Small white worms on glass

[Nate_Krohn]

Any idea what these guys are? Baby bristle worms?

 

[Besieged]

Hard to say for sure from the pic, but doesn't look like a baby bristle worm. Could be a detritivore, a type of nematode, or something else entirely. Any chance you can get a closer look under a microscope or at least a clearer shot under white light? Does it move with a gliding motion, or more like a wiggling, jerky movement?

 

[Nate_Krohn]

Hard to say for sure from the pic, but doesn't look like a baby bristle worm. Could be a detritivore, a type of nematode, or something else entirely. Any chance you can get a closer look under a microscope or at least a clearer shot under white light? Does it move with a gliding motion, or more like a wiggling, jerky movement?

Don’t have access to a microscope, here’s a few better pictures. More a wiggling movement

 

[Besieged]

Based on the clearer images and the wiggling movement, those look more like nematodes or possibly chaetognaths (arrow worms) rather than baby bristle worms. Bristle worms, even when small, tend to have visible segmentation and setae (tiny bristles), which I’m not seeing in these shots.

Nematodes are common in reef tanks, especially in the substrate, and are mostly harmless detritivores. If they’re free-swimming, they could be feeding on microfilm or biofilm. If you see them in large numbers, it could indicate excess nutrients, but otherwise, they’re just part of the microfauna.

A second possibility is chaetognaths, which are small predatory planktonic worms that sometimes appear in tanks with a lot of copepods. They move in a distinctive darting or wiggling fashion and are usually harmless unless their population explodes.

If you want to narrow it down further, you could try observing them under different lighting or with a magnifying glass. If they’re nematodes, they’ll have more of a simple, featureless body. If they have small eyespots or a distinct head, they might be something else entirely. Either way, they’re probably not harmful, just a sign of a healthy tank ecosystem.

 

[I never finish anythi]

Based on the clearer images and the wiggling movement, those look more like nematodes or possibly chaetognaths (arrow worms) rather than baby bristle worms. Bristle worms, even when small, tend to have visible segmentation and setae (tiny bristles), which I’m not seeing in these shots.

Nematodes are common in reef tanks, especially in the substrate, and are mostly harmless detritivores. If they’re free-swimming, they could be feeding on microfilm or biofilm. If you see them in large numbers, it could indicate excess nutrients, but otherwise, they’re just part of the microfauna.

A second possibility is chaetognaths, which are small predatory planktonic worms that sometimes appear in tanks with a lot of copepods. They move in a distinctive darting or wiggling fashion and are usually harmless unless their population explodes.

If you want to narrow it down further, you could try observing them under different lighting or with a magnifying glass. If they’re nematodes, they’ll have more of a simple, featureless body. If they have small eyespots or a distinct head, they might be something else entirely. Either way, they’re probably not harmful, just a sign of a healthy tank ecosystem.

Very informative information. Thank you.

 

[BriDroid]

I have noticed them popping up in my tank over the last few days. I was infested with red flatworms, and I’m wondering if the flatworms weren’t eating these guys? I’ve been sucking them out with a Pipette, but I guess I’ll leave them be for now. I’ve also noticed my copepods have started to rebound without the flatworms too!

Horrible video of the worm