Editing Coral reef (section)

===Invertebrates===
Sea urchins, ''[[Dotidae]]'' and [[Nudibranch|sea slugs]] eat seaweed. Some species of sea urchins, such as ''[[Diadema antillarum]]'', can play a pivotal part in preventing algae from overrunning reefs.<ref>{{cite book
 | last = Osborne | first = Patrick L. |url={{google books |plainurl=y |id=EwPwPHDM-YsC}}| title = Tropical Ecosystem and Ecological Concepts  | publisher = Cambridge University Press | year = 2000 | location = Cambridge | page = 464 | isbn = 978-0-521-64523-2}}</ref> Researchers are investigating the use of native collector urchins, ''[[Collector urchin|Tripneustes gratilla]]'', for their potential as biocontrol agents to mitigate the spread of invasive algae species on coral reefs.<ref name="Westbrook-2015">{{Cite journal|last1=Westbrook|first1=Charley E.|last2=Ringang|first2=Rory R.|last3=Cantero|first3=Sean Michael A.|last4=Toonen|first4=Robert J.|last5=Team|first5=HDAR & TNC Urchin|date=2015-09-15|title=Survivorship and feeding preferences among size classes of outplanted sea urchins, Tripneustes gratilla, and possible use as biocontrol for invasive alien algae|journal=PeerJ|language=en|volume=3|pages=e1235|doi=10.7717/peerj.1235|pmid=26401450|pmc=4579015|issn=2167-8359 |doi-access=free }}</ref><ref>{{Cite journal|last1=Conklin|first1=Eric J.|last2=Smith|first2=Jennifer E.|date=2005-11-01|title=Abundance and Spread of the Invasive Red Algae, Kappaphycus spp., in Kane'ohe Bay, Hawai'i and an Experimental Assessment of Management Options|journal=Biological Invasions|language=en|volume=7|issue=6|pages=1029–1039|doi=10.1007/s10530-004-3125-x|bibcode=2005BiInv...7.1029C |s2cid=33874352|issn=1387-3547}}</ref> ''[[Nudibranchia]]'' and [[sea anemone]]s eat sponges.

A number of invertebrates, collectively called "cryptofauna", inhabit the coral skeletal substrate itself, either boring into the skeletons (through the process of [[bioerosion]]) or living in pre-existing voids and crevices. Animals boring into the rock include sponges, [[bivalve]] mollusks, and [[sipuncula]]ns. Those settling on the reef include many other species, particularly crustaceans and [[polychaete]] worms.<ref name="Nybakken" />