Pleocyemata is a

suborder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

of decapod

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, erected by

Martin Burkenroad Martin David Burkenroad (March 20, 1910 – January 12, 1986) was an American marine biologist. He specialized in decapod crustaceans and fisheries science. Biography Burkenroad was born in New Orleans in 1910 as the only child of coffee import ...

in 1963. Burkenroad's classification replaced the earlier sub-orders of

Natantia Natantia (Boas, 1880) is an obsolete taxon of decapod crustaceans, comprising those families that move predominantly by swimming – the shrimp (comprising Caridea and Procarididea), prawns (Dendrobranchiata) and boxer shrimp. The remaining Decap ...

and

Reptantia Reptantia is a clade of decapod crustaceans named in 1880 which includes lobsters, crabs and many other well-known crustaceans. Classification In older classifications, Reptantia was one of the two sub-orders of Decapoda alongside Natantia, wi ...

with the monophyletic groups

Dendrobranchiata Dendrobranchiata is a suborder of Decapoda, 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 ...

(prawns) and Pleocyemata. Pleocyemata contains all the members of the Reptantia (including crabs, lobsters, crayfish, and others), as well as the

Stenopodidea 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. Anatomy They can be differentiated from the Dendrobranc ...

(which contains the so-called "boxer shrimp" or "barber-pole shrimp"), and

Caridea The Caridea, commonly known as caridean shrimp or true shrimp, are an infraorder of shrimp within the order Decapoda. This infraorder contains all species of true shrimp. They are found widely around the world in both fresh and salt water. Many ...

, which contains the true shrimp.

Anatomy

All members of the Pleocyemata are united by a number of features, the most important of which is that the fertilised

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s are incubated by the female, and remain stuck to the

pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

s (swimming legs) until the

zoea 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 are ready to hatch. It is this characteristic that gives the group its name. Pleocyemata also possess a

lamellar A ''lamella'' (plural ''lamellae'') is a small plate or flake, from the Latin, and may also be used to refer to collections of fine sheets of material held adjacent to one another, in a gill-shaped structure, often with fluid in between though s ...

gill structure as opposed to the branches found in the

Systematics

The cladogram below shows Pleocyemata as the

sister clade In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

within the larger order

Decapoda 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 esti ...

, from analysis by Wolfe ''et al.'', 2019. Pleocyemata comprises the following infraorders: *

(stenopodidean shrimp) *

(caridean shrimp) *

Procarididea Procarididea is an infraorder of decapods, comprising only eleven species. Six of these are in the genera ''Procaris'' and '' Vetericaris'', which together make up the family Procarididae. The remaining five species are only known from fossils an ...

Achelata The Achelata is an infra-order of the decapod crustaceans, holding the spiny lobsters, slipper lobsters and their fossil relatives. Description The name "Achelata" derives from the fact that all the members of this group lack the chelae (claw ...

(spiny, slipper, and furry lobsters) *

Polychelida 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. Histor ...

(benthic crustaceans) *

Glypheidea Glypheidea is an infraorder of lobster-like decapod crustaceans, comprising a number of fossil forms and the two extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving lit ...

(glypheoid lobsters) *

Astacidea Astacidea is an infraorder of decapod crustaceans including lobsters (though not "lobsters" such as the spiny lobster etc.), crayfish, and their close relatives. Description The Astacidea are distinguished from most other decapods by the presen ...

(true lobsters, reef lobsters, and crayfish) *

Axiidea Axiidea is an infraorder of decapod crustaceans. They are colloquially known as mud shrimp, ghost shrimp, or burrowing shrimp; however, these decapods are only distantly related to true shrimp. Axiidea and Gebiidea are divergent infraoders of ...

(mud lobsters and ghost shrimp) *

Gebiidea Gebiidea is an infraorder of Decapoda, decapod crustaceans. Gebiidea and Axiidea are divergent infraoders of the former infraorder Thalassinidea. These infraorders have converged Ecology, ecologically and Morphology (biology), morphologically as ...

(mud lobsters and mud shrimp) *

Anomura Anomura (sometimes Anomala) is a group of Decapoda, 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 (the ...

(squat lobsters, hermit crabs, and relatives) * Brachyura (true crabs) The earliest

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

representative is the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

Palaeopalaemon ''Palaeopalaemon'' is an extinct genus of the oldest lobster-like aquatic decapod crustaceans, containing the species ''Palaeopalaemon newberryi''. References {{Taxonbar, from1=Q98077933, from2=Q107155530 Decapods Prehistoric crustacean ge ...

''.

References

External links

* {{Taxonbar, from=Q147873 Decapods Extant Devonian first appearances Arthropod suborders