ID on this red worm / string looking thing?

[WhiskeyCoffee]

Sometimes I see a white string coming off it. Friend or foe?

 

[Lionfish Lair]

Vermetid. I'd reach in there and crack him off and scrape him off the rock, or cover him in putty or superglue.

 

[WhiskeyCoffee]

Vermetid. I'd reach in there and crack him off and scrape him off the rock, or cover him in putty or superglue.

Do they cause more harm then good?

 

[Lionfish Lair]

That string you see, that's their net for dragging in food. It's perfectly harmless in itself, but corals to not appreciate constantly having that dragged across their surface. Their numbers can get out of hand in certain conditions when there's lots of food and it can be difficult to get rid of, once they're in there.

I've always said "live and let live" with these guys, but I've changed my mind. I've had them in my tank and be perfectly fabulous and then I have other tanks were they are a pain. Yours is the variety that's easy to deal with early on, so I would do it before he calls friends to the party.

 

[WhiskeyCoffee]

Thanks for the helpful information!

 

[Lionfish Lair]