As just forewarned a few days back, we lost our biggest cheek in the 25K. No funny business from tank mates but all internal / inherent problems. It feels neurological to me because the fish gradually, over the past months, lost the ability to hold upright, swim right, or even maintain the body shape - the muscles were like mush and the backbone felt like a rope, not upheld by tendons and muscles.
In water, it had a crescent shape, just like in the photo, except in the other direction with head and tail pointing down. It stopped feeding or feeding well some weeks ago.
You can also see the badly misshapen gill plates on it, which it had developed on its own long ago, still at about 6"-9".
Final size 17" at 1.5 years old.
The only remaining cheek is probably 12", still in the 25K, doing seemingly well but I have no hope for it - it's not growing much, it seems to have a concave, non-straight top from head to dorsal fin, and seems to have some protrusion in the lower jaw.