Does my Longnosed Butterflyfish have Ich??

[Dathmo]

Hi,

I got a longnosed butterflyfish and added him into my tank yesterday. He hasn't been eating anything (I've tried flakes, brine shrimp, bloodworm, mysis shrimp and garlic) and has been swimming pretty much in one corner for the last 24 hours. I've been keeping a close eye on him and have noticed a small white spot on the top of his back fin (see images). Do people think this is a sign of disease? If so, what should I do? I don't have a quarantine tank but my tank is fish inly so I don't have to worry about corals and don't have any inverts at the moment.

 

[Dathmo]

To add on to this he will occasionally do strange erratic movements with his head, and kind of shake or twist if that makes sense. I'm not sure if this is normal behaviour or not!

 

[Dmorty217]

To add on to this he will occasionally do strange erratic movements with his head, and kind of shake or twist if that makes sense. I'm not sure if this is normal behaviour or not!

This could be ich or flukes. Did you QT the fish?