Ceed

Selective breeding in hatcheries and through crossing different varieties (there are many varieties) (as well as up to 8 recognized subspecies; some only recognize 3) of rainbows, i.e. Coastal rainbows, McCloud River Redband, Beardslee, Kamchatkan, etc, various resulting populations have been reared and stocked in NY waters over the years (and continuously crossed and back-crossed, and artificially selected for differing traits including color, growth, feeding, and reproduction). As a result, different Lake Ontario rainbow (steelhead -a name adopted from the term historically used to describe anadromous rainbow subspecies/varieties) varieties have been developed including spring-spawning varieties, as well as fall-spawning varieties. "Rainbow" refers to permanent stream resident populations. Also, triploidy production in rainbows can be employed (though I haven't heard of any mass production in NY state), where sterile individuals are created by subjecting fertilized eggs to either very high pressure or uv light. These individuals rapidly grow to larger sizes as no energy is spent on sexual maturity and reproduction. Another point: appearance of individuals changes with conditions (surroundings, sunlight, water visibility; spawning -fish become darker, spots become more prominent and pink stripe more intense, males' jaws lengthen and lower jaw develops a kype).