Black Balloon Molly

[Pleco]

I had bought a balloon molly a while ago and now its top fin (dorsal fin, i think?) is sticking up. Is this normal or not?

[Obsidian]

Dorsal fins should both go up and lower at various times during their daily lives. When they are swimming forward it will probably be lower and pointing towards the back of their body, when they are just hanging out it will be "up" and that is a good thing.

[fish_doc]

Agreed, Sometimes up sometimes down is fine. When darting around it can be down. It creates less drag so they can move faster, But if it is always down or clamped it could be a sign of a ill or sick fish. So since you are saying its up I would say its all good. You can easily see if their is any fin rot or any other things going on.

Happy Fish.