SINOPSIS

Dimensional and age structure of the narrow-clawed crayfish populations was analyzed. Crayfish growth is described by the Bertalanffy equation. Values of Bertalanffy growth parameters L_∞ and k are not species-specific, even in the same region and relatively close habitat conditions they can vary within wide limits. Very weak inverse relation was found between L_∞ and k, which makes invalid calculations of demographic characteristics on the basis of general equations of interrelation of populational and growth parameters. Growth constant k appears to be more informative than definitive body size (L_∞).