No, doesn't look like something is stuck. And I;ve watched him eat algae, and his belly is quite plump.
It is a quarantine tank, so bare bottom, no plants. New fish, just a keyhole cichlid from a nearby LFS. Possibly the problem, but the cichlid appears to be very healthy.
As for the heater thing, that is possible, but to me it looks more like the blood is on the inside.
I would vote on bacterial, but it could be gill flukes, too.
Just a question, if I have to, will Maracyn Two have any bad effects on Prazipro? I would like to finish the Maracyn Two, but I'm asking just in case there's a real emergency. Thanks.