Sea Cucumbers

Echinoderms

ZeFrank

Beautiful sea cucumber swimming 1 min starts 25 sec

Enypniastes eximia video below

A swimming sea cucumber, Enypniastes eximia, was observed during NOAA’s expedition in the Gulf of Mexico, on 13 December 2017. The sea cucumber spends most of its time feeding off of surface sediments on the seafloor, but can swim if it wants to get somewhere more quickly or evade a predator. Common names for these holothurians include: “swimming sea cucumber”, “Spanish dancer” and “headless chicken monster”. Credit: Video courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico, 13 December 2017

Defense system

Wikianimals, nice gallery at the end

https://wikianimals.eu/animals/sea-cucumber

Gallery of sea cucumbers, Joel Sartore:

https://www.joelsartore.com/keyword/sea-cucumber/

Larval form