Abstract
A single-cell PCR method was applied to Pseudo-nitzschia pungens strains from the southern Black Sea. Based on the aligment set of the LSU D1-D3 region, a Bayesian molecular phylogeny analysis and a parsimony network analysis were used to investigate phylogenetic clades (Clades I-III) in P. pungens and to determine the ancestral clades. The parsimony network analysis also demonstrated that ancestral haplotypes belonged to Clade II, residing around the northeastern Pacific, while Clade I was distributed globally but antitropicaly. According to the findings of this study, the Black Sea strain (Clade III) shows a global phylogeographic pattern.