Fresh water question,but please help!

[spamreefnew]

My daughter has a small freshwater aquarium that I take care of. Recently I have noticed what looks like small gray nematodes
or leaches all over the fish! The things are gray and about 1/2" long and about the thickness of dental floss. The fish are starting to die one by one now. I have searched and searched the web but nothing. I am hoping the smart people here at rc can help me!

 

[Newsmyrna80]

You may want to check a freshwater forum. We are saltwater forum.

 

[HumbleFish]

Could be anchor worms. If memory serves, you have to remove them manually and then treat the tank with dimilin.