ASPECTS OF ANIMAL EVOLUTION RELATED TO CRITICAL SALINITY AND INTERNAL STATE

This paper presents facts and problems related to the concept of critical salinity, i.e., the salinity range 5 to 8‰ S. It points, in particular, to the distribution of marine and freshwater species revealing a faunistic boundary (minimum number of species), organismic resistance to salinity, osmoregulative capacity, physiological activity, electro-chemical properties of tissues, and evolutionary aspects. The concept of critical salinity opens up new perspectives for the understanding of present day salinity effects as well as for the interpretation of animal evolution. © 1969 Springer-Verlag.