STRUKTUR INSANG IKAN BAUNG (Hemibagrus nemurus Blkr.) AKIBAT TERPAPAR KONSENTRASI SUBLETHAL MERKURI (Hg)

Abstract

Mercury is one of dangerous pollutant in the aquatic environment and can be accumulated in aquatic organism. High concentrations and long time exposure of mercury causes on death fish. This research aims to understand the behaviour and changes occur in the gill structure of the Hemibagrus nemurus Blkr. that were treated with mercury (Hg) in sublethal concentrations (0.490 ppm). Total fishes use in this study was 20, 10 fishes for control and 10 fishes for treatment. After being treated for 96 hours, fish behavior, morphological and histological structure of the gills was studied. The results indicated that the treated fishes shown abnormality, such as hyperactive become weaken and finally die within 96 hours. The gills of the treated fishes was red pale, while that of the control light red. Histological study shown that there were abnormality in the gills tissue, such as hyperplasia, hypertrophy, fusion of secondary lamella, lifting of epithelial cells, epithelium rupture, hemorrhage, hypertrophy of the chlorid cells and necrosis. Based on data obtained it can be concluded that the LD50 of mercury (0.490 ppm) negatively affect the gill of H. nemurus