Skin growing on rocks

[Nic a Jon]

Hi fellow reefers,

Recently discovered a thin, translucent skin-like stuff appearing on my LR. And it has a thin layer of sand stuck on it.

On the underside on one of the LR I also have some gluely and sphagetti-like looking stuff growing and joining up to another piece of LR. Are these some sort of worms or worms created stuff?

Also noticed a 3 inch worm (with tentacles near the mouth) in the sandbed near these 2 pieces of LR. Could it be the cause of the skin like stuff on the LR. Please advise if they are harmful

Sorry no DC to take pictures.

[Cookiemunster]

Those are the mucas slime from the spaghetti worm. They use the slimy mucas to trap detritus and food. They are harmless and are part of the eco system....ie Important. The tentacles are its feeding tubes. The worm itself is much bigger.

You can read more about them here. Worms

[Nic a Jon]

Thanks very much Cookie, by the way I caught a 7 inch worm yesterday in one of the LR. Looks very much like a earth worm.

[Nautical]

Nic a Jon, so what did you do with the 7 inch worm ? Did you put it back into the tank or terminate its life or whatever ?

Cookiemunster, is this worm best left alone or should be removed ?

[Cookiemunster]

no prob.

most likely the worm is a bristle worm. They can grow up to 4ft in length in very established tanks of large volume.

They are part of the sand shifters and help to stir the sand and feed on ditritus and other organic foods. So its ok to put them back.

However, if its reddish brown in colour, try to throw them away. As these are known as fire worms and they pack with poisonous bristle needles and feed on corals. They also reproduce very very fast. Never touch worms with your bare hands if possible. The hairy spikes (bristles) can have a very painful burning effect and is extremely irritating.

Many times when we handle live rocks and get a sudden prickly feeling in the fingers which doesn't go away and you can't see anything in the fingers....this is the result of being stung by the bristles.

But dun panic and start stirring everything up. You only need to worry about the really big ones. 3 to 4 inch size fireworms. The rest are beneficial to your aquarium in general.

Read here for more info about worms of this family.

Bristleworms FAQ

Yours,

Wormmunster

[ervine]

I believe both bristleworms and fireworms are redish brown what... no meh? and both of them have spikes on their backs...

So how to differentiate the two

[Cookiemunster]

the dreaded fireworm

[Cookiemunster]

The cause of the skin on rocks. Spaghetti worms.

[Nautical]

Cookie/Wormmunster - you is the can lah, when you mentioned "Many times when we handle live rocks and get a sudden prickly feeling in the fingers which doesn't go away and you can't see anything in the fingers....this is the result of being stung by the bristles." Now I know it is this SOB who is giving me much grief. Thanks for the revelation.

[Cookiemunster]

It just occured to me that not only worms can produce the mucus skin like effect on your rocks. There is also a family of invertibrates closely related to snails but looks like a worm. Its known as Vermetid snails.

They feed by creating a mucus bag which traps phyto and detritus.

Photos and more info can be found here: Vermitid snails