Editing Sea cucumber (section)

=== Locomotion ===
Some abyssal species in the abyssal order [[Elasipodida]] have evolved to a "benthopelagic" behaviour: their body is nearly the same density as the water around them, so they can make long jumps (up to {{convert|1000|m|disp=or}} high), before falling slowly back to the ocean floor. Most of them have specific swimming appendages, such as some kind of umbrella (like ''[[Enypniastes]]''), or a long lobe on top of the body (''[[Psychropotes]]''). Only one species is known as a true completely [[pelagic]] species, that never comes close to the bottom: ''[[Pelagothuria natatrix]]''.<ref>{{cite web|url=http://echinoblog.blogspot.com/2012/09/deep-sea-swimming-sea-cucumbers-and.html|title=Deep-Sea Swimming Sea Cucumbers and the "most bizarre holothurian species in existence" ! |last1=Mah |first1=Christopher L.|date=2012-09-18 |website=The Echinoblog }}</ref>