Toxic effect of the marine dinoflagellate Gymnodinium galatheanum on juvenile cod Gadus morhua

Juvenile cod Gadus morhua exposed to the dinoflagellate Gymnodinium galatheanum Braarud died within 2 d; before death the fish became lethargic and affected fish showed increased plasma osmolality.Severe histopathological changes were found in the gill tissue, with extensive separation of the respiratory epithelium from the underlying pillar cells.Though no recent blooms have been recorded, G. galatheanum should be considered as a potentially harmful bloom-forming alga in temperate waters.