On the regulatory nature of individual growth: some observations from freshwater snails

Various types of growth models are assessed. Results derived from observations made on growth in the freshwater snail, Planorbis contortus , suggest that in certain instances models based on a mechano-reductionist philosophy are acceptable whereas in others they are untenable. In the latter case a holistic representation is more biologically satisfying. Q10 values provide a useful assessment and summary of an individuals regulatory capacity with respect to growth when temperature disturbances are experienced. Another parameter, k corr is developed to carry out this function when other, particularly food supply, disturbances are involved.