Ambient Water Concentrations Research Articles

Comparison of gas transport by convection among animals

The transported volume (V) of water, air or blood per unit quantity of O 2 uptake (Mo 2), i.e. the ratios V/M O 2 , hereafter called convection requirements, and the O 2 extraction coefficients from water, air and blood have been studied in various water- and air-breathers as functions of the O 2 concentration in ambient water or air and arterial blood. The convection requirements and the O 2 extraction coefficients decrease with an increased availability of O 2 in the ingoing medium. Convection requirements may be 30 times lower and the extraction coefficients 2 times lower in air-breathers than in water-breathers. Variations of ambient temperature and acclimatization process may change considerably the convection requirements and the O 2 extraction coefficients. The concept of a convection requirement may be important when one wishes to compare respiration in animals of different size and different O 2 consumption. An example of application to the problem of control of breathing is given.