Histopathological effects of cadmium on gills of the freshwater fish Macropsobrycon uruguayanae (Pisces, Atherinidae) (Eigenmann, 1915)

RANDI, A.S.; MONSERRAT, J.M.; RODRÍGUEZ, ENRIQUE M.; ROMANO, L.A.

JOURNAL OF FISH DISEASES

WILEY-BLACKWELL PUBLISHING, INC

Año: 1996 vol. 19 p. 311 - 322

0140-7775

Evaluations of histopathological lesions in gill tissue were carried out in the freshwater fish Macropsobrycon uruguayanae following 30 and 60 days of exposure to 1.5 mg 1-1 of cadmium. The study was conducted on both fed and starved animals in order to determine the influence of feeding condition on cadmium toxicity. The main lesions observed and quantified were: (1) hyperplasia of primary lamellar epithelium; (2) hyperplasia of secondary lamellar epithelium; (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) inflammatory infiltration. Lesions 6, 8, 9 and 11 were only induced by exposure to cadmium, while lesion 4 could be produced only by starvation. Starved fish also showed a reduction in total body weight and length. Lesion 2 was shown to be non-specific, and produced by either cadmium, starvation or even exposure time. The possible mode of action of the experimental factors are discussed in relation to the observed pathologies.