In Reply to: Worm ID help needed posted by Elaine on September 23, 2007 at 11:38:06:

They're both epitokes, sexually mature polychaetes. Non-reproductive worms are known as atokes. Many polychaete species transform parts of their bodies as they become reproductive in order to swim up in the water column and spawn. Some turn into sacs of skin holding eggs or sperm & the animal will die. Others are less modified & after spawning will swim back down to the bottom. Your first picture is of a nereid in which the first 1/3 is fairly normal but the segments in the rest of the body are modified. I'm not sure what family the second one belongs to because I can't see enough details. This one is not very modified at all. It's a female - the orange color comes from the eggs.