AUTHOR=Lee Moo Joon , Hwang Yeong Jong , Choi Yong Bum , Yoo Yeong Du 

TITLE=Grazing impact of the calanoid copepods Acartia spp. on the toxic dinoflagellate Alexandrium pseudogonyaulax in the western coastal waters of Korea

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1400343

DOI=10.3389/fmicb.2024.1400343

ISSN=1664-302X

ABSTRACT=<p>Marine dinoflagellate species in the genus <italic>Alexandrium</italic> are well known to produce paralytic shellfish poison as well as common coastal species with cosmopolitan distribution. However, few studies on the feeding of copepods on <italic>Alexandrium</italic> species have been conducted. The toxic dinoflagellate <italic>Alexandrium pseudogonyaulax</italic> contains goniodomin A and causes red tides in many countries. To investigate the relationship between the toxic dinoflagellate <italic>A. pseudogonyaulax</italic> and the calanoid copepods <italic>Acartia</italic> spp., we quantified the ingestion rates of <italic>Acartia</italic> spp. feeding on <italic>A. pseudogonyaulax</italic> as a function of prey concentration. Additionally, we estimated grazing coefficients by integrating data from field observations of <italic>Acartia</italic> spp. and coexisting <italic>A. pseudogonyaulax</italic> with laboratory measurements of ingestion rates obtained during this investigation. Furthermore, we compared the ingestion rates of <italic>Acartia</italic> spp. and other predators feeding on <italic>Alexandrium</italic> species as previously reported. The ingestion rates of <italic>Acartia</italic> spp. on <italic>A. pseudogonyaulax</italic> increased continuously with increasing mean prey concentration. The highest values among the ingestion rate of <italic>Acartia</italic> spp. feeding on <italic>A</italic>. <italic>pseudogonyaulax</italic> was 3,407 cells predator<sup>−1</sup> d<sup>−1</sup> (4,872 ng C predator<sup>−1</sup> d<sup>−1</sup>) at the given prey concentration. The calculated grazing coefficients for <italic>Acartia</italic> spp. on <italic>A. pseudogonyaulax</italic> in Shiwha Bay, Korea, were up to 0.073 d<sup>−1</sup>. The results of this study suggest that <italic>A. pseudogonyaulax</italic> may decrease or maintain the population of <italic>Acartia</italic> spp. in marine food webs.</p>