biostudies-literatureUnknown22(7)Cusick KDDinoflagellate species that form some of the most frequent toxic blooms are also bioluminescent, yet the two traits are rarely linked when studying bloom development and persistence. <i>P. bahamense</i> is a toxic, bioluminescent dinoflagellate that previously bloomed in Florida with no known record of saxitoxin (STX) production. Over the past 20 years, STX was identified in <i>P. bahamense</i> populations. The goal of this study was to examine toxin dynamics and associated molecular mechanisms in spatially and temporally distinct <i>P. bahamense</i> populations from the Indian River Lagoon, FL. <i>SxtA4</i> is a key gene required for toxin biosynthesis. <i>SxtA4</i> genotype analysis was performed on individual cells from multiple sites. Cell abundance, toxin quota cell^-1, and Marine drugs311https://www.ebi.ac.uk/biostudies/studies/S-EPMC11277979biostudies-literatureToxin Dynamics among Populations of the Bioluminescent HAB Species <i>Pyrodinium bahamense</i> from the Indian River Lagoon, FL.PMC11277979Brown NBoyer GLWei BCusick KDWidder EAHall SfalseToxin Dynamics among Populations of the Bioluminescent HAB Species <i>Pyrodinium bahamense</i> from the Indian River Lagoon, FL.Dinoflagellate species that form some of the most frequent toxic blooms are also bioluminescent, yet the two traits are rarely linked when studying bloom development and persistence. <i>P. bahamense</i> is a toxic, bioluminescent dinoflagellate that previously bloomed in Florida with no known record of saxitoxin (STX) production. Over the past 20 years, STX was identified in <i>P. bahamense</i> populations. The goal of this study was to examine toxin dynamics and associated molecular mechanisms in spatially and temporally distinct <i>P. bahamense</i> populations from the Indian River Lagoon, FL. <i>SxtA4</i> is a key gene required for toxin biosynthesis. <i>SxtA4</i> genotype analysis was performed on individual cells from multiple sites. Cell abundance, toxin quota cell^-1, and 2024-01-01T00:00:00Z2024 Jul2026-04-21T03:24:20.302Z2025-08-27T03:10:58.603ZS-EPMC112779793905742010.3390/md22070311