HISTOPATHOLOGY OF THE GILLS OF ASCORBIC-ACID DEFICIENT GROUPER, EPINEPHELUS-MALABARICUS

Light and electron microscopic studies were carried out on the gills o f grouper (Epinephelus malabaricus) fed diets supplemented with or wit hout crystalline ascorbic acid for 12 weeks. Fish fed the diet without ascorbic acid supplementation showed various clinical signs such as h aemorrhages of fins, deformed opercula and caudal fin erosion. Histolo gical observations of the gills of scorbutic fish showed hyperplasia o f epithelial cells of primary and secondary lamellae, fusion of second ary lamellae, gill cartilage distortion and detachment of the epitheli um from the basal membrane of the secondary lamellae. By electron micr oscopy, degeneration of chloride cells, mucous cells and epithelium ce lls as well as hyperplasia and edema of epithelium cells were observed .