Today I caught a mysterious worm in my gold mountain minnow fry tank. It's about a centimetre and a half long, thin and white like a piece of thread and it swims in the water like a sea snake. You can only see it from above, it's either too transparent or too thin to see side on. It definitely has an end that is in the lead, as opposed to watching a bloodworm swim which is very disorganised and figure 8 like.
I have searched for it on google and can't find anything that it resembles, does anyone recognise what it might be?
A photo will be difficult. Will try tomorrow