| Abstract: | A new marine heterotrophic dinoflagellate species, Protoperidinium belizeanum sp. nov., from a coral reef‐mangrove pond was identified from scanning electron micrographs. Recognition of this new species was based on unique features of the thecal morphology, which included cell size and shape, presence of short and wide postcingular plates, sulcal architecture, antapical spines, and intricate thecal plate patterns of ridged hexagonal depressions. The thecal plate formula is as follows: Po, X, 4′, 3a, 7″, 4C (3+t), 6S, 5?, 2″″. Species association of P. be‐lizeanum sp. nov. within the genus Protoperidinium, its habitat, and associated dinoflagellates species are discussed. |
