Changes in scaling of respiratory systems during the development of fishes

Abstract
Relationships between respiratory area, oxygen consumption, and body mass have been examined during the development of water- and air-breathing fish. It is concluded that there is at least one stage at which the slope of the relationship between log gill area and log body weight changes during fish development. This usually occurs in the weight range 0.05–1.0 g and is often associated with a distinct metamorphosis, but no common functional significance can be attached to them. However, the change in slope does not appear to be associated with a comparable inflexion in the corresponding relationship between body mass and oxygen consumption (routine). It seems probable that other surfaces are important during these transitions and that the total gas-exchange surface of the fish shows a more constant change throughout the life history. Further analyses of a wider range of species is required to test this hypothesis.