Amphidoma parvula (Amphidomataceae), a new planktonic dinophyte from the Argentine Sea

TILLMAN U; GOTTSCHLING M; GUINDER VA; KROCK B

EUROPEAN JOURNAL OF PHYCOLOGY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2017

0967-0262

Amphidoma isan old though poorly studied thecate dinophyte taxa that has attractedattention recently as potential producers of azaspiracids, a group of lipophilic phycotoxins. Wedescribe a new species, Amphidoma parvulasp. nov., from the South Atlantic shelf off Argentina. With a Kofoidean thecal platepattern Po cp, x, 6´, 6´´, 6C, 5S, 6´´´, 2´´´´, the cultivated strain H-1E9 (ofwhich the type material of Am. parvulawas prepared) shared the characteristic plate arrangement of Amphidoma with six apical, precingularand postcingular plates. Amphidomaparvula differed from other species of Amphidomaby a characteristic combination regarding its small size (size range), ovoidshape, the length ratio between epitheca and hypotheca, and the length ration betweenapical and precingular plates. Other morphological details, such as the numberand arrangement of sulcal plates and the fine structure of the apical pore complex,support the close relationship between Amphidomaand Azadinium. However, Am. parvula lacked a ventral pore, acharacteristically structured pore found in all contemporary electronmicroscopy studies of Azadinium and Amphidoma. Using liquid chromatographycoupled tandem mass spectrometry, an extensive search for azaspiracids revealedthat Am. parvula did not produce AZA inmeasureable amounts. Molecular phylogenetics confirmed the systematic placementof Am. parvula in Amphidoma (as sister species of Amphidoma languida) and theAmphidomataceae.  With our study, weincrease the knowledge of Amphidomataceae biodiversity.