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Temporal range: Devonian–recent
Haeckel Decapoda.jpg
"Decapoda" from Ernst Haeckel's Kunstformen der Natur, 1904
Scientific classification e
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Superorder: Eucarida
Order: Decapoda
Latreille, 1802

See text for superfamilies.

The Decapoda or decapods (literally "ten-footed") are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns, and shrimp. Most decapods are scavengers. The order is estimated to contain nearly 15,000 species in around 2,700 genera, with around 3,300 fossil species.[1] Nearly half of these species are crabs, with the shrimp (about 3,000 species) and Anomura including hermit crabs, porcelain crabs, squat lobsters (about 2500 species) making up the bulk of the remainder.[1] The earliest fossil decapod is the Devonian Palaeopalaemon.[2]


Decapods can have as many as 38 appendages,[3] arranged in one pair per body segment. As the name Decapoda (from the Greek δέκα, deca-, "ten", and πούς / ποδός, -pod, "foot") implies, ten of these appendages are considered legs. They are the pereiopods, found on the last five thoracic segments.[3] In many decapods, one pair of these "legs" has enlarged pincers, called chelae, with the legs being called chelipeds. In front of the pereiopods are three pairs of maxillipeds that function as feeding appendages. The head has five pairs of appendages, including mouthparts, antennae, and antennules. There are five more pairs of appendages on the abdomen. They are called pleopods. There is one final pair called uropods, which, with the telson, form the tail fan.[3]


Decapods originated in the Late Ordovician around 455 million years ago, with the Dendrobranchiata (prawns) being the first group to diverge. The remaining group, called Pleocyemata, then diverged between the swimming shrimp groupings and the crawling/walking group called Reptantia, consisting of lobsters and crabs. High species diversification can be traced to the Jurassic and Cretacious periods, which coincides with the rise and spread of modern coral reefs, a key habitat for the decapods.[4]

The cladogram below results from analysis by Wolfe et al., 2019.[4]


Dendrobranchiata (prawns) Litopenaeus setiferus.png


Stenopodidea (boxer shrimp) Spongicola venustus.png


Caridea (true shrimp) Macrobrachium sp.jpg

Reptantia (crawling/walking decapods)

Achelata (spiny lobsters, slipper lobsters) Panulirus argus.png


Astacidea (lobsters, crayfish) Lobster NSRW rotated2.jpg

Axiidea (mud shrimp, ghost shrimp, or burrowing shrimp)


Anomura (hermit crabs and others) Coenobita variabilis.jpg

Brachyura (crabs) Charybdis japonica.jpg


Classification within the order Decapoda depends on the structure of the gills and legs, and the way in which the larvae develop, giving rise to two suborders: Dendrobranchiata and Pleocyemata. The Dendrobranchiata consist of prawns, including many species colloquially referred to as "shrimp", such as the "white shrimp", Litopenaeus setiferus. The Pleocyemata include the remaining groups, including "true shrimp".[5] Those groups that usually walk rather than swim (Pleocyemata, excluding Stenopodidea and Caridea) form a clade called Reptantia.[6]

This classification to the level of superfamilies follows De Grave et al.[1]

Order Decapoda Latreille, 1802

See also[edit]


  2. ^ Robert P. D. Crean (November 14, 2004). "Order Decapoda: Fossil record and evolution". University of Bristol. Archived from the original on February 29, 2012. Retrieved January 2, 2010.
  3. ^ a b c "Decapoda characters and anatomy". University of Bristol: Decapoda characters. Archived from the original on 10 November 2013. Retrieved 11 December 2017.
  4. ^ a b Wolfe, Joanna M.; Breinholt, Jesse W.; Crandall, Keith A.; Lemmon, Alan R.; Lemmon, Emily Moriarty; Timm, Laura E.; Siddall, Mark E.; Bracken-Grissom, Heather D. (24 April 2019). "A phylogenomic framework, evolutionary timeline and genomic resources for comparative studies of decapod crustaceans". Proceedings of the Royal Society B. 286 (1901). doi:10.1098/rspb.2019.0079. PMID 31014217.
  5. ^ Elena Mente (2008). Reproductive Biology of Crustaceans: Case Studies of Decapod Crustaceans. Science Publishers. p. 16. ISBN 978-1-57808-529-3.
  6. ^ G. Scholtz; S. Richter (1995). "Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca)". Zoological Journal of the Linnean Society. 113 (3): 289–328. doi:10.1006/zjls.1995.0011.

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