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.

While Dendrobranchiata and Caridea belong to different suborders of Decapoda, they are very similar in appearance, and in many contexts such as commercial farming and fisheries, they are both often referred to as "shrimp" and "prawn" interchangeably.

In the United Kingdom, Australia and some other Commonwealth, the word "prawn" is used almost exclusively, while the opposite is the case in North America.

[15] More than 17 muscles operate each of the pleopods, and a further 16 power the tail fan in the rapid backward movement of the caridoid escape reaction.

[17] The nervous system of prawns comprises a dorsal brain, and a ventral nerve cord, connected by two commissures around the oesophagus.

[20] The foregut begins at the mouth, passes through the oesophagus, and opens into a sac that contains the grinding apparatus of the gastric mill.

[25] In closed-thelycum species, mating takes place shortly after moulting, when the exoskeleton is still soft, and usually occurs in the night.

[31] Dendrobranchiata were traditionally grouped together with Caridea as "Natantia" (the swimming decapoda), as opposed to the Reptantia (the walking decapods).

In 1888, Charles Spence Bate recognised the differences in gill morphology, and separated Natantia into Dendrobranchiata, Phyllobranchiata and Trichobranchiata.

[32] Recent analyses using cladistics and molecular phylogenetics recognise Dendrobranchiata as the sister group to all other Decapoda, collectively called Pleocyemata.

Before 2010, the earliest known fossil prawns come from rocks in Madagascar of Permo-Triassic age, 250 million years ago.

[35][36] In 2010, however, the discovery of Aciculopoda from Famennian–stage rocks in Oklahoma extended the group's fossil record back to 360 million years ago.

[36] Living prawns are divided among seven families, five in the superfamily Penaeoidea, and two in the Sergestoidea,[2] although molecular evidence disagrees with some aspects of the current classifications.

[1] The cladogram below shows Dendrobranchiata's internal relationships of extant families (excluding Solenoceridae):[34] Luciferidae Sergestidae Sicyoniidae Penaeidae Benthesicymidae Aristeidae

[31] Prawns are "opportunistic omnivores",[47] and their diet can include a range of food items from fine particles to large organisms.

These may include fish, chaetognaths, krill, copepods, radiolarians, phytoplankton, nematocysts, ostracods and detritus.

[48] The larvae are prey to comb jellies, jellyfish, chaetognaths, fish and other crustaceans (such as mantis shrimp and crabs), and only a tiny proportion survive.

[51] Species from the family Aristeidae are important to deep-water fisheries, particularly in the Mediterranean Sea, where Aristaeomorpha foliacea is caught by trawlers.