Fig. 4.

Phylogenetic tree of 17 Alexandrium species and strains (Atm, A. tamarense; Act, A. catenella; Afu, A. fundyense; Amn, A. minutum; Aaf, A. affine) and local Alexandrium species Ach01. Sequences were obtained from the GenBank database using the keywords ‘Alexandrium LSU rDNA’ or ‘Alexandrium 28S’. Phylogenetic trees were generated for an alignment of 18 sequences of 1776 bp in the ITS1-D5 region through Bayesian inference in MrBayes V3.2 and maximum likelihood (ML) in PhyML. Bayesian analysis was carried out with 1 500 000 runs, with five separate initial trees. Convergence was checked through PSRF and AVSF. FigTree V1.3.1 was used as a visual representation of output trees. For ML analysis these were carried out with 1000 bootstrap replicates.