Sea cucumbers (Holothurians) are a type of Echinoderm and are related to sea stars and sea urchins. They generally have a caterpillar-like appearance, often with the addition of some tentacles around the mouth, but some have more adventurous body-shapes, including the famous sea pig (hilarious video here https://www.youtube.com/watch?v=_y4DbZivHCY) and sedentary varieties like Psolus squamatus, which we see often in the deep sea attached to rocks, filtering plankton from the water, and not looking like a Holothurian at all! Some species are a delicacy in various parts of the world (have you tried trepang, bêche-de-mer, or balate?).
This particular sea cumber, who we so elegantly hoovered up on Anton Dohrn Seamount, is called Parastichopus tremulus. It is a very common species in the North East Atlantic and can be seen often in our ROV footage shuffling along on its tube feet, eating organic detritus from the sea floor. This makes them pretty important in the nutrient cycle in the deep sea as part of the greater environmental waste processing system. They are one of our sample species and we hope to learn a lot more about how inter-related the North East Atlantic population is.
Text by Rebecca Ross, Plymouth University