Trying to work out what killed my Dwarf Lemon peel angel fish

[marinefisher]

Hi everyone,

Unfortunately I lost my lemon peel
Angel fish today after a few days of it acting differently.
First it was hiding in a cave and wouldn’t come out.
Next came it swimming on its side struggling to swim.
Please see attached pictures of when it was struggling and how it was found today. No obvious signs apart from looking red/ blood near the gills. Please help to try and diagnose what went wrong guessing a disease of some sort. All parameters were fine, corals and other fish all fine. It was still quite young and had for 2 months.

 

[KrisReef]

The fish looks emaciated.
If it came from the Phillipeans I would guess it was cause using cyanide. That distroys the fishes digestive tract and they slowly starve, and die often looking like your pictures.

When purchasing new fish, be careful to look for sunken guts and fish that light pick or don't eat at all.

Also possible that it had some paracytes?- but that diagnosis isn't one I can offer, ime?