Editing Commensalism (section)

=== Octocorals and brittle stars ===

In deep-sea, benthic environments there is an associative relationship between [[Octocorallia|octocorals]] and [[brittle star]]s. Due to the currents flowing upward along seamount ridges, atop these ridges there are colonies of suspension feeding corals and sponges, and brittle stars that grip tight to them and get up off the sea floor. A specific documented commensal relationship is between the ophiuran ''Ophiocreas oedipus'' Lyman and the octocoral primnoid ''Metallogorgia melanotrichos''.{{cn|date=June 2024}}

Historically, commensalism has been recognized as the usual type of association between brittle stars and octocorals.<ref>{{cite journal | url=https://pubmed.ncbi.nlm.nih.gov/21962750/ | pmid=21962750 | doi=10.1016/B978-0-12-385529-9.00002-0 | title=Biology of deep-water octocorals | journal=Advances in Marine Biology | year=2011 | volume=60 | pages=41–122 | last1=Watling | first1=Les | last2=France | first2=Scott C. | last3=Pante | first3=Eric | last4=Simpson | first4=Anne | isbn=9780123855299 }}</ref> In this association, the ophiurans benefit directly by being elevated through facilitating their feeding by suspension, while the octocorals do not seem to benefit or be harmed by this relationship.<ref>{{cite journal | jstor=24844596 | title=Size structure of dense populations of the brittle star Ophiura sarsii (Ophiuroidea: Echinodermata) in the bathyal zone around Japan | last1=Fujita | first1=Toshihiko | last2=Ohta | first2=Suguru | journal=Marine Ecology Progress Series | year=1990 | volume=64 | issue=1/2 | pages=113–122 | doi=10.3354/meps064113 | bibcode=1990MEPS...64..113F | doi-access=free }}</ref>

Recent studies in the Gulf of Mexico have suggested that there are actually some benefits to the octocorals, such as receiving a cleaning action by the brittle star as it slowly moves around the coral.<ref>{{cite journal |doi=10.3354/meps11697 |url=https://www.int-res.com/articles/meps_oa/m549p089.pdf |access-date=24 May 2023 |title=Mutualistic symbiosis with ophiuroids limited the impact of the Deepwater Horizon oil spill on deep-sea octocorals |year=2016 |last1=Girard |first1=F. |last2=Fu |first2=B. |last3=Fisher |first3=CR |journal=Marine Ecology Progress Series |volume=549 |pages=89–98 |bibcode=2016MEPS..549...89G }}</ref> In some cases, a close relationship occurs between cohabiting species, with the interaction beginning from their juvenile stages.<ref>{{cite journal |last1=Mejía-Quintero |first1=Katherine |last2=Borrero-Pérez |first2=Giomar H. |last3=Montoya-Cadavid |first3=Erika |title=Callogorgia spp. and Their Brittle Stars: Recording Unknown Relationships in the Pacific Ocean and the Caribbean Sea |journal=Frontiers in Marine Science |date=2021 |volume=8 |doi=10.3389/fmars.2021.735039 |issn=2296-7745|doi-access=free }} [[File:CC-BY icon.svg|50px]]  Text was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/  Creative Commons Attribution 4.0 International License].</ref>