Lingulodinium polyedra (F. Stein) Dodge

(Figures 21–25)

Cells were brown in colour (Figure 21), 28–45 µm long and 28–45 µm wide. Cells showed a characteristic angular outline with flattened hypotheca and angular epitheca with a very small apical horn (Figure 22). Cingulum was median and offset by one cingulum width (Figure 21). Strong thecal plates with circular ridges around the trichocyst pores and ridges along plate boundaries (Figures 23 and 24). The nucleus was U-shaped and lying across the middle of the cell (Figure 22). Cysts were found in the sediment samples examined (Figure 25), and various spine lengths were noted, probably driven by the low salinities in the Caspian, as has been recorded by Mertens et al. (2012). Cultures of Lingulodinium were the most numerous in this study indicating their common occurrence in the sediment as well as ease of culturing.