Polymorphism of the <Emphasis Type="Italic">cox1</Emphasis> mtDNA gene from cercarial isolates of the avian schistosome <Emphasis Type="Italic">Bilharziella polonica</Emphasis> (Trematoda: Schistosomatidae) from Belarussian lakes

We have studied the phylogeographic structure of avian schistosomes Bilharziella polonica (Trematoda: Schistosomatidae), parasites of 18 molluscs Planorbarius corneus (family Planorbidae) from three Belarussian lakes. Low nucleotide (π < 0.5%) and high haplotype (h = 85.6%) diversity of the gene encoding the cytochrome C oxidase first subunit (cox1) was found on the part of the species range studied. The phylogenetic reconstructions showed that the sample examined consists of at least two lineages of haplotypes, A and C. Haplotype diversity was somewhat higher in lineage C. The genetic divergence between these genealogical lines reached 0.55%, while the time of possible divergence was 180000–270000 years. Possible evolutionary scenarios for differentiation of the B. polonica lines and effectiveness of using cox1 for barcoding trematode populations and finding coevolutionary parasite-host relationships are discussed.