While walking along the float the other day, I saw one of these horrors. It was about two feet long, floating and gimping slowly thru the water with its dozens of paddle-arms, and was emitting green goo. It was not photogenic.
I quote this ghoulish horror-screed of nasty science facts:
Worms are also very good at repairing parts of their bodies. Should they lose only their head to a hungry fish, they can regenerate it, but it will take a while to grow as large as the one they lost.
Bristle worms have separate sexes, but you generally can't see the differences unless they are ready to reproduce. Eggs and sperm are produced in the worm's back section. When ripe they can be released in different ways, depending on the species. In most species, the body wall simply opens up and the eggs or sperm come flooding out, to be fertilised in the water.
In some families of worms that live in the tropics, the segments containing the eggs and sperm break off from the rest of the worm and float up in the water, where they are released. Sometimes this is proceeded by the adult worm swimming up into the water.
This spawning takes place during particular combinations of tide, phase of the moon and water temperature, which reef-dwelling people can predict. They scoop up the segments containing eggs and sperm and eat them! Fertilised eggs change quickly into swimming, top-shaped larvae which become part of the planktonic community. After they have grown to look more like a worm and have about nine segments they settle out of the water and look for a suitable place to live.
I think that "suitable place to live" should consist of "banished to the center of the sun".