When (Sea) Pigs Fly

Diving at Wetmore Seamount, inside the Johnston Atoll Unit of the Pacific Remote Islands Marine National Monument, the team glimpsed this great view of a flying sea pig. Sea pigs are the general common name for multiple genera of cucumbers with a small number of very pronounced tube feed along the side of their bodies, resembling legs. This translucent animal identified as either an Amperima sp or Peniagone sp. is one of the smaller sea cucumbers encountered on this expedition with a maximum size smaller than a banana. Getting a further ID on this individual would have required collection to look at the ossicles - tiny calcified skeleton parts within the skin - under a microscope in a laboratory.

This unique winding swimming style uses the dorsal fan-shaped frill to lift the cucumber off the seafloor, resembling a flapping cape. This predation response can help sea cucumbers take off to safety, and is also a method to rise up into the current to travel long distances efficiently in search of find new feeding areas. If you look closely you can see a ring of feeding pads, modified mouth parts, which help sea cucumbers sort through sediment grains and sunken marine snow in search of freshly fallen morsels of detritus across the seafloor. Through the clear body wall, a full stomach and gastrointestinal tract are visible showing dinner is served for detritivores consuming food falling from the productive surface waters far above.

Learn more about this expedition funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.