Detection of bioluminescent dinoflagellates based on luciferase genes during the ‘blue tears’ season around the Matsu archipelago

Noctiluca scintillans is considered to be a bioluminescent bloom-forming species in the coastal water around the Matsu archipelago. To identify the bioluminescent dinoflagellates and their distributions around the Matsu archipelago, metatranscriptome and luciferase (lcf) gene sequencing were conducted from June 2016 to July 2017. Metatranscriptomes retrieved lcf genes mainly from Noctiluca and other bioluminescent dinoflagellates. This result demonstrates that lcf genes were actually expressed in multiple dinoflagellate species. An analysis of the lcf composition of dinoflagellates indicated that N. scintillans was the dominant bioluminescent species during May and July. In late summer, this dominance was replaced by other bioluminescent dinoflagellate species, such as Alexandrium affine and Ceratium fusus . No lcf gene from the known toxic bioluminescent dinoflagellates was obtained during the period of investigation. Our results suggest that N. scintillans is not the only dinoflagellate species producing bioluminescence around the Matsu archipelago.