A trout fishery reports that many of the fish have gray-white, puffy growths on their fins, gills, and eyes. A direct smear from affected tissues shows the following findings (images below).
What action should you take to address the top differential?
A - Supplement the fish with vitamin C
B - Depopulation is the only appropriate measure
C - Administer praziquantel to all the fish
D - Ask if there is any zinc in the housing
E - Treat with potassium permanganate
answer/E