First record of the genus Togula (Gymnodiniales, Dinophyceae) and of the species T. jolla for the South-West Atlantic coastal waters

Abstract

In the framework of a phytoplankton and biotoxin monitoring program implemented since 2008 in marine coastal waters of the Buenos Aires Province (Argentina), a gymnodinioid, photosynthetic dinoflagellate was isolated from a sample collected in Santa Teresita, establishing the strain LPCc007. The strain was identified as belonging to the psammophilic genus Togula by light microscopy based on the following distinctive characters: morphology of the cell dorso-ventrally flattened, and course of the cingulum, highly asymmetric, descending, with its ends displaced by about one to two thirds of the total length of the cell and joined by an oblique intercingular groove. The comparative morphological analysis between the motile vegetative cells of the isolated strain and the three species of the genus described to date, did not reveal significant differences that would allow it to be determined at a specific level. Instead, the pattern of development of longitudinal grooves on the hypocone of cells about to undergo mitosis observed in strain LPCc007, perfectly agrees with that described for T. jolla as a differential character. The morphological identification was consistent with LSU rDNA (D1-D2) based phylogeny that showed the sequence aggregation in the T. jolla clade. This is the first report of the genus Togula and the species T. jolla from Argentina and the South-West Atlantic Ocean coastal waters.