branchiopoda

Members of the Branchiopoda are unified by the presence of gills on many of the animals' appendages, including some of the mouthparts. This is also responsible for the name of the group{{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 }} (from the {{langx|grc|βράγχια}}, gills, akin to {{lang|grc|βρόγχος}}, windpipe; {{langx|el|πούς}}, foot).{{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 }} They generally possess compound eyes 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).{{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 }} In the groups where the carapace prevents the use of the trunk limbs for swimming (Cladocera and clam shrimp), the antennae are used for locomotion, as they are in the nauplius. Male fairy shrimp have an enlarged pair of antennae with which they grasp the female during mating, while in the bottom-feeding Notostraca, the antennae are reduced to vestiges. 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.

Branchiopods are found in continental fresh water, including temporary pools and in hypersaline lakes, and some in brackish water. Only two groups of water fleas include marine species: Family Podonidae in the order Diplostraca, and family Sididae in the order Diplostraca.{{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}}[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][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]

Most branchiopodans eat floating detritus or plankton, which they take using the setae on their appendages. But notostracans are omnivorous and very opportunistic feeders and will eat algae and bacteria in addition to animals as both predators and scavengers.{{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}}

In early taxonomic treatments, the current members of the Branchiopoda were all placed in a single genus, Monoculus. The taxon Branchiopoda was erected by Pierre André Latreille in 1817, initially at the rank of order.

The current upper-level classification of Branchiopoda, according to the World Register of Marine Species (2021), is as follows:

Class Branchiopoda Latreille, 1817

: Subclass Sarsostraca Tasch, 1969

::Order Anostraca Sars, 1867

:::Suborder Anostracina Weekers et al., 2002

:::Suborder Artemiina Weekers et al., 2002

: Subclass Phyllopoda Preuss, 1951

:: Superorder Diplostraca Gerstaecker, 1866

::: Order Anomopoda G.O. Sars, 1865

::: Order Ctenopoda G.O. Sars, 1865

::: Order Cyclestherida Sars G.O., 1899

::: Order Haplopoda G.O. Sars, 1865

::: Order Laevicaudata Linder, 1945

::: Order Onychopoda G.O. Sars, 1865

::: Order Spinicaudata Linder, 1945

:: Order Notostraca G. O. Sars, 1867

::Genus †Rehbachiella? Müller, 1983

In addition, the extinct genus Lepidocaris is generally placed in Branchiopoda.

File:Artemia salina 3.jpg (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}}). Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia (swimming legs), and the body lacks a carapace.{{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}} They live in vernal pools and hypersaline lakes across the world, including pools in deserts, in ice-covered mountain lakes and in Antarctica. They swim "upside-down" and feed by filtering organic particles from the water or by scraping algae from surfaces. They are an important food for many birds and fish, and are cultured and harvested for use as fish food. There are 300 species spread across 8 families.{{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 }}

{{Main|Lepidocaris}}

Lipostraca contains a single extinct Early Devonian species, Lepidocaris rhyniensis,{{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}} which is the most abundant animal in the Rhynie chert deposits.{{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}} It resembles modern Anostraca, to which it is probably closely related, although its relationships to other orders remain unclear.{{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 }} The body is {{convert|3|mm|abbr=on}} long, with 23 body segments and 19 pairs of appendages, but no carapace.{{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 }} It occurred chiefly among charophytes, probably in alkaline temporary pools.{{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}}

{{Main|Notostraca}}

The order Notostraca comprises the single family Triopsidae, containing the tadpole shrimp or shield shrimp.{{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 }} The two genera, Triops and Lepidurus, are considered living fossils, having not changed significantly in outward form since the Triassic. They have a broad, flat carapace, which conceals the head and bears a single pair of compound eyes. The abdomen is long, appears to be segmented and bears numerous pairs of flattened legs. The telson is flanked by a pair of long, thin caudal rami. Phenotypic plasticity within taxa makes species-level identification difficult, and is further compounded by variation in the mode of reproduction.{{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}} The evidence of phenotypic plasticity of Arctic tadpole shrimp (Lepidurus arcticus, Notostraca) has been observed in Svalbard.{{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}} Notostracans are the largest branchiopodans and are omnivores living on the bottom of temporary pools, ponds{{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}} and shallow lakes.

{{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 legs which also carry gills. A strong muscle can close the two halves of the shell together.

File:Daphnia pulex.png (Cladocera: Daphniidae)]]

These four orders make up a group of small crustaceans commonly called water fleas. Around 620 species have been recognised so far, with many more undescribed.{{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 }} They are ubiquitous in inland aquatic habitats, but rare in the oceans.{{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}} 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.{{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}} There is a single median compound eye. 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.{{cite book |editor1=Isa Schön |editor2=Koen Martens |editor3=Peter van Dijk |year=2009 |title=Lost Sex: The Evolutionary Biology of Parthenogenesis |publisher=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 }} 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.{{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|volume=14 |issue=18 |pages=2806 |doi=10.3390/w14182806 |issn=2073-4441 |doi-access=free}}

The fossil record of branchiopods extends back at least into the Upper Cambrian and possibly further. The group is thought to be monophyletic, with the Anostraca having been the first group to branch off.{{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}} It is thought that the group evolved in the seas, but was forced into temporary pools and hypersaline lakes by the evolution of bony fishes. 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 (insects and their relatives).{{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 }}{{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=PDF proofs|doi-access=free }}

• Vladicaris

{{Reflist|32em|refs=

{{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}}

{{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 }}

{{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

}}

}}

{{Arthropods}}

{{Branchiopoda}}

{{Taxonbar|from=Q188360}}

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Category:Arthropod classes

Category:Extant Cambrian first appearances

Category:Taxa named by Pierre André Latreille