Microorganisms In My New Aquarium

[macphyter]

I've got a 20 gallon aquarium that is just a few days from finishing a fishless cycle.  It was a brand new aquarium, and filter.  I used gravel from the pet store, and put in some ornaments and plastic plants also from the pet store, but there are no live plants.
 
Anyway, I've been watching it closely and lately I've noticed some tiny organisms in the water.  At first I thought I had some stray carpet fibers drifting in the water, but then I noticed one of them coil up and spin around, almost swimming.  Then it stopped spinning and continued drifting.  As I stared at the water, I noticed more and more of them.  I probably spotted about 8-10 total.  Some were on the gravel, wiggling a little bit.  Others were drifting, and would periodically spin in a coil for a few seconds. 
 
I'm not too concerned, and I suspect that once I stock it with fish, they will quickly become fish food.  Still, I have a burning curiosity to figure out what they are.  I've read all about infusoria culturing, and from what I've read the infusoria organisms are very tiny, like little specks of white dust that move around.  These fiber like organisms are bigger than that, more like a tiny fiber roughly 3 mm long, so I don't think they are the same thing.  My thought was that perhaps they are mosquito larvae, but my online searches show that mosquito larvae seem to be much bigger than this.  I'd love to get a picture of them, but they are so tiny that I doubt I could get any reasonable image with my basic digital camera.
 
Has anyone ever seen anything like this?
 

 

[DrRob]

It's fine, microorganisms come in in the tap water. It's why you've got to watch the water companies for flushing the lines with stuff occasionally to kill them off in the nooks and crannies.
 
All part of a varied ecosystem in your tank.

 

[eaglesaquarium]

Yup... might even be 'detritus' worms, which are harmless.  When they come out of their hiding spots in my tank, they quickly get eaten up by my fish.  A nice 'live meal' is good for my fish, so I don't really mind them at all.
 
 
The one thing to remember is that a fish tank is not a sterile environment.  There are lots of little critters that we will never see unless we put things under the microscope.  And, without them, you won't have a very successful tank.  Its for that reason that I say that a tank isn't matured until its reached the 6 month mark, even if its been properly cycled ahead of time.  A 'cycled' tank is not a 'mature' tank.  There's far more to it than just ammonia oxidizing bacteria.

 

[Chad]

I actually tend to say congratulations when people report copepods and other infauna in their tank. They are beneficial in a number of ways, not the least of which is a steady supply of live food for fish and fry. My scarlet badis eat nothing but micro-critters so if my tank didn't have them, they would starve. In my reef tank they are a huge part of the eco-system and feed corals, fish, and inverts like my pistol shrimp.

 

[macphyter]

Yeah, I expect them to become fish food as soon as I add some fish.  I've read all sorts of stuff about the micro-critters that grow in aquariums, and I'm not concerned about them at all.  I realize there's a huge number of different types of organisms in an aquarium, but I've never read anything about this particular type.  Like I said, its just a burning curiosity to identify this particular creature.  Maybe I should have been a microbiologist.

  In any case, I'll have fish in a few days, and they'll just get converted to fish poop in short order.

 

[Chad]

Sounds like a worm of some type but that's a challenge to identify. There are some that are parasites so it isn't always roses but I have found most are harmless to beneficial. I have a microscope I use to look at them and video them. Fun stuff.