Chloride cells and chloride exchange in the skin of a sea-water teleost, the shanny (Blennius pholis L.).

The fine structure of the skin and its importance in chloride outfluxes were investigated in a sea-water teleost, the shanny (Blennius pholis L.). The epidermis is composed of three cells types: epithelial cells, mucous cells and chloride cells. These chloride cells typically contain a great number of mitochondria and an extensive agranular reticulum extending through the whole cell body. They open at the surface of the epidermis into an apical pit. An undifferentiated small cell is often observed near these chloride cells and probably corresponds to the "adjacent chloride cell". The values of chloride outfluxes through the skin and the gills are respectively 5333+/-884 muEq.h-1.kh-1 and 4479+/-2521 muEq.h-1.kg-1; n = 6; t degrees = 13+/-0.5 degrees C. Thus the ratio between skin chloride outflux and total chloride outflux is 64.7 +/- 9.3%.