TRAVERSE CITY, Mich. — If “invasive carp” doesn’t sound appetizing, how about a plate of copi? The state of Illinois is unveiling a market-tested rebranding campaign to make the fish appealing to consumers. Four species imported from Asia decades ago now infest the Mississippi and other rivers in the U.S. heartland. They also threaten the Great Lakes. Officials say the fight to contain them would get a boost if more people would eat them. The Illinois Department of Natural Resources hired a marketing firm to find a new name. And “copi” is the winner. Chefs, distributors and others in the food industry say it’s a tasty, healthy fish.