What kind of fish does long john silver serve?

Long John Silver's and Captain D's use a very common variety of fish simply known as "whitefish". While there is a specific genus of fish with that name, many similar fish are lumped together under the name whitefish. It is an industry standard name for a mild tasting white-colored fish that is found in many parts of the world. They are NOT bottom feeders or trash fish... simply common, almost "generic" fish.

long john silver in Dayton Ohio uses Alaskan Pollock.