Ecological and non-environmental constitutional resistance of the protoplasm of marine algae

Abstract

Marine algae supply good examples of the difference between ‘ecological’ and ‘non-environmental constitutional’ resistance of the protoplasm of their cells to variations in the environment. The resistance to ecological factors such as diluted or concentrated sea water, to desiccation, or to light exposure is very similar among algae occupying the same habitat. On the basis of the degree of resistance shown, three ecological groups can be distinguished: (1) algae from the intertidal zone; (2) algae from the low-water level and tide-pools; and (3) sublittoral algae. On the other hand, there is no similarity in the resistance to chemical substances (H 3 BO 3 , ZnSO 4 , MnSO 4 , VOSO 4 ) of algae within a given ecological group. It is characteristic for a given species.