Decapoda

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

Dendrobranchiata
Pleocyemata
See text for superfamilies.

Contents

The Decapoda or decapods (literally "ten-footed") are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crabs, lobsters, crayfish, shrimp and prawns. 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]

Anatomy

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]

Evolution

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 Cretaceous 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]

Decapoda

Dendrobranchiata (prawns) Litopenaeus setiferus.png

Pleocyemata

Stenopodidea (boxer shrimp) Spongicola venustus.png

Procarididea

Caridea (true shrimp) Macrobrachium sp.jpg

Reptantia  (crawling/walking decapods)

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

Polychelida (benthic crustaceans)

Astacidea (lobsters, crayfish) Lobster NSRW rotated2.jpg

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

Gebiidea (mud lobsters and mud shrimp)

Anomura (hermit crabs and others) Coenobita variabilis.jpg

Brachyura (crabs) Charybdis japonica.jpg

Classification

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]

Whiteleg shrimp, Litopenaeus vannamei (Dendrobranchiata: Penaeoidea) Penaeus vannamei 01.jpg
Whiteleg shrimp, Litopenaeus vannamei (Dendrobranchiata: Penaeoidea)
Heterocarpus ensifer (Caridea: Pandaloidea) Heterocarpus ensifer.jpg
Heterocarpus ensifer (Caridea: Pandaloidea)
Austropotamobius pallipes (Astacidea: Astacoidea) Austropotamobius pallipes.jpg
Austropotamobius pallipes (Astacidea: Astacoidea)
Upogebia deltaura (Gebiidea: Upogebiidae) Upogebia deltaura.jpg
Upogebia deltaura (Gebiidea: Upogebiidae)
California spiny lobster, Panulirus interruptus (Achelata: Palinuridae) Lobster 300.jpg
California spiny lobster, Panulirus interruptus (Achelata: Palinuridae)
Polycheles sculptus (Polychelida: Polychelidae) Polycheles sculptus.jpg
Polycheles sculptus (Polychelida: Polychelidae)
Australian land hermit crab, Coenobita variabilis (Anomura: Paguroidea) CoenobitaVariabilis2.jpg
Australian land hermit crab, Coenobita variabilis (Anomura: Paguroidea)
Atlantic blue crab, Callinectes sapidus (Brachyura: Portunoidea) Blue crab on market in Piraeus - Callinectes sapidus Rathbun 20020819-317.jpg
Atlantic blue crab, Callinectes sapidus (Brachyura: Portunoidea)

Order DecapodaLatreille, 1802

See also

Related Research Articles

Dendrobranchiata Suborder of prawns

Dendrobranchiata is a suborder of decapods, commonly known as prawns. There are 540 extant species in seven families, and a fossil record extending back to the Devonian. They differ from related animals, such as Caridea and Stenopodidea, by the branching form of the gills and by the fact that they do not brood their eggs, but release them directly into the water. They may reach a length of over 330 millimetres (13 in) and a mass of 450 grams (1.0 lb), and are widely fished and farmed for human consumption.

Natantia Historic group of crustaceans

Natantia is an obsolete taxon of decapod crustaceans, comprising those families that move predominantly by swimming – the shrimp, prawns (Dendrobranchiata) and boxer shrimp. The remaining Decapoda were placed in the Reptantia, and consisted of crabs, lobsters and other large animals that move chiefly by walking along the bottom. The division between Natantia and Reptantia was replaced in 1963, when Martin Burkenroad erected the suborder Pleocyemata for those animals that brood their eggs on the pleopods, leaving Dendrobranchiata for the prawns. Under this system, Natantia is a paraphyletic group. Burkenroad's primary division of Decapoda into Dendrobranchiata and Pleocyemata has since been corroborated by molecular analyses.

Malacostraca Largest class of crustaceans

Malacostraca is the largest of the six classes of crustaceans, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, amphipods, mantis shrimp, tongue-eating lice and many other less familiar animals. They are abundant in all marine environments and have colonised freshwater and terrestrial habitats. They are segmented animals, united by a common body plan comprising 20 body segments, and divided into a head, thorax, and abdomen.

Reptantia Suborder of crustaceans

Reptantia is a clade of decapod crustaceans named in 1880 which includes lobsters, crabs and many other well-known crustaceans.

Pleocyemata Suborder of crustaceans

Pleocyemata is a suborder of decapod crustaceans, erected by Martin Burkenroad in 1963. Burkenroad's classification replaced the earlier sub-orders of Natantia and Reptantia with the monophyletic groups Dendrobranchiata (prawns) and Pleocyemata. Pleocyemata contains all the members of the Reptantia, as well as the Stenopodidea, and Caridea, which contains the true shrimp.

Achelata Infraorder of crustaceans

The Achelata is an infra-order of the decapod crustaceans, holding the spiny lobsters, slipper lobsters and their fossil relatives.

Anomura Infraorder of crustaceans

Anomura is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans include the word crab, all true crabs are in the sister group to the Anomura, the Brachyura.

Stenopodidea Infraorder of crustaceans

The Stenopodidea or boxer shrimps are a small group of decapod crustaceans. Often confused with Caridea shrimp or Dendrobranchiata prawns, they are neither, belonging to their own group.

Astacidea Infraorder of crustaceans

Astacidea is an infraorder of decapod crustaceans including lobsters, crayfish, and their close relatives.

Thalassinidea Infraorder of crustaceans

Thalassinidea is a former infraorder of decapod crustaceans that live in burrows in muddy bottoms of the world's oceans. In Australian English, the littoral thalassinidean Trypaea australiensis is referred to as the yabby, frequently used as bait for estuarine fishing; elsewhere, however, they are poorly known, and as such have few vernacular names, "mud lobster" and "ghost shrimp" counting among them. The burrows made by thalassinideans are frequently preserved, and the fossil record of thalassinideans reaches back to the late Jurassic.

Eucarida Superorder of crustaceans

Eucarida is a superorder of the Malacostraca, a class of the crustacean subphylum, comprising the decapods, krill, Amphionides and Angustidontida. They are characterised by having the carapace fused to all thoracic segments, and by the possession of stalked eyes.

Portunidae Family of crabs

Portunidae is a family of crabs which contains the swimming crabs.

Majidae Family of crabs

Majidae is a family of crabs, comprising around 200 marine species inside 52 genera, with a carapace that is longer than it is broad, and which forms a point at the front. The legs can be very long in some species, leading to the name "spider crab". The exoskeleton is covered with bristles to which the crab attaches algae and other items to act as camouflage.

Majoidea Superfamily of crabs

The Majoidea are a superfamily of crabs which includes the various spider crabs.

Polychelida Infraorder of crustaceans

Polychelida is an infraorder of decapod crustaceans. Fossil representatives are known dating from as far back as the Upper Triassic. A total of 38 extant species, all in the family Polychelidae, and 55 fossil species have been described.

Pilumnoidea Superfamily of crabs

Pilumnoidea is a superfamily of crabs, whose members were previously included in the Xanthoidea. The three families are unified by the free articulation of all the segments of the male crab's abdomen and by the form of the gonopods. The earliest fossils assigned to this group are of Eocene age.

Palaemonoidea Superfamily of shrimp

Palaemonoidea is a large superfamily of shrimp, containing nearly 1,000 species. The position of the family Typhlocarididae is unclear, although the monophyly of a group containing the remaining seven families is well supported.

Crustacean larva Crustacean larval and immature stages between hatching and adult form

Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.

Spongicolidae Family of crustaceans

Spongicolidae is a family of glass sponge shrimps in the order Decapoda. There are about 8 genera and more than 40 described species in Spongicolidae.

Shrimp Decapod crustaceans

Shrimp are crustaceans with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are referred to as "shrimp".

References

  1. 1 2 3 Sammy De Grave; N. Dean Pentcheff; Shane T. Ahyong; et al. (2009). "A classification of living and fossil genera of decapod crustaceans" (PDF). Raffles Bulletin of Zoology . Suppl. 21: 1–109. Archived from the original (PDF) on 2011-06-06.
  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. 1 2 3 "Decapoda characters and anatomy". University of Bristol: Decapoda characters. Archived from the original on 10 November 2013. Retrieved 11 December 2017.
  4. 1 2 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 . PMC   6501934 . 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.