BLUE SLIME DISEASE
1) costiasis (an infection of the skin, fins and gills of aquarium and hatchery fish by the flagellate protozoan Costia sp. (or Ichthyobodo; and also Chilodonella, Trichodina). Found in young fish just as they start feeding externally, in colder waters.Stress may be a factor. Fish may show lethargy, appetite loss, flashing, respiratory distress in the form of gill flaring and gasping, fin erosion, and produce abundant mucus, giving a cloudy appearance, hence the names blue slime disease or skin slime disease. The skin and scales may peel away in strips in acute cases)
2) a skin condition associated with a lack of biotin (q.v.) in the diet