Datensatz

Zusammenfassung

A new peridinioid, cyst-producing dinoflagellate, Peridiniopsis amazonica spec. nov., is described from six Central Amazonian floodplain lakes of different lake water types (white, mixed and dystrophic black water lakes). It is the most common dinoflagellate and is dominant in acidic and circumneutral lakes lateral to Rio Negro and Rio Solimoes at low water levels, low nutrient supply and relatively high water temperatures. The large sized species is distinctive in its rhombic body shape, rigid theca, two prominent antapical spines and offset cingulum. The plate formula is: Po, X, 3', 1a, 6 '', 6c, 4s, 5''' 2''''. Peridiniopsis amazonica forms endogenous resting cysts with unornamented walls reflecting the shape of the vegetative cell. The period of high water level is spent in the cyst stage