Bristle Worm?

Question

I came home this afternoon and saw THIS in my tank.
http://i45.photobucket.com/albums/f94/puredoller/100_1614.jpg
http://i45.photobucket.com/albums/f94/puredoller/100_1621.jpg
I know the photos aren't great but yeah. I looked it up and decided it must be a bristle worm which sound scary! But it's so big I can't imagine they aren't MORE... plese tell me it's possible this was the only one.

But furthmore. I took the rock out and put it on the kitchen counter for removal of the worm.... when I saw millions of THESE (the long thing all the way to the right)
http://i45.photobucket.com/albums/f94/puredoller/100_1626.jpg

now I realize you can barely see this but we initially thought they were tiny worms until we saw one swimming in the bowl. my boyfriend said they looked like tiny shrimp and was wondering if Troy (our peppermint shimp) had reproduced alone... then I said HEY! That could be an amphipod!

Aren't they tiny shrimp like looking things?

J dog: I got the tank 3 weeks ago in a state of MAJOR disrepair. I can't complain, I got like $1500 worth of stuff for $250 but I've spent about 20 hours cleaning it all. I got rid of all his substrate and put my own in the tank from my 55 gallon I was upgrading from. I had a VERY clean tank. I can only assume that the bristleworm was hiding out in his liverock (about 80 pounds worth).

no. there is no undergravel filter.

Answer 1

The first is a bristle worm. Despite the nasty sounding name, most of these are harmless sand sifters and detritovores that do more good for your tank than harm (unless you touch them, that is - they have a rather painful sting/burn if you touch the spines). A few species are harmful, but these are more typically called fireworms, and don't have the pale coloration of the one you've got. At one time, all bristleworms were thought to be bad, especially when they were seem munching on polyps or clams, but it's been confirmed that these only eat tissue that's already dead or dying - they aren't what's responsible for the deaths.

Stiil, lots of people don't care to have them in the tanks. You can make or buy a bristleworm trap to get some of the larger ones out, or get a dottyback, wrasse (something in the Halichoeres family), or coral banded shrimp which are natural predators of the small ones (and depending on what you already have in the tank).

It's difficult to see the last photo clearly, but I believe you do have an amphipod, typically called a gammarid or gammaridean shrimp (there are also freshwater species of these): http://reefkeeping.com/issues/2004-09/rs/index.php

Answer 2

Bristle worms are harmless to your aquarium.
DO NOT TRY TO KILL THEM!!!!!!

They are there because there is food for them to eat. If you somehow killed them all (which you could only do with a bomb), then the stuff they are eating would either quickly decay and foul the water or the stuff would slowly decay and cause an algae bloom.

Aquariums are a holistic type of thing. Don't look at things in it, look at the total system. Bristle worms are a sign that there may be too much waste/organic matter in the tank. You will always have a some in the tank. This is good.

The little swimming things (copepods) are good too, for the most part. Some things you find are pests, but when you try to kill some of these pests you end up getting more good animals killed than the bad.

One thing to watch out for, Bristle worms sting. They shouldn't bother the fish, but they may get you when you clean the tank. Tape is good at pulling out the bristles, and hot water speeds up the break down of the venom.

To finish, clean tanks have small populations of Bristle worms. Dirty substrate is what the love. If you have an under gravel filter, then it is probably making the substrate dirtier.

Answer 3

Yes it is a bristle worm. Don't worry about taking it out because they are good scavengers. You probably do have more in your tank. For the second thing, if it is a small, shrimp type thing then it is probably an amphipod or mysis shrimp.

You are going to get all kinds of worms and other invertabretes coming out of your liverock. That's part of the fun. 99.9% of time it is something that is harmless so don't worry and enjoy it.