STRUCTURAL AND ULTRASTRUCTURAL-STUDY OF THE GILLS OF TENCH (TINCA-TINCA L.) AFTER EXPERIMENTAL POISONING WITH COPPER-SULFATE

This paper reports the results of a structural and ultrastructural stu dy of gill parenchyma in tench (Tinca tinca L.) subjected to experimen tal anhydrous copper sulphate poisoning. Capillary congestion and abun dant interlamellar edema observed in the early stages subsequently gav e way to epithelial hyperplasia, which gradually increased until the l amella was wholly occluded. Final stages were characterized by marked necrosis of the lamellar epithelium, leading to the death of the first subjects seven days after the start of the experiment. The observatio n of anhydrous copper sulphate deposits from Day 1 suggests that the g ill is one of the main organs for absorption of this substance.