Before any growth can be,achieved by an organism
there must be sufficient energy in the food to provide for
the metabolic demands of maintenance and any activity associated
with food intake. In culture practices it is possible
to reduce these energy costs to a minimum and to optimize
food conversion. This can be done through an understanding
of the environmental and biological factors affecting metabolic
rate with a view to reduce the demands on the system
and hence increase the production. It is therefore desirable
to examine the broad picture of energy exchange within an
animal; then proceed to more specific considerations in fish.
Since it is the principles and prospects which are of major
interest here, no attempt is made to make this a major review
of the subject
