These large nudibranchs are carnivorous and have a great way of feeding.
They throw their ‘head’, an oval veil, in front of them, and using hairs around the edge, attempt to scoop up whatever they can find, usually small Crustacea.
You can watch this Melibe moving around, searching for food. About 2/3 of the way through you can see the Melibe captures a small shrimp in it’s mouth and then holds it shut until the shrimp is, presumably, devoured!!