Because so much of a female salmon's fats and oils go into the development of its eggs in terminal areas (rivers etc) a male at comparable maturity is better table fare. With salmon and steelhead the males of the species develop much bright spawning colors than the females - much like with peacocks and pheasants it is to insure a higher probability of being selected by a female or out competing other males. As a result a slightly colored male will be better eating than a chrome female.

The only reason to keep a female over a male is because of its eggs. This busy of high grading for females essentially doubles the anglers impact on the resource - something to consider when angling on a wild resource.

Tight lines
Smalma