Genetic and morphological variability in cestodes of the genus Proteocephalus: geographical variation in Proteocephalus percae populations

Genetic and morphological variability was studied in the tapeworm Proteocep halus percae (Muller, 1780) (Cestoda: Proteocephalidae), a parasite of perc h (Perca fluviatilis L.). Geographic variation in isoenzyme patterns, rando m amplified polymorphic DNA (RAPD) profiles, and morphological characters w ere found within six natural populations of P. percae from Slovakia and Swi tzerland. All approaches used showed that similarity was substantially high er among Swiss populations than among Slovak populations. Proteocephalus pe rcae specimens from the Dobsina water reservoir (Slovakia) differed signifi cantly from all other population sample sets in that they exclusively expre ssed the genotype Acp(92)/Acp(92) and possessed a specific RAPD profile aft er amplification with the primer p78 and distinct measurements of the scole x (scolex width and apical sucker). The unique position of the P. percae po pulation from Dobsina could be related to the contamination of this localit y with heavy metals (cadmium), through the possible impact of these metals on the alterations observed. The taxonomic relevance and stability of the m orphological characters related to the scolex in the Proteocephalus tapewor m group is confirmed.