After looking at the few online photos and illustrations of the Mexican Golden Trout that I could find, I've decided James Prosek painted a mix of the male during spawning colors and the female specimen. That being said, having never seen one of these little Mexican beauties, who am I to presume such things?
The Mexican Golden Trout is the last of the species in the chapter on Apaches, Gila and Rios.
During spawning season, the male sports a bright orange belly.
From what I can tell online, the par marks seem to be persist past the juvenile stages.
The par mark on the left is a bit darker than the rest, now that I look at it.
Next up, the book delves into the Rainbow, Redband, and Golden Trout. I've selected 7 of the 15 fish to paint. After that will be the Cutthroats. Now that is a big chapter.