I looked at my betta fish today, right before I changed its water, and he was looking at me and there was this huge black thing sticking out from one gill to the other. It was going down under his belly area and reaching up to his other gill. I looked again and it was gone, but the black area is still there, just not sticking out and huge. There is also a small, round, black/or really dark brown bubble looking thing on his left gill.

I've been looking to see if I could find any information on it, but I haven't been able to find any. I don't remember seeing it when I first bought him (roughly 1 month ago). If anyone can give me information on it, that'd be a great and terrific help. I'm really worried about it...