Forcipulatida Explained

The Forcipulatida are an order of sea stars, containing three families and 49 genera.

Description

Forcipulatids share with the brisingid sea stars distinctive pedicellariae, consisting of a short stalk with three skeletal ossicles. Unlike that group, however, the forcipulatids tend to have more robust bodies.^[1] The order includes some well-known species, such as the common starfish, Asterias rubens. This order can be commonly found from North Carolina in the United States all the way to Santos in Brazil.^[2]

Phylogeny

The order is divided into three families:^[3]

• Family Asteriidae — 39 genera
• Family Heliasteridae — two genera
• Family Zoroasteridae — eight genera

World Register of Marine Species gives another taxonomy, with 7 families and 64 genera:

• Family Asteriidae Gray, 1840
• Family Heliasteridae Viguier, 1878
• Family Pedicellasteridae Perrier, 1884
• Family Pycnopodiidae Fisher, 1928
• Family Stichasteridae Perrier, 1885
• Family Zoroasteridae Sladen, 1889

A 2020 study involving phylogenetic analysis and scanning electron microscopy of the skeleton and ossicles of taxa from the superorder Forcipulatacea recovered Asteriidae, Stichasteridae, Zoroasteridae, and Brisingida as monophyletic.^[4]

See also

• Paulasterias mcclaini
• Paulasterias tyleri

Further reading

• Mah, C. & D. Foltz. (2011). Molecular Phylogeny of the Forcipulatacea (Asteroidea: Echinodermata): systematics and biogeography. Zoological Journal of the Linnean Society 162(3): 646-660
• Sladen, W.P. (1889). Report on the Asteroidea. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-1876, Zoology 30(51): xlii + 893 pages 118 plates.

Notes and References

1. Book: Barnes, Robert D. . 1982 . Invertebrate Zoology . Holt-Saunders International . Philadelphia, PA. 948. 0-03-056747-5.
2. Pazoto, C. P., Ventura, C., Duarte, M., & Silva, E. (2018). Genetic variation and population homogeneity of the sea star Coscinasterias tenuispina (Forcipulatida: ASTEROIDEA) on the coast of Rio de Janeiro, Brazil. Latin American Journal of Aquatic Research, 46(2), 355-363. doi:10.3856/vol46-issue2-fulltext-11
3. McKnight, D.G. (2006). Marine Fauna of New Zealand: Echinodermata: Asteroidea (sea-stars). 3. Orders Velatida, Spinulosida, Forcipulatida, Brisingida with addenda to Paxillosida, Valvatida. NIWA Biodiversity Memoir 120: 1-187.
4. Fau, Marine. Villier, Loïc. Comparative anatomy and phylogeny of the Forcipulatacea (Echinodermata: Asteroidea): insights from ossicle morphology. 2020. Zoological Journal of the Linnean Society. 189. 3. 921–952. 10.1093/zoolinnean/zlz127. free.