What. In the heck. Are these!?

[cpuphantom]

Hi fellow aquarium hobbyists. I'm new here... I've kept tanks forever, but just never had a need to ask a question until now. It just always seemed someone had already asked it.

I have a tank, non-planted 15 gallon freshwater that's been running for about 2 years. I just have a betta.

The water parameters have been fine... but I've always had just a bit of brown algae, diatoms, growing on the power filter, leaves where I didn't care to scrub it. It didn't bother me and didn't spread.

Tonight, I got home from work... flipped the (usually timed) lights on to see my fish and I saw this:

That is the pump casing of the filter, that usually had a generous covering of diatoms on it. At first I was like, sweet... the diatoms are dying back. Then I realized those lighter colored dots were moving.

Seriously... here's a video:

I have never heard of bugs... mites... whatever in a fresh water tank. A google search turned up nothing. Any ideas what the heck those are... if they are dangerous to my fish, and how to get rid of them?

Thanks!

 

[Chenpoes]

Wow, I've never seen anything like that. If I saw them on my filter I'd be tempted to throw the whole thing out, hate tiny moving clusters lol. Maybe some type of copepod? (I don't think many species are harmful btw) Although I don't know where they'd come from- I'll link a video of some below. If not, maybe some type of bug got in and thats its larval stage?

 

[cpuphantom]

Thanks Chenpoes. I had actually never heard of copepods before yesterday... but I think you are right.

Edit: and I guess my google search originally failed me because I was searching for "bugs" or "mites." Not tiny crustaceans. lol. Because now that I know what I'm searching for, I see info everywhere.

 

[cpuphantom]

OMG. Update. When the lights came on this morning I checked in and they had cleared the diatoms entirely. wow.

So now I'm wondering... I had previously had two ember tetras in the tank too. I had moved them a week ago to new planted tank I started a few weeks previously. These fish never seemed to eat, so I rarely fed them... and they thrived anyway... I'm wondering if they were keeping this copepod population under control for me... and I never knew.

 

[mrsP]

Most likely they did, and that's brilliant diet for your fish.

 

[Chenpoes]

Would you look at that, a free food source and diatom eater! I also hadn't heard of them before I saw this post, but I go so curious about what the little wiggly dudes were that I had to do a deep dive lol

 

[Redshark1]

That's really cool!

 

[MomeWrath]

Seed shrimp, maybe? They look a little bit too big for FW copepods. Either way, I would consider them beneficial, and your betta will probably enjoy hunting them too. If you decide they have to go, kindly bag them up and send them my way lol.

 

[AmnScott]

I have never seen that before to be honest. But I am sure many of my fish wish they had free snacks like that in their tanks.

 

[cpuphantom]

I think Magicpenny is right that they are seed shrimp. I gotta admit, the little guys are growing on me. That tank hasn't looked that pristine since I started it.

I think I will actually try and catch some to stock my new tank.