You know I'm not really sure, Most of the first day fisherman are after the stocked trout, browns, rainbows, and palaminos. It use to be that a stocked trout was a tasteless bag of mush and was dummer then a rock, but I'll give the Fish Comission credit for breeding better trout over the last few years.
The first day/week for us is more about taking the kids fishing, we don't get real serious about our trout fishing till the weather warms up then we hit some of the non stocked streams and fish for native brookies. YUM! I don't remember a time their wasn't a season, I've never really thought about it, though it was probably because of our nasty winter weather. This sounds like a question my daughter would come up with, I think I'll do some research and get meself an answer.