An Electron Microscope Study of Fish Skin Affected by Changes of pH Values

Abstract

The epidermis of Clarias macrocephalus (GÜnther), Pangasius pangasius (Buchanun) and Ophicephalus striatus Bloch unexposed and exposed to the acidity or alkalinity of the water, with the temperature range of 24-29^oC, for 96 hours was ultrastructurally studied. At low and high pH, both filament-containing cells in the uppermost surface layer and goblet mucous cells were involved in releasing more mucus. The former produced numerous vesicles passing through terminal web, while the latter increased in number closed to the surface layer. At pH 3.46-3.38 chloride cells which have osmoreguratory function became active in secretory activities, showing distended tubules in their cytoplasms. An unidentified matrix was found in a club cell at high pH. When the experimental time was prolonged to 11 days of low pH exposure (4-6.8), a symptom of necrotic cells at the basal layer occurred, showing abnormalities in their cytoplasms.