Paxillosida

Paxillosida
Luidia magnifica
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Echinodermata
Class: Asteroidea
Superorder: Valvatacea
Order: Paxillosida
Perrier, 1884
Families

See text

The Paxillosida are a large order of sea stars.

Characteristics

Paxillosida adults lack an anus and have no suckers on their tube feet. They do not develop the brachiolaria stage in their early development, and use the larval tube feet to attach to the seafloor when they settle out of the plankton instead of the attachment complex seen in other starfish species. They possess marginal plates, and have sessile pedicellariae. They mostly inhabit soft-bottomed environments of sand or mud.

The order are found globally and occupy a wide bathymetric range. In the exclusively bathyal and abyssal Porcellanasteridae, includes some of the deepest dwelling of all Asteroidea. The Porcellanasteridae is principally infaunal, with species generally found living buried beneath the surface of soft, generally muddy, substrate. In this, and in the similarly infaunal families Ctenodiscidae and Goniopectinidae, species have developed specialised intermarginal fascioles known as cribiform organs which act as respiratory 'pumps' that draw in water to produce a current around the animal when it is buried.

Systematics

The taxonomic position of the Paxillosida is not yet fully resolved, in part due to disagreement as to whether the unusual characters of paxillosid larvae and tube-feet represent the ancestral state for Asteroidea or are derived for living on soft sediments. More recent analyses supports a more derived position and suggest that they may be a sister taxon to the Valvatida.

The order is currently divided into the following families:

References

  1. 1 2 Carter, Hugh F.; White, Tom S. (2026-10-01). "Illustrated catalogue of the type Asteroidea in the Natural History Museum, London. Part II. Valvatacea: Paxillosida". Systematics and Biodiversity. 24 (2) 2686803. Taylor & Francis. doi:10.1080/14772000.2026.2686803. ISSN 1477-2000.
  2. 1 2 Matsubara, M., Komatsu, M., Araki, T., Asakawa, S., Yokobori, S.-I., Watanabe, K. & Wada, H. (2005) The phylogenetic status of Paxillosida (Asteroidea) based on complete mitochondrial DNA sequences. Molecular Genetics and Evolution, 36, 598–605
  3. ↑ Carter, Hugh F; Thompson, Jeffrey R; Elphick, Maurice R; Oliveri, Paola (2021-08-01). "The Development and Neuronal Complexity of Bipinnaria Larvae of the Sea Star Asterias rubens". Integrative and Comparative Biology. 61 (2): 337–351. doi:10.1093/icb/icab103. ISSN 1540-7063. PMC 8427176. PMID 34048552.
  4. ↑ Byrne, Maria (2013). "Asteroid Evolutionary Developmental Biology". In Lawrence, John (ed.). Starfish: Biology & ecology of the asteroidea. Johns Hopkins University Press. ISBN 978-1421407876.
  5. ↑ Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. p. 948. ISBN 0-03-056747-5.
  6. ↑ Carter, H. F.; Bribiesca-Contreras, G.; Williams, S. T. (October 2025). "Deep-sea-floor diversity in Asteroidea is shaped by competing processes across different latitudes and oceans". Nature Ecology & Evolution. 9 (10). Nature Publishing Group: 1910–1923. Bibcode:2025NatEE...9.1910C. doi:10.1038/s41559-025-02808-2. ISSN 2397-334X. PMC 12507690. PMID 40781200.
  7. ↑ Shick, J. Malcolm (1983). "Respiratory Gas Exchange in Echinoderms". Echinoderm Studies. 1: 67–110. doi:10.1201/9781003079071-4. ISBN 978-1-003-07907-1.{{cite journal}}: CS1 maint: periodical has ISBN (link)
  8. ↑ GALE, ANDREW SCOTT (1987-02-01). "Phylogeny and classification of the Asteroidea (Echinodermata)". Zoological Journal of the Linnean Society. 89 (2): 107–132. doi:10.1111/j.1096-3642.1987.tb00652.x. ISSN 0024-4082.
  9. ↑ Blake, Dan (1988). "Paxillosidans are not primitive asteroids: A hypothesis based on functional considerations". Echinoderm Biology: 309–314.
  10. ↑ Jossart, Quentin; Kochzius, Marc; Danis, Bruno; Moreau, Camille; Schon, Isa; Fourdrilis, Severine; Dettai, Agnes (2024). "Implications of extensive addition of new mitogenomes for sea star phylogenetics and evolution (Echinodermata: Asteroidea)". Zoological Journal of the Linnean Society. 202 (4).
  11. ↑ MarineSpecies.org - Paxillosida Perrier, 1884