|Les eaux saumâtres comme milieu principal d'évolution des organismes marins|
Pora, E.A. (1972). Les eaux saumâtres comme milieu principal d'évolution des organismes marins, in: Battaglia, B. (Ed.) Fifth European Marine Biology Symposium. pp. 1-10
In: Battaglia, B. (Ed.) (1972). Fifth European Marine Biology Symposium. Piccin Editore: Padova. 348 pp., more
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VLIZ: Proceedings 
|Document type: Conference paper|
Due to the fact that environmental factors in brackish water are permanently variable, only eurybiontic organisms are able to live there, i.e. those, which possess highly efficient metabolic regulatory mechanisms. These organisms are spending much energy with the functioning of the regulatory mechanisms. They are able to adapt themselves easily to the variations of environmental factors. When isolated in an environment with modified factors, these organisms turn into new species. In marine and oceanic waters, the environmental factors are very constant. Organisms living here need no regulatory mechanisms, which weaken and even disappear. As a result, the energetic expenditure diminishes. But these organisms rest as such a very long time, and a sudden change of some environmental factors can lead to their disappearance. They are stenobiontic organisms. The eurybiosis that we meet in brackish waters is a state of adaptation, which allows the appearance of new forms and species. The stenobiosis that we meet in marine waters is a state of adaptation, which preserves existent species in the state they are in. Examples are given for this thesis from the Black Sea.