Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi-enclosed lagoon throughout nearly 2 years of observations. The highest cell densities (104-105 cells L-1) were recorded from September to beginning of December at temperatures and salinities of ~26-32 °C and ~41, respectively. The peak of the bloom was recorded mid-November, before a sharp decrease in cell numbers at the end of December. Minimum concentrations in summer were at ~103 cells L-1. A saxitoxin ELISA immunoassay of cultures and water samples confirmed the toxicity of the strain found in the Red Sea. Moreover, a gene expression analysis of the saxitoxin gene domain SxtA4 showed that transcript production peaked at the culmination of the bloom, suggesting a relation between transcript production, sudden cells increment-decline, and environmental factors. © 2016 Elsevier B.V.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Nikolaos Zarokanellos, Francis Luke Mallon and the CMOR team at Kaust for help and support, Ali R. Behzad and Ohoud Mohammed Eid Alharbi from the Imaging and Characterization lab at Kaust for their invaluable collaboration during the imagining process, and the core lab facilities; specially Sadhasivam Perumal for his valuable support and guide. This study was funded by King Abdullah University of Science and Technology (KAUST).[SS]