Histopathological effects of cadmium on the gills of the freshwater fish Macropsobrycon uruguayanae (Pisces, Atherinidae)

ANDREA RANDI; JOSÉ MONSERRAT; ENRIQUE RODRÍGUEZ; LUIS ROMANO

JOURNAL OF FISH DISEASES

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 1996 vol. 19 p. 311 - 322

0140-7775

Evaluations of histopathologieal lesions in gill tissue were carried out in the freshwater fish Macropsobrycon uruguayanae following 30 and 60 days ofexposure to 1.5 mg 1~' of cadmium. The study was conducted on both fed and starved animals in order to determine the influence of feeding condition oncadmium toxicity. The main lesions observed and quantified were; (1) hyperplasia of primary lamellar epithelium; (2) hyperplasia of secondary lamellarepithelium; (3) separation of respiratory epithelium; (4) shortening of secondary lamellae; (5) epithelial necrosis; (6) fusion of adjacent secondary lamellae;(7) hypertrophy of respiratory epithelium; (8) lamellar telangiectasis; (9) hyperplasia of chloride cells;(10) mucinous metaplasia; and (11) infiammatoryinfiltration. Lesions 6, 8, 9 and 11 were only induced by exposure to cadmium, while lesion 4 could be produced only by starvation. Starved fish alsoshowed a reduction in total body weight and length. Lesion 2 was shown to be non-specific, and produced by either cadmium, starvation or even exposuretime. The possible mode of action of the experimental factors are discussed in relation to the observed pathologies.