I'm in RI, which is no guarantee that the regs are the same but......we can keep fish of legal size, provided that don't have a "season." In other words, I cannot keep any fish that is undersized to take for eating and nothing like a trout can be kept at any time since its illegal to return them to a lake or pond once removed and they have to be killed immediately if legally kept for food. I find that, in our area of the country, easily caught species that are hardy and do well in tank life (if you have the space) are bass, pickerel (better choice than pike due to controlled size), yellow and white perch, all varieties of sunfish, catfish like bullhead, and any baitfish/shiner.