AUTHOR=Anschütz Anna-A. , Flynn Kevin J. , Mitra Aditee 

TITLE=Acquired Phototrophy and Its Implications for Bloom Dynamics of the Teleaulax-Mesodinium-Dinophysis-Complex

JOURNAL=Frontiers in Marine Science

VOLUME=8

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.799358

DOI=10.3389/fmars.2021.799358

ISSN=2296-7745

ABSTRACT=<p>The dinoflagellate <italic>Dinophysis</italic> is responsible for causing diarrhetic shellfish poisoning impacting shellfish aquaculture globally. <italic>Dinophysis</italic> species are invariably plastidic specialist non-constitutive mixoplankton (pSNCM), combining phagotrophy with acquired phototrophy. <italic>Dinophysis</italic> acquires phototrophy from another pSNCM, the ciliate <italic>Mesodinium</italic>, which in turn acquires phototrophy from cryptophytes within the <italic>Teleaulax-Plagioselmis-Geminigera</italic> clade. Despite this trophic linkage, the temporal dynamics of cryptophyte-<italic>Mesodinium-Dinophysis</italic> remain poorly understood. In this study, we present the first <italic>Teleaulax-Mesodinium-Dinophysis</italic> (TMD)-complex system dynamics model. Using this, we explored the dynamics of TMD interactions under different ecological settings. Temperature, nutrient load, mixed layer depth, and irradiance all greatly influenced the timing and magnitude of the TMD-complex interactions and, as a result, <italic>Dinophysis</italic> bloom duration and peak. Availability of <italic>Mesodinium</italic> and temporal matching of its growth to that of <italic>Dinophysis</italic> are also key biotic factors; the timing of <italic>Mesodinium</italic> availability impacts the potential of <italic>Dinophysis</italic> growth for up to 3 months. Integrating our TMD-complex model with a suitable hydrodynamic model could greatly improve our understanding of bloom formation and aid in forecasting harmful algal bloom (HAB) events. Future monitoring of <italic>Dinophysis</italic> would also be enhanced by the monitoring of the precursor prey species, <italic>Teleaulax</italic> and <italic>Mesodinium</italic>, which are rarely accorded the same effort as the HAB forming dinoflagellate.</p>