So holothurians or sea cucumbers, they typically don't move much. You can see. He's pretty happy there.
And what we see the holothurian doing here again is consuming sediment.
They have some really elaborate defense mechanisms.
So, they are able to eviscerate their guts,for example, and that will then stick to the predator and confuse them.
They can also swim over short distances to get away from things.