PRELIMINARY-RESULTS ON THE GENETIC-VARIABILITY OF MITOCHONDRIAL-DNA IN THE SIGNAL CRAYFISH, PACIFASTACUS-LENIUSCULUS DANA

This study presents a revised method for the extraction of mitochondri al genome (mtDNA) from crayfish species of aquacultural interest Pacif astacus leniusculus. The mean size of the mitochondrial genome is appr oximately 18 000 bp. Restriction fragment length polymorphism (RFLP) a nalysis performed an the mtDNA has revealed extensive genetic variabil ity within this species. The estimated percentage of nucleotide sequen ce divergence among the four haplotypes found for P. leniusculus rages from om 1.16 to 3.99%. These data suggest that RFLP analysis of mtDNA may provide greater resolution than protein electrophoresis for popul ation identification among signal crayfish populations. This marker of fers new avenues for aquaculture and for understanding the genetic str ucture and evolutionary history of crayfish populations.