In the U.S. Geological Survey’s Non-Indigenous Aquatic Species database, these so-called ‘native transplant’ fish are almost twice as common as fish introduced from outside the country. But a new review says native transplant fish, especially those that don’t qualify as game fish, are rarely studied and their impacts poorly understood.In the U.S. Geological Survey’s Non-Indigenous Aquatic Species database, these so-called ‘native transplant’ fish are almost twice as common as fish introduced from outside the country. But a new review says native transplant fish, especially those that don’t qualify as game fish, are rarely studied and their impacts poorly understood.