Who Gives A Fish Forums

Just pulled out some copepods for my fry from the 5L infusoria bucket culture and stumbled upon a few of these tiny critters swimming around. Any idea what they are and should I be worried about them affecting my copepod population in that bucket?

I'm pretty sure that's a flatworm you've got there. It's possible it's feeding on your copepods, but with just one or a few of them, I wouldn't worry too much about the impact on the population in your bucket.

I had a similar sighting in my 60L a while back, but it was too quick for me to snap a photo. They were buried in the substrate back then. I reckon they must've hitched a ride over in the filter sponge, since that's where the culture originated.

Just caught a couple more. First time doing pipette fishing, but it's kinda fun.

Edit - Threw a light on the bucket and managed to snag six more. Looks like my Infusoria bucket's got a bit of a problem on its hands.

Could be either planaria or rhabdocoela, both are flatworms and known to prey on small inverts like copepods.

coltin wrote: ↑Fri Sep 20, 2024 5:30 pm Could be either planaria or rhabdocoela, both are flatworms and known to prey on small inverts like copepods.

Turns out you were right, they're indeed Rhabdocoela. Managed to catch over 15 so far.