Electron microscopical and histochemical studies of differentiation and function of the cephalopod gill (Sepia officinalis L.)

Summary Phase contrast and electron microscopical investigations on the gill ofSepia officinalis L., from the stage shortly before hatching to the adult stage, demonstrate (1) peripheral respiratory epithelial areas and (2) highly folded epithelia rich in mitochondria in the concave recesses of the gill lamellae. Enzyme-histochemical and cytochemical findings, and in particular the GOT proof, suggest by analogy with the chloride cells of the teleosts that the cells of this second type of epithelium are capable of active transport, and that they probably secrete ammonia. Apparently the gill of cephalopods, too, serves both respiratory and excretory functions.This study was supported by the Deutsche Forschungsgemeinschaft