Ceratocorys mariaovidiorum sp. nov. (Gonyaulacales), a new dinoflagellate species previously reported as Protoceratium reticulatum

12 pages, 5 figures, 1 table.-- This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly citedThe family Ceratocoryaceae includes the genera Ceratocorys, Protoceratium, and Schuettiella, whose phylogenetic relationships are poorly known. Here, the new non-yessotoxin-producing species of the genus Ceratocorys, Ceratocorys mariaovidiorum sp. nov., previously reported as the toxic Protoceratium reticulatum, is described from examinations by light and scanning electron microscopy, molecular phylogeny, and toxin analyses. The species description is made from culture samples of strains CCMP1740 and CCMP404 from USA waters. Ceratocorys mariaovidiorum is globular and has thick and strongly reticulated plates with one pore within each reticule, just like P. reticulatum, but the key difference between the two species is the presence of five precingular plates in C. mariaovidiorum instead of six as in P. reticulatum. The thecal plate formula is Po, 40, 0a, 5″, 6c, ~7s, 5‴, 0p, 20000. The apical pore plate is oval with a k-shaped pore. The first apical plate is narrow with a ventral pore on the right anterior side; it contacts the apical pore plate and its contact with the anterior sulcal plate is slight or absent. The fourth precingular plate of other Gonyaulacales is absent. Ceratocorys mariaovidiorum may have small spines on the second antapical plate. A phylogenetic study based on internal transcribed spacer/5.8SrDNA supports the morphological classification of C. mariaovidiorum as a new species of Ceratocorys and in a different clade from P. reticulatumThe present study is a contribution of the Unidad Asociada “Microalgas Nocivas” (CSIC–IEO) that was carried out at the Instituto Espa~nol de Oceanograf ıa (IEO) in Vigo and funded by the CCVIEO project, the Spanish National Project CICAN (CGL2013-40671-R) and CIGUATROP Spanish project funded by Fundaci on Biodiversidad. This article will be part of the doctoral thesis of Pablo Salgado and is within the doctoral program “Marine Science, Technology and Management” (DO*MAR) of the University of Vigo. P. Salgado is a researcher at the Instituto de Fomento Pesquero (IFOP), which has provided financial support for his doctoral stay at the IEO in VigoPeer reviewe