Sinophysis verruculosasp. nov. (Dinophysiales, Dinophyceae), a new sand-dwelling dinoflagellate from South Brittany, northwestern France

Abstract

AbstractA new species of a marine sand-dwelling dinoflagellate in the genusSinophysisis described from South Brittany, France using both light and scanning electron microscopy. Cells ofSinophysis verruculosasp. nov. are oval to subcircular, slightly bulging dorsally and flattened laterally, with no chloroplasts, ranging from 52.2 to 57.8 μm in length, and 43.2 to 51.0 μm in width. The epitheca is small and tilted back to the dorsal part of the cell. At least three major plates and smaller platelets form the epitheca, but the exact number cannot be ascertained due to their reduced size and the presence of a projection hiding the sutures. Four cingular and four hypothecal plates, two large lateral and two small ventral plates are present. The sulcus is bordered by lists supported by hypothecal plates and extends less than two-thirds of the total length of the hypotheca. The most distinctive feature ofS. verruculosais the minute verrucose ornamentation covering the thecal surface, which contrasts with the smooth and areolate ornamentation of temperate and tropical species, respectively.