PARASITIC CRUSTACEA
Parasitic crustacea are increasingly serious problems in cultured fish and can impact wild populations. Most parasitic crustacea of freshwater fish can be seen with the naked eye as they attach to the gills, body and fins of the host. Three major genera are discussed below.
Ergasilus
Ergasilus are often incidental findings on wild or pond-raised fish and probably cause few problems in small numbers. However, their feeding activity causes severe focal damage and heavy infestations can be debilitating. Most affect the gills of freshwater fish, commonly seen in warm weather. A 3% salt dip, followed by 0.2 %-prolonged bath for three weeks, may be effective in eliminating this parasite.