Remipedia

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Remipedes
Temporal range: Lower Pennsylvanian–Recent
Speleonectes tanumekes unlabeled.png
Speleonectes tanumekes
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Superclass: Allotriocarida
Class: Remipedia
J. Yager 1981
Orders & families
  • †Enantiopoda
    • †Tesnusocarididae
  • Nectiopoda

Remipedia is a class of blind crustaceans, closely related to hexapods, found in coastal aquifers which contain saline groundwater, with populations identified in almost every ocean basin so far explored, including in Australia, the Caribbean Sea, and the Atlantic Ocean. The first described remipede was the fossil Tesnusocaris goldichi (Lower Pennsylvanian). Since 1979, at least seventeen living species have been identified in subtropical regions around the world. [1]

Contents

Description

Remipedes are 1–4 centimetres (0.4–1.6 in) long and comprise a head and an elongate trunk of up to thirty-two similar body segments. [2] Pigmentation and eyes are absent. [3] Biramous swimming appendages are laterally present on each segment. The animals swim on their backs and are generally slow-moving. [4] They are the only known venomous crustaceans, and have fangs connected to secretory glands, which inject a combination of digestive enzymes and venom into their prey, [5] but they also feed through filter feeding. Being hermaphrodites, the female pore is located on the seventh trunk segment and the male pore on the fourteenth. [6]

Remipedia have a generally primitive body plan compared to other extant crustaceans, and are the only extant pancrustaceans to lack significant postcephalic tagmosis. [4] Previously regarded as 'primitive', Remipedia have since been shown to have enhanced olfactory nerve centers (a common feature for species that live in dark environments). [7]

Based on studies of the free-living larvae, they appear to be lecithotrophic (non-feeding). Mouths, guts, and anuses appear in the juvenile stage. Because of the energy and nutrients required for swimming, molting, and to grow in size and length, it has been speculated that the larvae may have other sources of growth than its yolk; possibly symbiotic bacteria. [8] [9]

With the exception of Speleonectes kakuki, which inhabits a fully marine, sub-seafloor cave in the Bahamas, all known species of remipedians have been found exclusively in anchialine cave systems. [10]

History of classification

The class Remipedia was erected in 1981 by Jill Yager, in describing Speleonectes lucayensis from the Bahamas. [11] The name "Remipedia" is from the Latin remipedes, meaning "oar-footed". [11]

Historical phylogeny based on morphology and physiology has placed Remipedia under Mandibulata, in the subphylum Crustacea, and distinct from Hexapoda.

New research in evolution and development reveals similarities between larvae and postembryonic development of remipedes and Malacostraca, singling Remipedia as a potential crustacean sister group of Hexapoda. Similarities in brain anatomy further support this affinity, and hexapod-type hemocyanins have been discovered in remipedes. [12]

Recent molecular studies have grouped Remipedia with Cephalocarida, Branchiopoda, and Hexapoda in a clade named Allotriocarida. [13] [14] Remipedia was found as the sister group to Hexapoda both in phylogenomic [15] [14] and combined morphological and transcriptome studies. [13] In other studies Remipedia and Cephalocarida are grouped together form the clade Xenocarida, which in turn was sister to Hexapoda in a clade named Anartiopoda [16] or Miracrustacea ('surprising crustaceans'). [4]

The relationship of Remipedia and other crustacean classes and insects is shown in the following phylogenetic tree, which shows Allotriocarida, along with Oligostraca and Multicrustacea, as the three main divisions of subphylum Pancrustacea, embracing the traditional crustaceans and the hexapods (including insects). [14]

Pancrustacea

Oligostraca

Multicrustacea

Thecostraca

Copepoda

Malacostraca

Allotriocarida

Cephalocarida

Branchiopoda

Remipedia

Hexapoda

Protura

Diplura

Collembola

Insecta

Classification

Thirty extant species are recognized as of early 2022, divided among eight families and twelve genera. [17] [18] All are placed in the order Nectiopoda. The second order, Enantiopoda, comprises the fossil species Tesnusocaris goldichi and Cryptocaris hootchi . [1]

Geographic distribution of extant Remipedia

Related Research Articles

<span class="mw-page-title-main">Branchiopoda</span> Class of crustaceans

Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca, Notostraca and the Devonian Lepidocaris. They are mostly small, freshwater animals that feed on plankton and detritus.

<span class="mw-page-title-main">Malacostraca</span> Largest class of crustaceans

Malacostraca is the second largest of the six classes of crustaceans just behind hexapods, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, amphipods, mantis shrimp, tongue-eating lice and many other less familiar animals. They are abundant in all marine environments and have colonised freshwater and terrestrial habitats. They are segmented animals, united by a common body plan comprising 20 body segments, and divided into a head, thorax, and abdomen.

<span class="mw-page-title-main">Stenopodidea</span> Infraorder of crustaceans

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.

<i>Tesnusocaris</i> Extinct genus of crustaceans

Tesnusocaris goldichi is an extinct species of remipedian crustacean that lived in the Pennsylvanian period, the one of the two representatives of the extinct remipedian order Enantiopoda. Its fossil is from the Lower Pennsylvanian Tesnus formation, Texas. The other known enantiopod remipedian is Cryptocaris hootchi of the Mazon Creek fauna.

Atelocerata is a proposed clade of arthropods that includes Hexapoda and Myriapoda, but excludes Crustacea and Chelicerata. The name is currently used interchangeably with Tracheata. or Uniramia sensu stricto. It is an extensive division of arthropods comprising all those that breathe by tracheae, as distinguished from Crustacea, which breathe by means of gills.

<span class="mw-page-title-main">Pancrustacea</span> Clade comprising all crustaceans and hexapods

Pancrustacea is the clade that comprises all crustaceans, including hexapods. This grouping is contrary to the Atelocerata hypothesis, in which Hexapoda and Myriapoda are sister taxa, and Crustacea are only more distantly related. As of 2010, the Pancrustacea taxon was considered well accepted, with most studies recovering Hexapoda within Crustacea. The clade has also been called Tetraconata, referring to having four cone cells in the ommatidia. This name is preferred by some scientists as a means of avoiding confusion with the use of "pan-" to indicate a clade that includes a crown group and all of its stem group representatives.

<span class="mw-page-title-main">Speleonectidae</span> Family of crustaceans

Speleonectidae is a family of remipedes in the order Nectiopoda. There are at least two genera and about seven described species in Speleonectidae.

Godzilliidae is a family of remipedes in the order Nectiopoda. There are at least two genera and four described species in Godzilliidae.

<span class="mw-page-title-main">Mandibulata</span> Clade of arthropods

Mandibulata, is one of two major clades of living arthropods alongside Chelicerata. It comprises the extant groups Myriapoda and Pancrustacea. The name "Mandibulata" refers to the mandibles, a modified pair of limbs used in food processing, the presence of which are characteristic of most members of the group. Members of the group are referred to as mandibulates.

Morlockia atlantida is a species of eyeless crustacean in the order Nectiopoda. It was discovered in August 2009 in the Túnel de la Atlántida, the world's longest submarine lava tube on Lanzarote in the Canary Islands off the west coast of North Africa. Originally named Speleonectes atlantida, it was transferred to genus Morlockia in 2012. Like other remipedes, the species is equipped with venomous fangs.

Xenocarida is a proposed clade inside the subphylum Crustacea that comprises two classes that were discovered in the 20th century: Remipedia and Cephalocarida. Both groups are marine hermaphrodites. The clade was recovered as the sister groups to Hexapoda.

<span class="mw-page-title-main">Crustacean larva</span> Crustacean larval and immature stages between hatching and adult form

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 of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.

Godzilliognomus schrami is a species of Remipedia discovered in 2007, representing one of five extant species of the family Godzilliidae. It generally reaches about 7 millimetres (0.28 in) in length and inhabits a single anchialine cave on Eleuthera Island. The specific epithet commemorates Frederick Schram.

<i>Karstarma</i> Genus of crabs

Karstarma is a genus of karst-dwelling crabs formerly included in Sesarmoides.

<span class="mw-page-title-main">Hexapoda</span> Subphylum of arthropods

The subphylum Hexapoda or hexapods comprises the largest clade of arthropods and includes most of the extant arthropod species. It includes the crown group Insecta, as well as three much smaller groups of wingless arthropods that were once considered insects: Collembola (springtails), Protura (coneheads) and Diplura. The insects and springtails are very abundant and are some of the most important pollinators, basal consumers, scavengers/detritivores and micropredators in terrestrial environments.

<span class="mw-page-title-main">Crustacean</span> Subphylum of arthropods

Crustaceans belong to the subphylum Crustacea, and form a large, diverse group of arthropods including decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans.

<i>Xibalbanus tulumensis</i> Species of crustacean

Xibalbanus tulumensis is a venomous, hermaphroditic crustacean found in anchialine caves on the Yucatán Peninsula in the Caribbean Sea. This blind remipede liquefies the body contents of other crustaceans with a venom similar to that of rattlesnakes, and which includes digestive enzymes and a paralysing toxin.

Pleomothra is a genus of crustacean found in the Caribbean. First described in 1989, the genus has 2 identified species as of 2008. It is the sole member of family Pleomothridae, but was previously placed in family Godzilliidae.

<span class="mw-page-title-main">Multicrustacea</span> Superclass of crustaceans

The clade Multicrustacea constitutes the largest superclass of crustaceans, containing approximately four-fifths of all described crustacean species, including crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, barnacles, copepods, amphipods, mantis shrimp and others. The largest branch of multicrustacea is the class Malacostraca.

Morlockia is a genus of eyeless crustaceans in the family Morlockiidae. The genus contains 4 described species.

References

  1. 1 2 Stefan Koenemann; Frederick R. Schram; Mario Hönemann & Thomas M. Iliffe (2007). "Phylogenetic analysis of Remipedia (Crustacea)". Organisms Diversity & Evolution . 7 (1): 33–51. doi:10.1016/j.ode.2006.07.001.
  2. Cameron McCormick (November 10, 2008). "Remipedia". The Lord Geekington.
  3. Yager, J. (18 September 2013). "Lasionectes entrichoma Yager & Schram, 1986". tamug.edu. Retrieved 9 February 2018.
  4. 1 2 3 Regier, Jerome C.; Shultz, Jeffrey W.; Zwick, Andreas; Hussey, April; Ball, Bernard; Wetzer, Regina; Martin, Joel W.; Cunningham, Clifford W. (February 2010). "Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences". Nature. 463 (7284): 1079–1083. Bibcode:2010Natur.463.1079R. doi:10.1038/nature08742. ISSN   0028-0836. PMID   20147900. S2CID   4427443.
  5. Kaplan, Matt (22 October 2013). "First venomous crustacean discovered". Nature News . doi:10.1038/nature.2013.13985. S2CID   87091184 . Retrieved 10 May 2015.
  6. Behavior of Remipedia in the Laboratory, with Supporting Field Observations
  7. Martin Fanenbruck; Steffen Harzsch & Johann Wolfgang Wägele (2004). "The brain of the Remipedia (Crustacea) and an alternative hypothesis on their phylogenetic relationships". Proceedings of the National Academy of Sciences . 101 (11): 3868–3873. doi: 10.1073/pnas.0306212101 . PMC   374336 . PMID   15004272.
  8. Treatise on Zoology - Anatomy, Taxonomy, Biology. The Crustacea, Volume 4 part A
  9. Evolution and Phylogeny of Pancrustacea: A Story of Scientific Method
  10. Global Biodiversity and Phylogenetic Evaluation of Remipedia (Crustacea)
  11. 1 2 Jill Yager (August 1981). "Remipedia, a new class of Crustacea from a marine cave in the Bahamas". Journal of Crustacean Biology . 1 (3): 328–333. doi:10.2307/1547965. JSTOR   1547965.
  12. Giribet, Gonzalo; Edgecombe, Gregory D. (2012-01-07). "Reevaluating the Arthropod Tree of Life". Annual Review of Entomology. 57 (1): 167–186. doi:10.1146/annurev-ento-120710-100659. ISSN   0066-4170. PMID   21910637. S2CID   207597767.
  13. 1 2 Oakley, Todd H.; Wolfe, Joanna M.; Lindgren, Annie R.; Zaharoff, Alexander K. (2013). "Phylotranscriptomics to Bring the Understudied into the Fold: Monophyletic Ostracoda, Fossil Placement, and Pancrustacean Phylogeny". Molecular Biology and Evolution. 30: 215–233. doi: 10.1093/molbev/mss216 . PMID   22977117.
  14. 1 2 3 Lozano-Fernandez, Jesus; Giacomelli, Mattia; Fleming, James F.; Chen, Albert; Vinther, Jakob; Thomsen, Philip Francis; Glenner, Henrik; Palero, Ferran; Legg, David A.; Iliffe, Thomas M.; Pisani, Davide; Olesen, Jørgen (2019). "Pancrustacean Evolution Illuminated by Taxon-Rich Genomic-Scale Data Sets with an Expanded Remipede Sampling". Genome Biology and Evolution. 11 (8): 2055–2070. doi:10.1093/gbe/evz097. PMC   6684935 . PMID   31270537.
  15. Bjoern M. von Reumont; Ronald A. Jenner; Matthew A. Wills; Emiliano Dell'Ampio; Günther Pass; Ingo Ebersberger; Benjamin Meyer; Stefan Koenemann; Thomas M. Iliffe; Alexandros Stamatakis; Oliver Niehuis; Karen Meusemann & Bernhard Misof (March 2012). "Pancrustacean phylogeny in the light of new phylogenomic data: support for Remipedia as the possible sister group of Hexapoda". Molecular Biology and Evolution . 29 (3): 1031–1045. doi: 10.1093/molbev/msr270 . PMID   22049065.
  16. Engel, Michael (2015). "Insect evolution". Current Biology. 25 (19): R868–R872. doi: 10.1016/j.cub.2015.07.059 . PMID   26439349. S2CID   14406214.
  17. Koenemann, S.; Hoenemann, M.; Stemme T. (2022). "World Remipedia Database". Vlaams Instituut voor de Zee . Retrieved 7 February 2022.
  18. World Remipedia Database. "Remipedia". World Register of Marine Species . Retrieved 7 February 2022.
  19. Dennis Hazerli; Stefan Koenemann & Thomas M. Iliffe (2010). "Cryptocorynetes elmorei, a new species of Remipedia (Crustacea) from an anchialine cave on Eleuthera, Bahamas". Marine Biodiversity . 40 (2): 71–78. doi:10.1007/s12526-009-0033-4. S2CID   8082592.
  20. Tamara R. Hartke; Stefan Koenemann & Jill Yager (2011). "Speleonectes williamsi, a new species of Remipedia (Crustacea) from the Bahamas" (PDF excerpt). Zootaxa . 3115: 21–28. doi:10.11646/zootaxa.3115.1.2.
  21. Yager J (2013). "Speleonectes cokei, new species of Remipedia (Crustacea: Speleonectidae) from a submerged ocean cave near Caye Chapel, Belize". Zootaxa. 3710 (4): 354–362. doi:10.11646/zootaxa.3710.4.4. PMID   26106696. S2CID   10850210.
  22. Marco T. Neiber; Finja C. Hansen; Thomas M. Iliffe; Brett C. Gonzalez & Stefan Koenemann (2012). "Molecular taxonomy of Speleonectes fuchscockburni, a new pseudocryptic species of Remipedia (Crustacea) from an anchialine cave system on the Yucatán Peninsula, Quintana Roo, Mexico" (PDF excerpt). Zootaxa . 3190: 31–46. doi:10.11646/zootaxa.3190.1.2.
  23. Lorentzen, Dörte; Koenemann, Stefan; Iliffe, Thomas M. (2007). "Speleonectes emersoni, A New Species of Remipedia (Crustacea) from the Dominican Republic". Zootaxa. 1543: 61–68. doi:10.11646/zootaxa.1543.1.3.