In North America, freshwater fish include snook, redfish, salmon, trout, bass, pike, catfish, walleye and muskellunge. The smallest fish are called panfish, because they can fit whole in a normal cooking pan. Examples are perch andsunfish.
In the past, sport fishers, even if they did not eat their catch, almost always killed them to bring them to shore to be weighed or for preservation as trophies. In order to protect recreational fisheries sport fishermen now often catch and release, and sometimes tag and release, which involves fitting the fish with identity tags, recording vital statistics, and sending a record to a government agency.
Reference: Wikipedia Sport Fishing