Dodecolopoda

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Dodecolopoda
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Pycnogonida
Order: Pantopoda
Family: Colossendeidae
Genus: Dodecolopoda
Calman & Gordon, 1933
Species:
D. mawsoni
Binomial name
Dodecolopoda mawsoni
Calman & Gordon, 1933

Dodecolopoda is a monotypic genus of sea spider (class Pycnogonida) in the family Colossendeidae.[1] The only species in this genus is Dodecolopoda mawsoni,[1] first described by William Thomas Calman and Isabella Gordon in 1933 based on a male holotype found off the coast of MacRobertson Land.[2] Calman and Gordon named this species for Sir Douglas Mawson, who obtained this specimen on his voyage to the Antarctic region in 1931.[2]

Description[edit]

This species is notable as one of only two species of sea spider with six pairs of legs (instead of the usual four leg pairs) and the first such species to be discovered.[3][4] This sea spider is also notable for its gigantic size, measuring 20 inches from tip to tip of its legs when fully extended.[2] The leg of the fourth pair on the holotype, for example, measures 240.3 mm in length.[2] The sea spider's long legs act as stilts, holding its body well above the surface below.[5]

These sea spiders resemble the ten-legged species in the genus Decolopoda but feature a longer proboscis compared to the trunk, a longer tarsus and shorter claw compared to the propodus, and setose legs, as well as more legs and a much larger size.[2] Both of these polymerous (i.e., extra-legged) genera resemble the eight-legged species in the genus Colossendeis (e.g., C. wilsoni) but retain chelifores as adults.[4] Phylogenetic analysis indicates that both Dodecolopoda and Decolopoda are nested within the genus Colossendeis in a phylogenetic tree, so that Colossendeis is paraphyletic with respect to these two polymerous genera.[6]

Distribution[edit]

This species is found in the Indian and Atlantic regions of the Southern Ocean and is endemic to the Antarctic region.[7][8]

References[edit]

  1. ^ a b "PycnoBase - Dodecolopoda Calman & Gordon, 1933". www.marinespecies.org. Retrieved 2024-02-21.
  2. ^ a b c d e Calman, William Thomas; Gordon, Isabella (1933-06-01). "A dodecapodous pycnogonid". Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character. 113 (781): 107–115. doi:10.1098/rspb.1933.0034.
  3. ^ Crooker, Allen (2008). "Sea Spiders (Pycnogonida)". In Capinera, John L. (ed.). Encyclopedia of Entomology. Dordrecht, NL: Springer Netherlands. pp. 3321–3335. doi:10.1007/978-1-4020-6359-6_4098. ISBN 978-1-4020-6359-6.
  4. ^ a b Hedgpeth, Joel W. (1947). "On the evolutionary significance of the Pycnogonida". Smithsonian Miscellaneous Collections. 106 (18): 1–53. hdl:10088/22801 – via Smithsonian Research Online.
  5. ^ Schram, Frederick R.; Hedgpeth, Joel W. (1978). "Locomotory mechanisms in Antarctic pycnogonids". Zoological Journal of the Linnean Society. 63 (1–2): 145–170. doi:10.1111/j.1096-3642.1978.tb02095.x. ISSN 0024-4082.
  6. ^ Dietz, Lars; Dömel, Jana S.; Leese, Florian; Mahon, Andrew R.; Mayer, Christoph (2019-07-01). "Phylogenomics of the longitarsal Colossendeidae: The evolutionary history of an Antarctic sea spider radiation". Molecular Phylogenetics and Evolution. 136: 206–214. doi:10.1016/j.ympev.2019.04.017. ISSN 1055-7903. PMID 31002869.
  7. ^ Soler-Membrives, Anna; Munilla, Tomás; Arango, Claudia P.; Griffiths, Huw (2014). "Southern Ocean biogeographic patterns in Pycnogonida" (PDF). Biogeographic Atlas of the Southern Ocean. ch. 5.14. Cambridge: Scientific Committee on Antarctic Research: 138–141 [139]. ISBN 978-0-948277-28-3.
  8. ^ "Dodecolopoda mawsoni". www.sealifebase.ca. Retrieved 2024-02-22.