Abstract

In Chile, the toxic dinoflagellate A. catenella shows an apparent oceanic range expansion from south to the north since its first detection in 1972 in the Magallanes Region (56 degrees S). Until 2017, A. catenella detections were restricted to a geographic area between Magallanes to Los Rios Regions (40 degrees S). The establishment of a monitoring program in the offshore Pacific coast allowed the detection of A. catenella between 2018 and 2019 in northern areas off the Bio-Bio Region (36 degrees S). Monoclonal cultures established from the Bio-Bio coast were genetically identified, and PSTs screened. Phylogenetic analyses determined that the Bio-Bio isolates aggregated in Group I ribotype (previously A. tamarense or A. fundyense) and the presence of PSTs analogs were confirmed. It is the northernmost detection of the toxic dinoflagellate A. catenella in the Pacific coast of Chile. These results have important implications for species monitoring and governmental management in the Bio-Bio Region.