An individual non‐motile (NM) cell was isolated from a surface sediment sample collected in Guangxi, China and subsequently established as a dinoflagellate strain in culture. The motile cells are 22.5–32.5 µm long and 20.0–30.0 µm wide, with a plate formula of Po, X, 4′, 3a, 7″, 6c, 5(?)s, 5″′, 2″″, fitting the description of Vulcanodinium rugosum . The Chinese strain shares 99.8%, 97.4% and 96.7% similarity (LSU sequence) wit...