Is my black moor sick?

Question
I've had my black moor for just over 1 week. I've noticed a few times that he has a white, translucent "string" coming out of his body (more specifically, bellow his belly and under his fins). Normally, he swims around until it breaks off; however, it returns a few days later.

Should I worry?

Answer
Alexis,                                                      He is going to get big I hope you have enough room for him to begin with. Treat him for fungus they are prone to it. You can go to the petshop and get erythromycin or fungal cure. Treat for 7 days take your carbon out of your filter. Then a 25% water change. That should take care of this. After this is all over give him a frozen pea squeezed once a week and a slice of orange in a veggie clip you can also get from your petshop. It will keep him nice and healthy. This prevents bacterial infections and the orange is high in vitamin c . Good Luck, Tina