I was checking out my dad's saltwater tank and found that the one little worm-thing I found around Christmas has turned into many, which I think are bearded fireworms (hermodice carunculata). I'm really not sure though. The largest ones I've seen are about an inch long. I've read that some worms are bad and some are good. I figure these little guys aren't any harm at the moment, but I'm a little worried they could kill an anemone or fish once they get larger. Not to mention that I also read that they can have some of their spines floating around in the water that can stick in you or a fish even if you don't bother them.
Here's a I took of two of them. My camera isn't very good at taking pictures of very small things. The pink part of the larger one is about the same color that they actually are, and the dark parts on them are organs and/or food inside them. They're clearish, like baby earthworms. The white leg-things are furry, not solid, which is why I figure they're bearded fireworms.
But I've only been able to match up pictures I find on the internet, and it seems they come in a variety of colors. I haven't found enough information to really know if they're a threat or not.
There are hermit crabs, snails, various anemone-things, two fish, copepods (if that's what they're called), and two (at least, it had babies) starfish. There's no living coral, but there used to be featherdusters popping up everywhere. Could they be to blame for the featherduster's sudden disappearance? Do you think they would harm anything in the tank? Should we kill them or leave them alone? Are they really bearded fireworms?