copperband twitching its head

[daniella3d]

My new copperband butterfly is often twitching its head and a bit for the bottom fins as well. I was wondering if I should treat it with hyposalinity? could it be fluke? He's breathing a little fast as well, not sure if it is normal or not. I have it for 3 days now and the fish is eating PE mysis and live white worms.

He's on the skinny side with the top part being pinched, so I am worried that the fish has some parasites. I don,t know what's best, prazipro? hyposalinity? or just wait a little more?