A new species and a new combination in Protoperidinium sect. Oceanica (Peridiniales, Dinophyceae) from Vietnamese waters
Creators: name: Phan, Luom
name: Krakhmalnyi, Maxim
name: Le, Ha
name: Tran, Van
name: Tran, Hue
name: Huynh, Ngoc Duyen
name: Darki, Behrouz
name: Krakhmalnyi, Aleksandr
Publisher: name: Zenodo
Year: 2024
Subjects: Protoperidinium vietnamicum sp. nov.
Vietnam
Dinoflagellata
Protoperidinium curvicorne comb. nov.
Hormuz Island

description: 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.
description: Funding provided by: Vietnam Academy of Science and TechnologyCrossref Funder Registry ID: https://ror.org/02wsd5p50Award Number: CSCL.17.01/22-23
description: 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, not including the cingular lists.




Depth (or height in some literature) (D) was measured in its widest part in lateral view, not including the cingular lists.




L/W ratio showing the variability in the cell size between Protoperidinium species section Oceanica.



Ecology and distribution:





Physical conditions such as temperature, salinity, and depth profile were measured at each sampling time using SeaBird 19 plus CTD (Sea-Bird Scientific, USA). Data from CTD were downloaded and processed using software from the manufacturer.




The GPS coordinates are collected at each station.




NA denotes missing values.



Comparison of the morphological biometrical characterizations:

The morphological characterizations of Protoperidinium species and the use of biometric terminology and abbreviations are as follows:





Apical horn: forms the apex of the cell and is formed by the apical plates.




Antapical horns: typically formed by antapical plates.




Cingulum: located approximately at the midpoint of the cell. When the cingulum is displaced, descending is the most common; the distal end is below the proximal end, which is always on the left side of the cell.




Sulcus: the longitudinal area on the ventral surface of the cell in Protoperidinium species, which is mainly in the ventral of the hypotheca.



The names of the thecal plates are abbreviated according to the Kofoid tabulation system as follows:





Intercalary plates (1a-3a) at epitheca do not touch the apex and the cingulum; the shape of the second anterior intercalary (2a) plate, such as quadra (four-sided), penta (five-sided), and hexa (six-sided).



Box plots:

Box plots were created by RStudio using the package "ggplot2" (Wickham, 2009). Wickham, H. (2009) Ggplot2: Elegant Graphics for Data Analysis. 2nd Edition, Springer, New York. https://doi.org/10.1007/978-0-387-98141-3.