I've worked out what they are...tank pests!

[~firefly~]

I thought I had planaria in my shrimp tank. Actually, I do have planaria - but they aren't the annoying problem (planaria aren't that much of an eyesore, not that noticeable). The annoying problem is...wait for it...

Freshwater Limpets!

Bizarre! Anyone had these and got rid of them. Will anything eat them? They are very obvious in my nano tank. Grrr...

They look like this:
Latia_embryos.jpg

[Aeonflame]

That's actually pretty cool. I had some years ago and my rams picked them all clean.

[~firefly~]

I have lots of baby assassin snails in my other tank. I'm thinking about putting one or two in the shrimp tank to see if they eat the limpets. I don't really want adults in there as they can prey on shrimp.