Editing Branchiopoda

{{Short description|Class of crustaceans}}
{{Redirect-distinguish|Branchiopod|Brachiopod}}
{{Automatic taxobox
| name = Branchiopoda
| image = Branchiopoda collage 2x2.png
| image_caption = Clockwise from top left: ''[[Artemia]]'' ([[Anostraca]]), ''[[Triops]]'' ([[Notostraca]]), ''[[Daphnia]]'' ([[Cladocera]]) & ''[[Cyzicus (genus)|Cyzicus]]'' ([[Spinicaudata]])
| fossil_range = {{Fossil range|Upper Cambrian|Recent|earliest=Middle Cambrian}}
| taxon = Branchiopoda
| authority = [[Pierre André Latreille|Latreille]], 1817
| subdivision_ranks = Subclasses
| subdivision = * [[Sarsostraca]] <small>Tasch, 1969</small>
* '''Phyllopoda''' <small>Preuss, 1951</small>
}}

'''Branchiopoda''', from [[Ancient Greek]] βράγχια (''bránkhia''), meaning "gill", and πούς (''poús''), meaning "foot", is a [[class (biology)|class]] of [[crustacean]]s. It comprises [[Anostraca|fairy shrimp]], [[clam shrimp]], [[Diplostraca]] (or Cladocera), [[Notostraca]], the Devonian ''[[Lepidocaris]]'' and possibly the Cambrian ''[[Rehbachiella]]''. They are mostly small, freshwater animals that feed on plankton and detritus.

==Description==
Members of the Branchiopoda are unified by the presence of [[gill]]s on many of the animals' [[appendage]]s, including some of the [[arthropod mouthparts|mouthparts]]. This is also responsible for the name of the group<ref>{{cite book |title=The animal kingdom: arranged after its organization, forming a natural history of animals, and an introduction to comparative anatomy |author=Georges Cuvier |translator=William Benjamin Carpenter |publisher=W. S. Orr and co. |year=1851 |chapter-url=https://books.google.com/books?id=fPvRAAAAMAAJ |chapter=Crustacean Entomostraca (Müller) |pages=434–448|author-link=Georges Cuvier }}</ref> (from the {{langx|grc|βράγχια}}, gills, akin to {{lang|grc|βρόγχος}}, [[windpipe]]; {{langx|el|πούς}}, foot).<ref>{{cite book |title=Webster's New World College Dictionary |year=2010 |publisher=[[Wiley Publishing]] |location=Cleveland, Ohio |url=http://www.yourdictionary.com/branchio-prefix |access-date=April 20, 2010 |archive-date=October 23, 2016 |archive-url=https://web.archive.org/web/20161023223806/http://www.yourdictionary.com/branchio-prefix |url-status=dead }}</ref> They generally possess [[compound eye]]s and a [[carapace]], which may be a shell of two valves enclosing the trunk (as in most Cladocera), broad and shallow (as in the Notostraca), or entirely absent (as in the Anostraca).<ref name="Hyman">{{cite book |title=The Invertebrata |pages=368–375 |chapter=Subclass 1. Branchiopoda |publisher=[[Cambridge University Press]] |year=1961 |edition=4th |author=Libbie Hyman |chapter-url=https://books.google.com/books?id=7FM8AAAAIAAJ&pg=PA373|author-link=Libbie Hyman }}</ref> In the groups where the carapace prevents the use of the trunk limbs for swimming (Cladocera and clam shrimp), the [[antenna (biology)|antennae]] are used for locomotion, as they are in the [[nauplius (larva)|nauplius]].<ref name="Hyman"/> Male fairy shrimp have an enlarged pair of antennae with which they grasp the female during mating, while the [[bottom feeder|bottom-feeding]] Notostraca, the antennae are reduced to [[Vestigiality|vestiges]].<ref name="Hyman"/> The trunk limbs are beaten in a [[metachronal rhythm]], causing a flow of water along the midline of the animal, from which it derives [[oxygen]], [[food]] and, in the case of the Anostraca and Notostraca, movement.<ref name="Hyman"/>

==Ecology==
Branchiopods are found in continental [[freshwater|fresh water]], including [[vernal pool|temporary pools]] and in [[hypersaline lake]]s, and some in [[brackish water]]. Only two groups of [[Diplostraca|water fleas]] include marine species: Family [[Podonidae]] in the order [[Diplostraca]], and family [[Sididae]] in the order [[Diplostraca]].<ref>{{cite book |author=Sol Felty Light |title=Intertidal invertebrates of the central California coast |publisher=[[University of California Press]] |year=1970 |isbn=978-0-520-00750-5 |chapter=Phylum Arthropoda |pages=112–210}}</ref><ref>[https://books.google.com/books?id=qG9WEAAAQBAJ&dq=marine+cladoceran+Podonidae+Sididae&pg=PA114 Marine Biology: A Functional Approach to the Oceans and their Organisms]</ref><ref>[https://books.google.com/books?id=KEXwCAAAQBAJ&dq=Salinity+tolerance+and+morphology+Cladocera+Aral+sea&pg=PA291 Biology of Cladocera: Proceedings of the Second International Symposium on Cladocera]</ref>
Most branchiopodans eat floating [[detritus]] or [[plankton]], which they take using the [[seta]]e on their appendages.<ref name="Hyman"/> But [[notostracans]] are omnivorous and very opportunistic feeders and will eat algae and bacteria in addition to animals as both predators and scavengers.<ref>{{Cite journal |last1=Brostoff |first1=Wn |last2=Holmquist |first2=Jg |last3=Schmidt-Gengenbach |first3=J |last4=Zimba |first4=Pv |date=2010 |title=Fairy, tadpole, and clam shrimps (Branchiopoda) in seasonally inundated clay pans in the western Mojave Desert and effect on primary producers |journal=Saline Systems |language=en |volume=6 |issue=1 |pages=11 |doi=10.1186/1746-1448-6-11 |doi-access=free |issn=1746-1448 |pmc=3019125 |pmid=21143855}}</ref>

==Taxonomy==
In early taxonomic treatments, the current members of the Branchiopoda were all placed in a single genus, ''Monoculus''.<ref name="Jørgensen"/> The taxon Branchiopoda was erected by [[Pierre André Latreille]] in 1817, initially at the [[taxonomic rank|rank]] of [[Order (biology)|order]].<ref name=Cuvier1831/>

The current upper-level classification of Branchiopoda, according to the World Register of Marine Species (2021), is as follows:<ref name=worms/>

'''Class Branchiopoda <small>Latreille, 1817</small>'''
: '''Subclass [[Sarsostraca]] <small>Tasch, 1969</small>'''
::Order [[Anostraca]] <small>Sars, 1867</small>
:::Suborder [[Anostracina]] <small>Weekers et al., 2002</small>
:::Suborder [[Artemiina]] <small>Weekers et al., 2002</small>
: '''Subclass Phyllopoda <small>Preuss, 1951</small>'''
:: Superorder [[Diplostraca]] <small>Gerstaecker, 1866</small>
::: Order [[Anomopoda]] <small>G.O. Sars, 1865</small>
::: Order [[Ctenopoda]] <small>G.O. Sars, 1865</small>
::: Order [[Cyclestherida]] <small>Sars G.O., 1899</small>
::: Order [[Haplopoda]] <small>G.O. Sars, 1865</small>
::: Order [[Laevicaudata]] <small>Linder, 1945</small>
::: Order [[Onychopoda]] <small>G.O. Sars, 1865</small>
::: Order [[Spinicaudata]] <small>Linder, 1945</small>
:: Order [[Notostraca]] <small>G. O. Sars, 1867</small>
::Genus †''[[Rehbachiella]]''? <small>Müller, 1983</small>
In addition, the extinct genus ''[[Lepidocaris]]'' is generally placed in Branchiopoda.

===Anostraca===
[[File:Artemia salina 3.jpg|thumb|right|''[[Artemia salina]]'' ([[Anostraca]]: [[Artemiidae]])]]
{{Main|Anostraca}}
The fairy shrimp of the order [[Anostraca]] are usually {{convert|6|-|25|mm|abbr=on}} long (exceptionally up to {{convert|170|mm|abbr=on|disp=or}}).<ref name="Belk"/> Most species have 20 body segments, bearing 11 pairs of leaf-like ''phyllopodia'' (swimming legs), and the body lacks a [[carapace]].<ref name="Khanna">{{cite book |author=D. R. Khanna |year=2004 |title=Biology of Arthropoda |publisher=[[Discovery Publishing House]] |isbn=978-81-7141-897-8 |chapter=Segmentation in arthropods |pages=316–394 |chapter-url=https://books.google.com/books?id=Hd4OEDo4gbwC&pg=PA347}}</ref> They live in [[vernal pool]]s and [[hypersaline lake]]s across the world, including pools in [[desert]]s, in ice-covered mountain lakes and in [[Antarctica]]. They swim "upside-down" and [[filter feeder|feed by filtering]] organic particles from the water or by scraping [[algae]] from surfaces.<ref name="Belk"/> They are an important food for many birds and fish, and are cultured and harvested for use as fish food.<ref name="Jørgensen"/> There are 300 species spread across 8 [[family (biology)|families]].<ref name="Diversity">{{cite journal |author=Luc Brendonck |author2=D. Christopher Rogers |author3=Jorgen Olesen |author4=Stephen Weeks |author5=Walter R. Hoch |year=2008 |title=Global diversity of large branchiopods (Crustacea: Branchiopoda) in freshwater |journal=[[Hydrobiologia]] |volume=595 |issue=1 |pages=167–176 |doi=10.1007/s10750-007-9119-9|s2cid=46608816 }}</ref>

===Lipostraca===
{{Main|Lepidocaris}}
Lipostraca contains a single extinct Early Devonian species, ''[[Lepidocaris|Lepidocaris rhyniensis]]'',<ref>{{cite book |author1=Paul Selden  |author2=John R. Nudds  |name-list-style=amp |year=2004 |title=Evolution of Fossil Ecosystems |edition=2nd |publisher=[[Manson Publishing]] |isbn=978-1-84076-041-5  |chapter=The Rhynie Chert |pages=47–58 |chapter-url=https://books.google.com/books?id=caNHa2Ad604C&pg=PA55}}</ref> which is the most abundant animal in the [[Rhynie chert]] deposits.<ref>{{cite web |url=http://www.ucmp.berkeley.edu/arthropoda/crustacea/branchiopoda.html |title=Introduction to Branchiopoda |publisher=[[University of California, Berkeley]] |access-date=August 5, 2011}}</ref> It resembles modern Anostraca, to which it is probably closely related, although its relationships to other orders remain unclear.<ref>{{cite journal |author=Frederick R. Schram |author2=Stefan Koenemann |year=2001 |title=Developmental genetics and arthropod evolution: part I, on legs |journal=[[Evolution & Development]] |volume= 3 |issue=5 |pages=343–354 |doi=10.1046/j.1525-142X.2001.01038.x |pmid=11710766|s2cid=25997101 |author-link=Frederick R. Schram }}</ref> The body is {{convert|3|mm|abbr=on}} long, with 23 body segments and 19 pairs of [[appendage]]s, but no [[carapace]].<ref>{{cite journal |author=D. J. Scourfield |year=1926 |title=On a new type of crustacean from the old Red Sandstone (Rhynie chert Bed, Aberdeenshire) – ''Lepidocaris rhyniensis'', gen. et sp. nov. |journal=[[Philosophical Transactions of the Royal Society B: Biological Sciences]] |volume=214 |issue=411–420 |pages=153–187 |jstor=92140 |doi=10.1098/rstb.1926.0005|bibcode=1926RSPTB.214..153S |doi-access=free }}</ref> It occurred chiefly among [[charophyte]]s, probably in alkaline [[vernal pool|temporary pools]].<ref name="abdn">{{cite web |url=http://www.abdn.ac.uk/rhynie/lepid.htm |title=''Lepidocaris'' |publisher=[[University of Aberdeen]] |work=The Rhynie Chert Crustaceans |access-date=August 5, 2011}}</ref>

===Notostraca===
{{Main|Notostraca}}
The order [[Notostraca]] comprises the single family Triopsidae, containing the tadpole shrimp or shield shrimp.<ref name="Lowry">{{cite web |url=http://crustacea.net/crustace/www/notostra.htm |author=J. K. Lowry |work=Crustacea, the Higher Taxa: Description, Identification, and Information Retrieval |date=October 2, 1999 |title=Notostraca (Branchiopoda) |access-date=February 7, 2011 |archive-url=https://web.archive.org/web/20110723062941/http://crustacea.net/crustace/www/notostra.htm |archive-date=July 23, 2011 |url-status=dead }}</ref> The two genera, ''[[Triops]]'' and ''[[Lepidurus]]'', are considered [[living fossil]]s, having not changed significantly in outward form since the [[Triassic]].<ref name="Diversity"/> They have a broad, flat carapace, which conceals the head and bears a single pair of compound eyes.<ref name="Belk"/> The abdomen is long, appears to be segmented and bears numerous pairs of flattened legs.<ref name="Belk"/> The [[telson]] is flanked by a pair of long, thin caudal rami.<ref name="Hyman"/> [[Phenotypic plasticity]] within taxa makes species-level identification difficult, and is further compounded by variation in the mode of reproduction.<ref name="Diversity"/><ref>{{Cite journal|last=Lakka|first=Hanna-Kaisa|date=2015|title=Description of the male Lepidurus arcticus (Branchiopoda: Notostraca) and the potential role of cannibalism in defining male form and population sex ratio|journal=Journal of Crustacean Biology|volume=35|issue=3|pages=319–329|doi=10.1163/1937240X-00002324|s2cid=83523163 |doi-access=free}}</ref> The evidence of phenotypic plasticity of Arctic tadpole shrimp (''[[Lepidurus arcticus]]'', Notostraca) has been observed in Svalbard.<ref name=":0">{{Cite book|last=Lakka|first=Hanna-Kaisa|url=http://urn.fi/URN:NBN:fi-fe20180115161|title=The ecology of a freshwater crustacean : Lepidurus arcticus (Brachiopoda; Notostraca) in a High Arctic region (master's thesis).|publisher=University of Helsinki|year=2013|pages=151|language=en}}</ref>  Notostracans are the largest branchiopodans and are [[omnivore]]s living on the bottom of [[temporary pool]]s, ponds<ref name=":0">{{Cite book|last=Lakka|first=Hanna-Kaisa|url=http://urn.fi/URN:NBN:fi-fe20180115161|title=The ecology of a freshwater crustacean : Lepidurus arcticus (Brachiopoda; Notostraca) in a High Arctic region (master's thesis).|publisher=University of Helsinki|year=2013|pages=151|language=en}}</ref> and shallow lakes.<ref name="Belk"/>

===Laevicaudata, Spinicaudata and Cyclestherida (once Conchostraca)===
{{Main|Clam shrimp}}
Clam shrimp are bivalved animals which have lived since at least the [[Devonian]]. The three groups are not believed to form a [[clade]]. They have 10–32 trunk segments, decreasing in size from front to back, and each bears a pair of [[arthropod leg|legs]] which also carry [[gill]]s. A strong muscle can close the two halves of the shell together.

===Anomopoda, Ctenopoda, Onychopoda, and Haplopoda (once Cladocera)===
[[File:Daphnia pulex.png|thumb|right|''[[Daphnia pulex]]'' ([[Cladocera]]: [[Daphniidae]])]]
These four [[order (biology)|order]]s make up a group of small [[crustacean]]s commonly called water fleas. Around 620 species have been recognised so far, with many more [[undescribed species|undescribed]].<ref name="Forró">{{cite journal |author=L. Forró |author2=N. M. Korovchinsky |author3=A. A. Kotov |author4=A. Petrusek |year=2008 |title=Global diversity of cladocerans (Cladocera; Crustacea) in freshwater |journal=[[Hydrobiologia]] |volume=595 |issue=1 |pages=177–184 |doi=10.1007/s10750-007-9013-5 |s2cid=45363782 |url=http://decapoda.nhm.org/pdfs/27704/27704.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://decapoda.nhm.org/pdfs/27704/27704.pdf |archive-date=2022-10-09 |url-status=live }}</ref> They are ubiquitous in inland aquatic habitats, but rare in the oceans.<ref name="Belk">{{cite book |editor1=Sol Felty Light |editor2=James T. Carlton |year=2007 |title=The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon |edition=4th |publisher=[[University of California Press]] |isbn=978-0-520-23939-5|chapter=Branchiopoda |author=Denton Belk |pages=414–417 |chapter-url=https://books.google.com/books?id=64jgZ1CfmB8C&pg=PA416}}</ref> Most are {{convert|0.2|-|6.0|mm|2|abbr=on}} long, with a down-turned head, and a carapace covering the apparently unsegmented thorax and abdomen.<ref name="Pennak_Cladocera">{{cite book |editor=Douglas Grant Smith |chapter=Cladoceran Branchiopoda (water fleas) |pages=453 488 |author1=Douglas Grant Smith  |author2=Kirstern Work  |name-list-style=amp |year=2001 |title=Pennak's Freshwater Invertebrates of the United States: Porifera to Crustacea |edition=4th |publisher=[[John Wiley and Sons]] |isbn=978-0-471-35837-4 |chapter-url=https://books.google.com/books?id=GqIctb8IqPoC&pg=PA468}}</ref> There is a single median [[compound eye]].<ref name="Belk"/> Most species show cyclical [[parthenogenesis]], where [[asexual reproduction]] is occasionally supplemented by [[sexual reproduction]], which produces resting eggs that allow the species to survive harsh conditions and disperse to distant habitats.<ref name="Decaestecker">{{cite book |editor1=Isa Schön |editor2=Koen Martens |editor3=Peter van Dijk |year=2009 |title=Lost Sex: The Evolutionary Biology of Parthenogenesis |publisher=[[Springer Science+Business Media|Springer]] |isbn=978-90-481-2769-6 |author=Ellen Decaestecker |author2=Luc De Meester |author3=Joachim Mergaey |chapter=Cyclical Parthenogenesis in Daphnia: Sexual Versus Asexual Reproduction |pages=295–316 |chapter-url=https://lirias.kuleuven.be/handle/123456789/208129 |doi=10.1007/978-90-481-2770-2_15|s2cid=82949264 }}</ref> In the water bodies of the world, a lot of [[Cladocera]] are non-native species, many of which pose a great threat to aquatic ecosystems.<ref>{{Cite journal |last1=Kotov |first1=Alexey A. |last2=Karabanov |first2=Dmitry P. |last3=Van Damme |first3=Kay |date=2022-09-09 |title=Non-Indigenous Cladocera (Crustacea: Branchiopoda): From a Few Notorious Cases to a Potential Global Faunal Mixing in Aquatic Ecosystems |journal=[[Water (journal)|Water]]|volume=14 |issue=18 |pages=2806 |doi=10.3390/w14182806 |issn=2073-4441 |doi-access=free}}</ref>

==Evolution==
The [[fossil record]] of branchiopods extends back at least into the [[Upper Cambrian]] and possibly further. The group is thought to be [[monophyly|monophyletic]], with the [[Anostraca]] having been the first group to [[cladogenesis|branch off]].<ref name="M&D">{{cite book |url=https://www.vliz.be/imisdocs/publications/121258.pdf |title=An Updated Classification of the Recent Crustacea |author1=Joel W. Martin  |author2=George E. Davis  |name-list-style=amp |year=2001 |pages=1–132 |publisher=[[Natural History Museum of Los Angeles County]]}}</ref> It is thought that the group evolved in the seas, but was forced into [[vernal pool|temporary pools]] and [[hypersaline lake]]s by the evolution of [[Osteichthyes|bony fishes]].<ref name="Belk"/> Although they were previously considered the [[sister group]] to the remaining crustaceans, it is now widely accepted that crustaceans form a paraphyletic group, and Branchiopoda are thought to be sister to a clade comprising [[Xenocarida]] ([[Remipedia]] and [[Cephalocarida]]) and [[Hexapoda]] ([[insect]]s and their relatives).<ref>{{cite journal |author=David R. Andrew |year=2011 |title=A new view of insectecrustacean relationships II. Inferences from expressed sequence tags and comparisons with neural cladistics |journal=[[Arthropod Structure & Development]] |volume=40 |issue= 3|pages=289–302 |doi=10.1016/j.asd.2011.02.001 |pmid=21315832|bibcode=2011ArtSD..40..289A }}</ref><ref>{{cite journal |author1=Bjoern M. von Reumont |author2=Ronald A. Jenner |author3=Matthew A. Wills |author4=Emiliano Dell'Ampio |author5=Günther Pass |author6=Ingo Ebersberger |author7=Benjamin Meyer |author8=Stefan Koenemann |author9=Thomas M. Iliffe |author10=Alexandros Stamatakis |author11=Oliver Niehuis |author12=Karen Meusemann |author13=Bernhard Misof |year=2012 |title=Pancrustacean phylogeny in the light of new phylogenomic data: support for Remipedia as the possible sister group of Hexapoda |journal=[[Molecular Biology and Evolution]] |volume=29 |issue=3 |pages=1031–1045 |doi=10.1093/molbev/msr270 |pmid=22049065 |url=http://eprints.cs.univie.ac.at/3232/ |format=[[Portable Document Format|PDF]] proofs|doi-access=free }}</ref>

==See also==
*''[[Vladicaris]]''

==References==
{{Reflist|32em|refs=
<ref name="Jørgensen">{{cite book |editor=Sven Erik Jørgensen  |title=Ecosystem Ecology |year=2009 |publisher=[[Academic Press]] |isbn=978-0-444-53466-8 |chapter=Saline and soda lakes |author=J. M. Melack |pages=380–384 |chapter-url=https://books.google.com/books?id=a-LjEvwWmOEC&pg=PA384}}</ref>

<ref name=Cuvier1831>{{cite book |series=The animal kingdom arranged in conformity with its organization |volume=3 |title=The Crustacea, Arachnides and Insecta |author=Pierre André Latreille |editor=Georges Cuvier |editor-link=Georges Cuvier |others=Henry M'Murtrie (trans.) |publisher=G. & C. & H. Carvill |year=1831 |url=https://books.google.com/books?id=vZM4AAAAMAAJ&q=branchiopoda|author-link=Pierre André Latreille }}</ref>

<ref name=worms>
{{Cite web| title=''Branchiopoda''
| url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=1069
| website=WoRMS, World Register of Marine Species
| access-date=2021-11-24
}}</ref>
}}

{{Arthropods}}
{{Branchiopoda}}
{{Taxonbar|from=Q188360}}
{{Authority control}}

[[Category:Branchiopoda| ]]
[[Category:Arthropod classes]]
[[Category:Extant Cambrian first appearances]]
[[Category:Taxa named by Pierre André Latreille]]