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Live Rock Questions!!!


Colossal Squid
Staff member
Moderator (Staff)
Nov 20, 2002
Colin I have another question. :smile:

This live rock that keeps being discussed. Is it the rock that has all these creatures living in it? Ya know, featherdusters, corals and such? I have never had a tank started with this. Most of my tanks are started with major culture from an existing tank, I already have had.

Now Hermins tank is about 3 years old now. I have quite a population of little red feathery like worms that always come out and finish off his meal remains. (my daughtor was freaking over them!) What are these? They look almost like miniture sand worms. Is this considered part of what live rock could be made up of? If so, then my whole sand bottom must be full of them.

I may be mistaken, but I think those are bristleworms...the generic term for a number of different free-swimming and burrowing polychaete worms (same general animals as sessile feather-dusters.) Yes, live rock may contain these...live rock is basically lumps of (ideally) dead reef or even volcanic rock that has collected from around coral reefs (and ideally thus is not damaging to be removed as it's not part of the reef.) It's great stuff because it's loaded with so many different invertebrates, algae, and bacteria that it really helps get a tank going and keep it stable. I like it just because it looks cool stacked up in the tank, with tons of things growing on it and tons of little critters all over it...feather-dusters, sponges, terebellid worms, you name it. Many tanks get bristleworms as hitchikers on their live rock. Some people even get octos as hitchikers!

I know these bristleworms are considered nuisance critters, but I never read enough to find out why. I know one reason could be that many species of these are known as "fireworms" because their feathery bristles are incredibly sharp and brittle...they will pierce your skin, break off, and remain imbedded, causing firey irritation for a long time. :goofysca:

Bristleworms are your friend! Embrace them LOL! Well, not literally but they do so much good work for us with our messy cephs!
Yeah, they can give you an itch, not always as bad as a fireworm but they do jag you with bristles if you pick them up.

i have one nicknamed 'Big Jim' (for no particular reason), but Big Jim is about a foot long and lives in the octo tank, he can swallow a whole mussell in one go! and cleans up well after octopuses.

On that note, my sub adult bimac has been rehomed so i can get in 4 baby bimacs and grow them up to hope for a pair! :smile:

I thought they were my friends!!!!!!! :yuck: Actually my daughtor's more upset than I am. 5yr. olds love octopus's but hate worms!!! Don't figure!!!

Anyway, question, you mention you are getting baby bimacs! You can raise them together, in one tank???? Could I add another to Hermins tank??? Or is that asking for trouble???


I havnt had the chance to keep bimacs together for very long. The last pair I bought were together for only a few days because one of them was worse for wear when it arrived.

bimacs are often kept togther in batch cultures but I would imagine that they need to be reared that way from young. Adding another bimac may cause problems unless you can sex your octopus and are adding another that you are sure is the opposite sex. However, that's just theory. I will be able to tell you better in a month or so. I will have them in quite a large tank for their size too..... they are only about th esize of a grape and the tank is a 60gal totally full of rocks and pipes and a whole load of other stuff for hiding.


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