The Stenopodidea or boxer shrimps are a small group of decapod

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

s. Often confused with Caridea shrimp or Dendrobranchiata prawns, they are neither, belonging to their own group.

Anatomy

They can be differentiated from the Dendrobranchiata prawns by their lack of branching

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

, and by the fact that they brood their eggs instead of directly releasing them into the water. They differ from the Caridea shrimp by their greatly enlarged third pair of legs.

Taxonomy

Stenopodidea belongs to the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

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 estim ...

, and is most closely related to the Caridea and

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 ...

infraorder 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 ...

s of

shrimp Shrimp are crustaceans (a form of shellfish) 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 ref ...

. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below shows Stenopodidea's relationships to other relatives within

, from analysis by Wolfe ''et al.'', 2019. There are 71 extant species currently recognized within Stenopodidea, divided into 12 genera. Three fossil species are also recognized, each belonging to a separate genus. The earliest fossil assigned to the Stenopodidea is '' Devonostenopus pennsylvaniensis'' from 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, wh ...

. Until ''D. pennsylvaniensis'' was discovered, the oldest known member of the group was '' Jilinicaris chinensis'' from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

. The cladogram below shows Stenopodidea's internal relationships:
Stenopodidea comprises the following families and

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

:
* Macromaxillocarididae Alvarez, Iliffe & Villalobos, 2006 **'' Macromaxillocaris'' Alvarez, Iliffe & Villalobos, 2006 * Spongicolidae Schram, 1986 **'' Engystenopus'' Alcock & Anderson, 1894 **'' Globospongicola'' Komai & Saito, 2006 **'' Jilinicaris'' † Schram, Shen, Vonk & Taylor, 2000 **'' Microprosthema'' Stimpson, 1860 **'' Paraspongicola'' De Saint Laurent & Cléva, 1981 **'' Spongicola'' De Haan, 1844 **'' Spongicoloides'' Hansen, 1908 **'' Spongiocaris'' Bruce & Baba, 1973 *

Stenopodidae Stenopodidae is a family of decapods in the order Decapoda. There are about 6 genera and more than 30 described species in Stenopodidae. Genera These six genera belong to the family Stenopodidae: * '' Juxtastenopus'' Goy, 2010 * '' Odontozona'' ...

Claus, 1872 **'' Devonostenopus'' † Jones ''et al.'', 2014 **''

Juxtastenopus ''Juxtastenopus spinulatus'' is a species of stenopodidean shrimp. It lives in the Red Sea, and across the Indian Ocean as far east as the Philippines. It is red or pink, up to long, with enlarged third pereiopods. Originally described in the ...

'' Goy, 2010 **'' Odontozona'' Holthuis, 1946 **'' Phoenice'' † Garassino, 2001 **'' Richardina'' A. Milne-Edwards, 1881 **''

Stenopus ''Stenopus'' is a genus of swimming decapod crustaceans containing eleven species, including ''Stenopus hispidus'', a common aquarium pet. ''Stenopus'' contains the following species: *'' Stenopus chrysexanthus'' Goy, 1992 *'' Stenopus cyanosce ...

'' Latreille, 1819

References

{{Taxonbar, from=Q932151 Arthropod infraorders Extant Late Devonian first appearances