Original Research ARTICLE
Association of the toxigenic dinoflagellate Alexandrium ostenfeldii with spirolide accumulation in cultured mussels (Mytilus galloprovincialis) from northwest Mexico
- 1Ensenada Center for Scientific Research and Higher Education (CICESE), Mexico
- 2Departamento de Biotecnología Marina, Mexico
- 3Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada, Mexico
- 4Centro de Investigacións Mariñas (CIMA), Spain
- 5Unidad de Ciencias del Agua, Centro de Investigación Científica de Yucatán, Mexico
- 6Alfred Wegener Institut Helmholtz Zentrum für Polar und Meeresforschung, Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ), Germany
Spirolides are polyether cyclic imines considered as “fast acting toxins”. Long term human health consequences of spirolide ingestion are uncertain, and hence regulatory limits for human consumption have not been established. Nevertheless, monitoring these toxins in shellfish is essential because they can interfere with detection by mouse bioassay of lipophilic regulated toxins. Todos Santos Bay (TSB), in the northeast of the Baja California Peninsula, is an important shellfish cultivation and fish-farming area in Mexico. The toxin analog 13-desmethyl spirolide C has been reported in cultivated mussels (Mytilus galloprovincialis) from TSB, but the causative species associated with accumulation of this toxin has not been previously identified. We assessed the occurrence of Alexandrium ostenfeldii, the unique known producer of spirolides, by inverted light microscopy and by PCR with species-specific oligonucleotides designed for the ITS and 18S rDNA. We determined the presence and abundance of this species at the surface and at the thermocline from samples collected over two annual sampling periods (2013 - 2014 and 2016 – 2017). During the 2013-2014 period, A. ostenfeldii was found in 50% of the samples analyzed by light microscopy. The highest cell abundance (about 3.6 x 103 cells L-1) occurred in October 2013. During 2016 – 2017 the dinoflagellate was present in low cell abundances (<5 x 102 cells L-1) and was detected in only 20.9% of the samples. Cells of this species were usually found when sea surface temperature ranged from 17 to 20 °C. We also evaluated spirolide accumulated in cultivated mussels from TSB by tandem mass spectrometry (LC-MS/MS). The only spirolide detected was 13-desmethyl spirolide C, found mainly during the 2013-2014 sampling period, with the highest concentration (1.05 μg kg-1) in June 2014. During winter, toxin concentration was at or below the detection limit. During 2016-2017, spirolides were below the detection limit, coinciding with the absence of the causative species. Cell abundance of A. ostenfeldii and spirolide concentration in mussels did not present a clear correlation. This study represents the first record of A. ostenfeldii in TSB and provides evidence that this species is the primary origin of spirolides accumulated in mussels.
Keywords: Polyether toxins, 13-Desmethyl spirolide C, LC-MS/MS, Marine dinoflagellates, Harmful algal blooms (HAB), Mediterranean mussel
Received: 01 Sep 2018;
Accepted: 04 Dec 2018.
Edited by:Marius N. Müller, Federal University of Pernambuco, Brazil
Reviewed by:Mariângela Menezes, Universidade Federal do Rio de Janeiro, Brazil
Mohamed Laabir, Université de Montpellier, France
Copyright: © 2018 Paredes-Banda, Garcia-Mendoza, Ponce-Rivas, Blanco, Almazán-Becerril, Galindo-Sánchez and Cembella. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Ernesto Garcia-Mendoza, Ensenada Center for Scientific Research and Higher Education (CICESE), Ensenada, Mexico, firstname.lastname@example.org