Icestorm Island Fish are fish that were released in April 24th 2015 and are found in Icestorm Island. On an unknown update, the Icestorm Island Fish can be found in Scuttleclaw Island and in Glacier Island as both locations technically belong in the Arctic territory.
Because the respective fishes share the same location (ocean/lake) as the other fishes, do expect to find the other species of fish.