Centipede looking things in live rock

[Saltwtrnewbie]

Hi guys! Just picked up a poorly cared for tank from someone to bring it home and try to save it and the fish. The live rock had numerous (over 50) centipede looking things all over and inside, just wondering what they are. New to saltwater tanks. Pics enclosed. Thank you!

 

[T-J]

Bristle worms. Part of the CUC.

 

[Cell]

Removal is optional. You will get differing opinions. I remove them. They are ugly, can get big, and can sting.

 

[MtnDewMan]

Bristleworm. I'd keep them, good at eating stuff in the rock and sand.

 

[Tired]

Those are bristleworms. Extremely common, and useful detritivores. Don't touch the rock with your bare hands, as they can sting you with their bristles. Also, the rock may have sharp edges and/or nasty bacteria, so you shouldn't be touching it anyway. Gloves are your friend.

 

[vetteguy53081]

Not welcomed in my tanks but harmless unless you touch them. They eat detritus and uneaten food making them beneficial but can get to an easy 12" if they have steady food supply

 

[Rovert]

Agreed, they're bristle worms. Think of 'em as dental floss for live rock.

 

[Lost in the Sauce]

Arrow crabs are a great way to keep the population in check.

 

[Tired]

Arrow crabs are also a great way to keep your small fish population in check. Best to be careful with those critters.

 

[Saltwtrnewbie]

Thank you everyone!!!!!