• Rebecca

Eric8832

I also have a couple of smooth brown worms, they stay in one place and haven't been noticed for being bad.

Joyce

This may be one of the many species of Phascolion – a fairly diverse genus of about 40 species of small worms, as a rule. But it could also be Sipuncula; the photo does not clearly show the entire worm. Don't worry, these worms play an important role in reef ecosystems (population control is desirable). They typically feed on algae, small animals, and their remains. Here, take a look at this link: