the waters of t ...

'') and velvet crab ('' Necora puber'').

Description

Portunid crabs are characterised by the flattening of the fifth pair of legs into broad paddles, which are used for

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

. This ability, together with their strong, sharp claws, allows many species to be fast and aggressive

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

Taxonomy

Swimming crabs reach their greatest species diversity in the Pacific and Indian Oceans. Portunidae consists of the following subfamilies and

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

: ;Achelouinae ;Caphyrinae ;Carupinae ;Coelocarcininae ;Lupocyclinae ;Necronectinae ;Podophthalminae ;Portuninae ;Thalamitinae ;''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

Notes

References

External links

* * Portunoidea Taxa named by Constantine Samuel Rafinesque Decapod families {{Portunoidea-stub