What are you feeding them? Ours like BOSS even though we have a couple suet feeders. As for the pileateds, we have seen them occasionally in our area----and have heard them even more--but have yet to draw them in. Last night, we had 4 male rose breasted grosbeaks, three females, and our first hummingbirds and orioles. Still waiting on the indigos.

The genus of all flies is Musca. This one doesn't have a red head...those are the large compound eyes, just like most other flies. Don't know the species.

It could be an injury, parasite, or just a change of color. Check your water chemistry and any areas in the tank where your fish may have injured itself. Is the tank large enough for all three fish? The link below shows a list of diseases and how to treat. If it's not getting any worse and he's eating, it may take care of itself. Here is a link that might be useful: Fish care

Looks healthy and happy! I am happy to see you post a bit, sending you healing vibes, take care of yourself.and keep in touch.