Street Magazine STREET FUN FISH Street MagazineUse latex surgical gloves with out powder to check the external surfaces and eyes. Examine the fish for abnormal color changes, eye lesions, swelling of the coelomic cavity dropsy, and musculoskeletal abnormalities. Examine the gills by lifting the operculum. Spread the fins to check them, and evaluate the oral cavity. Compare ill fish with healthy tank mates. Sick fish frequently exhibit changes in color and appear lighter or darker than their fit tank mates.