CHLORIDE CELL APICAL SURFACE CHANGES IN GILL EPITHELIA OF THE ARMOREDCATFISH HYPOSTOMUS-PLECOSTOMUS DURING EXPOSURE TO DISTILLED WATER

Armoured catfish Hypostomus plecostomus were exposed to distilled wate r for 15 days. High chloride cell proliferation occurred on the filame nt and lamellar gill epithelia. The apical surface of the chloride cel ls (66% of cells in both epithelia) showed significant reduction in th e aquatic environment which was characterized by the development of a sponge-like organization. The chloride cell response suggests that the se features could create a microenvironment which may favour either th e reduction of ion loss or ion uptake in a environment characterized b y an absence of ions. (C) 1998 The Fisheries Society of the British Is les.