Editing Sea cucumber (section)

=== Symbiosis and commensalism ===
[[File:Periclimenes imperator (Emperor shrimp) on Bohadschia argus (Sea cucumber).jpg|thumb|right|Emperor shrimp ''[[Periclimenes imperator]]'' on a ''[[Bohadschia ocellata]]'' sea cucumber]]
Numerous small animals can live in [[symbiosis]] or [[commensalism]] with sea cucumbers, as well as some parasites.

Some cleaner shrimps can live on the tegument of holothuroids, in particular several species of the genus ''[[Periclimenes]]'' (genus which is specialized in echinoderms), in particular ''[[Periclimenes imperator]]''.<ref name="Mah Crabs & Shrimps">{{cite web|url=http://echinoblog.blogspot.fr/2013/10/crabs-that-live-in-sea-cucumber-anuses.html|title=Crabs & Shrimps that Live in Sea Cucumber Anuses |last1=Mah|first1=Christopher L. |date=1 October 2013|website=The Echinoblog }}.</ref>
A variety of fish, most commonly [[pearl fish]], have evolved a [[commensalism|commensalistic]] symbiotic relationship with sea cucumbers in which the pearl fish will live in sea cucumber's cloaca using it for protection from predation, a source of food (the nutrients passing in and out of the anus from the water), and to develop into their adult stage of life. Many [[polychaete]] worms (family [[Polynoidae]]<ref name="Mah Worms & Snails">{{cite web|url=http://echinoblog.blogspot.fr/2014/01/worms-snails-that-live-onin-sea.html|title=Worms & Snails that Live On/In Sea Cucumbers!  |last1=Mah|first1=Christopher L. |date=22 January 2014|website=The Echinoblog }}</ref>) and [[crab]]s (like ''[[Lissocarcinus orbicularis]]'') have also specialized to use the mouth or the cloacal respiratory trees for protection by living inside the sea cucumber.<ref>{{cite journal| journal=Advanced Aquarist's Online Magazine|volume=2|issue=3| url =http://www.advancedaquarist.com/issues/mar2003/invert.htm | title =Aquarium Invertebrates | first = Rob, Ph.D.| last = Toonen | access-date =2007-10-03 |date=March 2003}}</ref> Nevertheless, holothuroids species of the genus ''[[Actinopyga]]'' have anal teeth that prevent visitors from penetrating their anus.<ref name="Mah Pearlfish-Sea Cucumber">{{cite web|url=http://echinoblog.blogspot.fr/2010/05/when-fish-live-in-your-cloaca-how-anal.html|title=When Fish Live in your Cloaca & How Anal Teeth are Important: The Pearlfish-Sea Cucumber Relationship |last1=Mah|first1=Christopher |date=11 May 2010 |website=The Echinoblog }}</ref>

Sea cucumbers can also shelter bivalves as endocommensals, such as ''[[Entovalva]] sp''.<ref name="Mah CLAMS that live in their throat">{{cite web|url=http://echinoblog.blogspot.fr/2010/08/sea-cucumbers-got-fish-that-live-in.html|title=Sea cucumbers got fish that live in their anus and CLAMS that live in their throat! (but not at the same time) |last1=Mah |first1=Christopher L. |date=31 January 2010|website=The Echinoblog }}</ref>

<gallery style="text-align:center;" mode="packed">
Image:Swimming Crab - Lissocarcinus Orbicularis on Sea Cucumber.jpg|''[[Lissocarcinus orbicularis]]'', a symbiotic crab.
Image:Shrimp on Sea Cucumber.jpg|''[[Periclimenes imperator]]'', a symbiotic shrimp.
Image:Polychètes sur T. anax.JPG|[[Polynoidae|Polynoid]] worms on a king sea cucumber.
</gallery>