Tantulocarida

Tantulocarida
Microdajus sp.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Superclass:	Multicrustacea
Class:	Tantulocarida G. A. Boxshall & R. J. Lincoln, 1983 [1]
Families
Basipodellidae Cumoniscidae (formerly Deoterthridae) Doryphallophoridae Microdajidae Onceroxenidae

Tantulocarida is a highly specialised group of parasitic crustaceans that consists of about 33 species, treated as a class in superclass Multicrustacea. They are typically ectoparasites that infest copepods, isopods, tanaids, amphipods and ostracods.^[2][3]

Description

In the Tantulocarida, animals do not ever present eyes.^[4]

The tantulus larvae has a head with a ventral oral disc but no appendages, a six-segmented thorax with six pairs of legs, and a limbless abdomen consisting of one to six segments in addition to a telson.^[5]

Body length

Members of this subclass are minute – less than 0.3 millimetres (0.012 in) in length and have a dramatic reduction in body form compared to other crustaceans, with an unsegmented, sac-like thorax and a much reduced abdomen.^[6] One tantulocarid species, Tantulacus dieteri, is the world's smallest arthropod, with a total body length of only 85 micrometres (0.0033 in).^[7]

Life cycle

The tantulocarid life cycle is unique among crustaceans. The tantulus larva transforms directly from a non-feeding (lecithotrophic) and free-swimming organism into a parasite without any instars. When entering the parasitic stage much of the body, such as the muscles, degenerates, even if the body itself becomes bigger. As a parasite it is permanently attached to its host, and after piercing its host's cuticle with an unpaired stylet, a rootlet system used to absorb nutrients enters through the hole and grow into the host’s tissue. The adult form develops inside the larva, and can become either a sac-like parthenogenetic female, or a fully developed free-living, non-feeding and sexually-reproducing male or female.^{[8][9][10][11][12]} The eggs inside the parthenogenetic female are eventually released as fully developed tantulus larvae. The finding of what appears to be a benthic non-feeding nauplius larva suggests that eggs produced by sexual females hatch as nauplii instead of tantulus larvae. Both the parthenogenetic and sexual females are semelparous.^[13]

Classification

Five families are recognised:^[14]

Basipodellidae Boxshall & Lincoln, 1983:[15] Basipodella Becker, 1975 Hypertantulus Ohtsuka & Boxshall, 1998 Nipponotantulus Huys, Ohtsuka & Boxshall, 1994 Polynyapodella Huys, Møberg & Kristensen, 1997 Rimitantulus Huys & Conroy-Dalton, 1997 Serratotantulus Savchenko & Kolbasov, 2009 Stygotantulus Boxshall & Huys, 1989 Doryphallophoridae Huys, 1991:[16] Doryphallophora Huys, 1990 Paradoryphallophora Ohtsuka & Boxshall, 1998 Microdajidae Boxshall & Lincoln, 1987:[17] Microdajus Greve, 1965 Xenalytus Huys, 1991

Cumoniscidae Nierstrasz & Brender à Brandis, 1923 (formerly family Deoterthridae:[18] Amphitantulus Boxshall & Vader, 1993 Aphotocentor Huys, 1991 Arcticotantulus Kornev, Tchesunov & Rybnikov, 2004 Boreotantulus Huys & Boxshall, 1988 Campyloxiphos Huys, 1991 Coralliotantulus Huys, 1991 Cumoniscus Bonnier, 1903 Deoterthron Bradford & Hewitt, 1980 Dicrotrichura Huys, 1989 Itoitantulus Huys, Ohtsuka Boxshall & Itô, 1992 Tantulacus Huys, Andersen & Kristensen, 1992 Onceroxenidae Huys, 1991:[19] Onceroxenus Boxshall & Lincoln, 1987

References

1. "Tantulocarida". Integrated Taxonomic Information System.
2. "WoRMS - World Register of Marine Species - Tantulocarida". www.marinespecies.org. Retrieved 2019-06-28.
3. Geoffrey A. Boxshall & Roger J. Lincoln (February 1983). "Tantulocarida, a new class of Crustacea ectoparasitic on other crustaceans". Journal of Crustacean Biology. 3 (1): 1–16. doi:10.2307/1547849. JSTOR 1547849.
4. Oakley, T. H.; Cunningham, C. W. (2002). "Molecular phylogenetic evidence for the independent evolutionary origin of an arthropod compound eye". Proceedings of the National Academy of Sciences of the United States of America. 99 (3): 1426–1430. Bibcode:2002PNAS...99.1426O. doi:10.1073/pnas.032483599. PMC 122207. PMID 11818548.
5. Multicellular Animals: Volume II: The Phylogenetic System of the Metazoa
6. "Tantulocarida". AccessScience Encyclopedia. McGraw-Hill. Archived from the original on 2011-06-17. Retrieved 2016-09-10.
7. Inga Mohrbeck, Pedro Martínez Arbizu & Thomas Glatzel (October 2010). "Tantulocarida (Crustacea) from the Southern Ocean deep sea, and the description of three new species of Tantulacus Huys, Andersen & Kristensen, 1992". Systematic Parasitology. 77 (2): 131–151. doi:10.1007/s11230-010-9260-0. PMID 20852984. S2CID 7325858.
8. G. A. Boxshall & R. J. Lincoln (June 11, 1987). "The life cycle of the Tantulocarida (Crustacea)". Philosophical Transactions of the Royal Society B. 315 (1173): 267–303. Bibcode:1987RSPTB.315..267B. doi:10.1098/rstb.1987.0009. JSTOR 2396610.
9. Petrunina, Alexandra S.; Kolbasov, Gregory A.; Martinez Arbizu, Pedro (2019). "Anatomy of the free tantulus larva (Crustacea: Tantulocarida) studied with confocal laser scanning microscopy: An extreme case of miniatuarisation in the Arthropoda". Progress in Oceanography. 178. Bibcode:2019PrOce.17802190P. doi:10.1016/j.pocean.2019.102190.
10. Itoitantulus misophricola gen. et sp. nov.: First Record of Tantulocarida (Crustacea: Maxillopoda) in the North Pacific Region
11. Huys, Rony; Boxshall, Geoffrey A.; Lincoln, Roger J. (1993). "The Tantulocaridan Life Cycle: the Circle Closed?". Journal of Crustacean Biology. 13 (3): 432–442. doi:10.2307/1548786. ISSN 0278-0372. JSTOR 1548786.
12. Anatomy of the Tantulocarida: first results obtained using TEM and CLSM. Part I: tantulus larva - GfBS
13. Atlas of Crustacean Larvae
14. WoRMS. "Tantulocarida". World Register of Marine Species. Retrieved 13 December 2022.
15. Geoff Boxshall (August 20, 2008). T. Chad Walter & Geoff Boxshall (ed.). "Basipodellidae". World Copepoda database. World Register of Marine Species. Retrieved 2016-09-10.
16. Geoff Boxshall (August 20, 2008). T. Chad Walter & Geoff Boxshall (ed.). "Doryphallophoridae". World Copepoda database. World Register of Marine Species. Retrieved 2016-09-10.
17. Geoff Boxshall (August 20, 2008). T. Chad Walter & Geoff Boxshall (ed.). "Microdajidae". World Copepoda database. World Register of Marine Species. Retrieved 2016-09-10.
18. WoRMS. "Cumoniscidae Nierstrasz & Brender à Brandis, 1923". World Register of Marine Species. Retrieved 13 December 2022.
19. Geoff Boxshall (2012). Walter TC, Boxshall G (eds.). "Onceroxenidae". World of Copepods database. World Register of Marine Species. Retrieved 2016-09-10.

External links

• Data related to Tantulocarida at Wikispecies