Dose my puffer have herpies.

I hope someone out there can help me with a concern I have with a Nile Puffer I perchused about four months ago. Shortly after buying him i noticed a small cyst like bump on the "muscular stump" of his dorsal fin. The bump seems to change in size, even compleatly disapear. I have tride to diagnose the bump through disease forums, but i can't find anything that has a bump that comes and goes (sounds like a virus). A few days ago I noticed that one had breefly developed on his side (smaller and has since disapeared). Other than this he/she is very vibrant and has good colouration, the bump does not seem to bug him/her. Is this bump really a problem, and if so what should i do.

Also, I have noticed that many types of puffers have a white spot in the center of thier anal fin. Dose anyone know what this is? Dose it tell what sex your puffer is?