Any chance of a pic? I'm afraid i dont know what you mean by spirm. It could be a high form of parasite, do they hang off the fins and have a y shape to them or are they close to the skin and round? usually dosing with salt will get rid of them.
Add 1 level teaspoon per gallon of aquarium salt and then 12 hours later do it again, and 12 hours after that again and see if they come off with that. Do not use salt though if you have scaleless fish such as dojos