thin white worm

[jonstfrancis]

I've noticed these worms in small numbers in my tanks on and off over the years. I saw one today in my tank swimming aimlessly in the flow until a minnow swallowed it. What are they?

Some posts online say these are planaria and are evidence of a dirty tank. But they don't look anything like any planaria I've seen in the pond. They are perhaps a centimetre long and very slender, I think pointed at both ends, white, no noticeable segments or organs, nondescript. They seem to dwell in the gravel (in the past I hoovered up some when cleaning the substrate, although I've not noticed any in this set-up) and become disturbed by fish where they wriggle in the open water and are then eaten quickly.

My tank is clean, at least I think so.

regards,
Jon

[ClownLoachSharky]

do you have kuhli loaches?

[jonstfrancis]

do you have kuhli loaches?

Hello,
No I don't have them, and I probably should have said that my tank isn't heated/tropical.
regards

[ClownLoachSharky]

hmm have you fed any worms to them. It might even be parasites.

[jonstfrancis]

hmm have you fed any worms to them. It might even be parasites.

I haven't fed them worms, although in the warmer months I net insect larvae (gnat/mosquito etc) from pots of water outside. These winter months I feed a mix of dried stuffs.

The reason I don't think they are parasitic is because I've never seen them on the fish or being defecated. I associate them with the substrate (gravels). But where they come from is a mystery. Having said that, they do look like a nematode of some sort.

regards

[ClownLoachSharky]

hmm, ive seen these white long worms in a hole in the yard just below some larvae. That might be it. you may have scooped some wroms when you got the larvae

[jonstfrancis]

Yeah, I think maybe something like that, or maybe I've accidently collected their eggs or babies in the water change.
Still something of a mystery though.
Thanks anyway!