What the heck is in my tank?

[Llewellyn]

Hi,

I was doing some tank maintenance and noticed these very tiny little white specks in the sump area. At first I thought it was just some kind of debris, but then I realized they were swimming. They're really quick too. I'm new at all this, so I don't know what they are, if they're good or bad or what. When I say tiny, I mean smaller than the head of a pin but still visible to the naked eye. My water quality is stable at ammonia 0, nitrites 0, nitrates 0, pH 8.4, salinity 1.24. Thanks!

Kim

[Ninong]

That's not enough information to make a call. They might be okay but we really can't say based on your description.

[Llewellyn]

It's a 40 gal acrylic that just went through a move and mini-cycle about a month ago. The only thing currently in it are three good-sized Capnella leathers. At the advice of some here, I've been letting it settle a bit from its mini-cycle before adding anything else, but was getting ready to stock a clean up crew and add some more live rock this weekend. I have seen a couple of small worms in some crevices (red with a black vertical stripe) I don't really know anything about the tank before I received it, but it seemed well maintained and in good order when I picked it up. Let me know what other info would help identify these little critters.

Thanks!

Kim

[Ninong]

I'm sorry, that's not what I meant by "information." What I meant was that "tiny little white specks that swim fast" could be lots of things.

I'm not faulting you for not being able to be more specific, I'm just saying that it's hard to say what you have based on that description.

Sorry for the confusion.

[cdearing]

Hi Kim,

I posted a thread called Sand Fleas? when I first started my tank because I had little white specks crawling around on the glass, mainly near the sand. I was told not to worry and that they were probably some sort of pod. I don't see them anymore, only the bigger pods out scurrying around in the LR at night. If I had to guess, I'd say that it's not a worry and probably some sort of pod. I think as long as you don't see these little white specks on your fish or corals then they aren't a parasite and not to worry.

Cyn

[Bigred0942]

Could they be copepods??? If they are they are not a bad thing, unless you have too many.

[Ninong]

...when I first started my tank because I had little white specks crawling around on the glass, mainly near the sand.

That's not at all the same as "tiny little white specks that swim fast."

[Ninong]

Could they be copepods???

If you put a couple of drops of seawater under a microscope, you may very well see a dozen different species of copepods, all too small to see with the naked eye. Most of the copepods that we think of in our tanks are the larger ones that look like tiny sand fleas scurrying over the sand bed and live rock at night when we turn a flashlight on the tank. The description of "tiny little white white specks that swim fast" doesn't match any copepods that I can think of -- the "white" part in particular, the fact that they appear "white" as opposed to either colorless or some dark shade.

Obviously isopods are often white but the really nasty ones wouldn't be described as "tiny white specks."

[cdearing]

Kim,

Check out this for an interesting read on copepods and/or amphipods

Those Little White Bugs In Your Saltwater Aquarium Profiled - Classification Information and Facts About Copepods and Amphipods

It says this: " It is not unusual at one time or another when keeping a saltwater aquarium to find tiny microscopic-like white bugs swimming or crawling all over your tank. What you are most likely seeing are Copepods and/or Amphipods. These are shrimp-like crustaceans that dwell in the substrate as adults, but during their larval and juvenile stages are most often free swimming. "

So when Ninong says "That's not at all the same as "tiny little white specks that swim fast", this article seems to disagree. They just might be the same, depending on what stage the pod is in as to whether it is crawling or swimming.

Cyn

[Llewellyn]

Thanks for the info. . .here are a couple pics. I'll try to get better ones tomorrow.

[metalhead]

Kim,

Check out this for an interesting read on copepods and/or amphipods

Those Little White Bugs In Your Saltwater Aquarium Profiled - Classification Information and Facts About Copepods and Amphipods

It says this: " It is not unusual at one time or another when keeping a saltwater aquarium to find tiny microscopic-like white bugs swimming or crawling all over your tank. What you are most likely seeing are Copepods and/or Amphipods. These are shrimp-like crustaceans that dwell in the substrate as adults, but during their larval and juvenile stages are most often free swimming. "

So when Ninong says "That's not at all the same as "tiny little white specks that swim fast", this article seems to disagree. They just might be the same, depending on what stage the pod is in as to whether it is crawling or swimming.

Cyn

I think Ninong was trying to point out that little white critters aren't always copepods, hence his reference to isopods. Some isopods can be very bad and almost impossible to remedy but I think there are some biological methods of control available. I'm not sure how to tell bad isopods from good ones if there is such a thing as good isopods.

I'm not experienced enough to make a judgement based on the pictures but I think it would be unusual for that many copepods to be out on the glass while the lights are on.

Kim, are these spread over all the glass in your tank or just isolated to one area? When you say that they swim fast do you mean that they scurry across the glass quickly or that they swim around in the water?

[Llewellyn]

I don't see them anywhere but in the sump so far, they are not on the glass. They dart through the water very quickly. They're so small (the pic is very close up), I'm not sure I could see them in the tank itself without the black background. They'd also be hard to see because of the current going in the tank. I've looked very closely and they're definitely not on the glass, though, at least not yet!

Kim

[Ninong]

Thanks for the info. . .here are a couple pics. I'll try to get better ones tomorrow.

You're showing a lot more detail in that second photo. That's a lot better than "tiny white specks that swim fast." Now we're getting somewhere. We still may not be able to ID anything unless you owned a microscope and could stick a couple of them under the microscope.

What we're going to have to go on with something like this is your verbal description of what they look like (in detail) and their behavior.

Just to recap, they swim fast in the water column. They are not crawling around on the glass or the substrate, they are "swimming fast."

[Seige]

I have what I believe are copepods darting around just above the surface of my main tank water. Not the same behaviour but it could be something similar. Mine look like this Google Image Result for http://www.educnet.education.fr/localisation/pedago/argos03-04/images/copepod2.jpg