A number of special courses have been developed that deal specifically with aquatic animal medicine, and include such courses as AquaVet 1, AquaVet II, AquaMed, Aquatic Pathobiology, Envirovet, and a variety of other courses. Each course varies in species emphasis, topics covered and laboratory experience. Species covered in these courses include freshwater and marine finfish, crustaceans, shellfish, reptiles and marine mammals. Topics range from comparative morphology and physiology of aquatic animals; husbandry, culture and nutrition; infectious and noninfectious diseases; diagnostic techniques and pathology; to therapeutics and health management. Selection of participants for these courses is generally based upon educational background, past experience and interest expressed by the applicant.