A new species and a new combination in Protoperidinium sect. Oceanica (Peridiniales, Dinophyceae) from Vietnamese waters

In this study, we described and illustrated details of a new species, Protoperidinium vietnamicum sp. nov., from Vietnamese coastal waters and Protoperidinium curvicorne (Böhm) comb. Nov. is proposed as a new combination. Each cell's size range (length, width, and depth) was measured, and the morphological features of both species described here and selected related species in the Oceanica section were compared. In addition, the ecology and distribution of both species were given., Sampling
These datasets were created from phytoplankton samples collected with vertical net hauls (mesh size – 25 µm and net diameter – 30 cm) at locations along Vietnamese coastal water, proven from associated projects in Vietnam.
Analyses
Take photographs:
Cells were observed by light microscopy (LM) and scanning electron microscopy (SEM). LM was performed using a Leica DMLB (Solms, Germany), and a digital camera DP71 (Olympus) was used for micro-photography. SEM was scanned on the Hitachi S4800 Field-Emission SEM (Hitachi Manufacturing Institute) at a voltage of 10.0 kV and a working distance of 8.3–9.2 mm. 
Biometric analyses:
Morphological measurements of cells from each photographed cell were carried out by light microscopy using imaging software (Standard cellSens ver. 3.1.1, Olympus, Tokyo, Japan).

The length (L) of the cell was measured from the epitheca's apex to the hypotheca's antapex.

The width (W) of the cell was measured directly in front of the cingulum or behind it,..., , Title dataset: A new species and a new combination in *Protoperidinium* sect. Oceanica (Peridiniales, Dinophyceae) from Vietnamese waters

Give a brief summary of dataset contents, contextualized in experimental procedures and results.

**Supplementary Figure S1.** Box plots of morphological biometric variation of thirteen *Protoperidinium* species belonging to section *Oceanica* in Vietnamese waters. Box diagrams show mean values (horizontal lines) and standard deviation bars. Described in Methods: Biometric analyses and box plots.

**Supplementary Table S1.** Ecology and distribution of *Protoperidinium vietnamicum* sp. nov. and *P. curvicorne* (Böhm) comb. nov. in Vietnamese and Iranian waters. Described in Methods: Ecology and distribution

**Supplemental Table S2.** Summarise the morphological biometrical characterizations of *Protoperidinium* species belonging to the section *Ocenica *from Vietnamese waters. Described in Methods: Comparison of the morphological biometrical chara...