Help with ID on Black swirl

[604reefer]

I'm not sure what this is... it's been growing slowly on the mushroom rock. There are also 3 of these on my frogspawn, but 2 look clear - the same color as the frogspawn skeleton, the other is black. I think there's also one on my hammer plug base, but I'd have to turn it to get a good look. Tank is 4 months old.

Any ideas? Googling "black swirl on coral" and variations haven't yielded me much. I took a look through http://www.lionfishlair.com/hitchhikers-guide/ and it could be a "peanut worm" or "vermetid snail" but I don't know why 2 are clear and one is black on the frogspawn? Thoughts?

http://i6.photobucket.com/albums/y210/stockboy88/IMG_1052.png

http://i6.photobucket.com/albums/y210/stockboy88/IMG_1054.jpg

[GoFish]

Vermetid snail :thumb:
Not a fan, they irritate corals. Usually I scrape them off from the bottom if accessible, the shells are quite hard and hide into the swirl if you touch them

[Myka]

I agree that both examples are vermetid worms.

[604reefer]

Thanks!

I sniped 4 of these with a razor blade and hacked the base away. 3 off my frogspawn and one off a hammer. Hopefully the frogspawn perks up again...

Still got 2 on the mushroom rock, but that's where my jumper hides and I think he needs some space lol.

[smokinreefer]

Yeah if you can get rid of them I would.

Even in "plague" porportions I find them to be more of an eyesore than anything.

Though they can irrate some corals when they send out their sweepers.

They don't really have any benefits of being in the tank.