The respiratory area of the gills of some teleost fishes in relation to their mode of life

From computations (by means of graphic interpolation and graphic integration) of the respiratory area, and transposition of these values to a respiratory area of a standard fish of 200 g (A200 value), it could be made plausible that the relation between respiratory area and mode of life of the fishes mentioned in this paper (Cod, Plaice, Conger, Flounder, Dab and Pike) fits in with the general pattern found in an earlier paper, although intraspecific differences were sometimes considerable. In comparison with A200 values of other species, the Cod has a respiratory area that fits in with his mode of life and that of other typical sprinters. The Flounder has a considerably larger respiratory area than Plaice and Dab. Flounder feeds mainly on small fishes, while Plaice and Dab feed on molluscs and worms. Conger has to be considered a crawler. The Pike, as a typical sprinter, shows nevertheless large differences in its A200 values. It was known already that freshwater biotopes do not allow fishes to develop into typical stayers. Thus, large differences between freshwater sprinters and crawlers can hardly be expected. The relation between respiratory area and body surface cannot be used in a comparison between fishes of different species.