Techniques for diagnosis of fish parasites include history, behavioral observation, visual
examination, skin scraping, gill and fin biopsy, fecal examination (direct or flotation of a fl'esh free-catch specimen or vent swab), necropsy examination with squash preparations of internal organs, and histopathology. Excellent texts are available for information on fish diagnostic techniques. 14 As in terrestrial clinical parasitology, identification of the parasite to species is often not required to determine a rational therapeutic course. Therefore, a brief outline of the major fish parasite groups is presented, and their management and treatment in some detail are explored.