Balechina and the new genus Cucumeridinium gen. nov. (Dinophyceae), unarmored dinoflagellates with thick cell coverings

The genus Balechina (=subgenus Pachydinium ) was established for heterotrophic gymnodinioid dinoflagellates with a thick cell covering. The type species, B. pachydermata (= Gymnodinium pachyderm‐atum ), showed numerous fine longitudinal striae, whereas B. coerulea (= G. coeruleum ) showed ~24 prominent longitudinal surface ridges or furrows and a distinctive blue pigmentation. We have investigated the morphology and molecular phylogeny of these...