During the fall reproductive season, the belly of a male brook trout becomes bright orange. The orange belly provides some camouflage and helps attract females. This trait evolved in brook trout because, compared to males with pale bellies, males with bright orange bellies are more likely to

-- live in good habitats.;
-- be eaten by predators.;
-- mate with other species of fish.;
-- fertilize eggs to produce offspring.;
fertilize eggs to produce offspring.