GENETIC-VARIATION IN 3 SPECIES OF FRESH-WATER CRAYFISH - ASTACUS-ASTACUS L, ASTACUS-LEPTODACTYLUS AESCH, AND PACIFASTACUS-LENIUSCULUS (DANA), REVEALED BY ISOZYME ELECTROPHORESIS

Isozyme electrophoresis was applied to three species of freshwater crayfish, Astacus astacus L., Astacus leptodactylus Esch., and Pacifastacus leniusculus (Dana), in order to detect genetic variation and to find the most suitable enzyme systems for intra- and interspecific studies of these species. To obtain maximum information a number of different tissues and organs were used. Initially 21 enzymes and general proteins were surveyed and 15 of them, with a putative number of 29 loci, were found to be suitable. No genetically interpretable variation was observed in any of the A. astacus populations. However, in A. leptodactylus and P. leniusculus, polymorphisms were detected in one and three loci, respectively. The genetic identity (NEI 1972, Am. Nat. 106: 283-292), calculated for enzymatic loci only, was estimated at 0.7243 within genus Astacus and 0.5983 +/- 0.019 between the genera Astacus and Pacifastacus.