(Redirected from 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]

Temporal range: Lower Pennsylvanian–Recent
Speleonectes tanumekes unlabeled.png
Speleonectes tanumekes
Scientific classification e
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Superclass: Allotriocarida
Class: Remipedia
J. Yager 1981
Orders & families
  • †Enantiopoda
    • †Tesnusocarididae
  • Nectiopoda


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, molt several times 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]

History of classificationEdit

The class Remipedia was erected in 1981 by Jill Yager, in describing Speleonectes lucayensis from the Bahamas.[10] The name "Remipedia" is from the Latin remipedes, meaning "oar-footed".[10]

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.[11]

Recent molecular studies have grouped Remipedia with Cephalocarida, Branchiopoda, and Hexapoda in a clade named Allotriocarida.[12][13] Remipedia was found as the sister group to Hexapoda both in phylogenomic[14] [13] and combined morphological and transcriptome studies.[12] 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[15] 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).[13]

















Thirty extant species are recognized as of early 2022, divided among eight families and twelve genera.[16][17] 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 RemipediaEdit


  1. ^ a b 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". Retrieved 9 February 2018.
  4. ^ a b c 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. ^ a b 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.
  11. ^ 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.
  12. ^ a b 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.
  13. ^ a b c 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.
  14. ^ 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.
  15. ^ Engel, Michael (2015). "Insect evolution". Current Biology. 25 (19): R868–R872. doi:10.1016/j.cub.2015.07.059. PMID 26439349. S2CID 14406214.
  16. ^ Koenemann, S.; Hoenemann, M.; Stemme T. (2022). "World Remipedia Database". Vlaams Instituut voor de Zee. Retrieved 7 February 2022.
  17. ^ World Remipedia Database. "Remipedia". World Register of Marine Species. Retrieved 7 February 2022.
  18. ^ 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.
  19. ^ 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.
  20. ^ 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.
  21. ^ 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.
  22. ^ 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.

External linksEdit