Seriously cool footage at the BBC. Also with a nice little accompanying article that you should read.
In the sequence filmed for the Life series, the invertebrates gather in a frenzy to feast on a seal carcass that has sunk to the ocean floor.
So much food may only arrive in one place once in a decade.
The nemertine worms (Parbolasia corrugatus) are able to puncture the seal’s skin with their proboscis, opening up the carcass, so that worms and marine isopods such as woodlice can enter to feed.
The starfish feed more slowly – by pushing out their stomachs through their mouths.
As a sea star pushes its stomach against the seal’s skin, it secretes digestive juices that dissolve the seal’s tissue.