Lingulodinium polyedra (F. Stein) Dodge

Lewis, Jane, Taylor, Joe D., Neale, Klaire & Leroy, Suzanne A. G., 2018, Expanding known dinoflagellate distributions: investigations of slurry cultures from Caspian Sea sediment, Botanica Marina (Warsaw, Poland) 61 (1), pp. 21-31 : 27

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.

Figures

Figures 2–31: Light micrographs of Caspian Sea dinoflagellates grown in culture from sediments. (2–6) Gonyaulax baltica, culture CS-ST1-005. (2) Lateral view of cell showing cingulum offset. (3) Dorsal view of cell showing general shape and wide cingulum. (4) Antapical view of cell showing broad sulcus. (5) Ecdysed cell showing antapical spines. (6) Hypotheca of cell showing plate reticulation, smooth sulcus and intra plate growth bands. (7–10) Gonyaulax sp., culture CS-ST2-001. (7) Lateral view of cell showing general shape, cingulum offset, apical horn and antapical spine. (8) Ventral view of cell showing broad offset cingulum. (9) Dorsal view of cell in outline showing pronounced apical horn and definite shoulders. (10) Ecdysed theca showing solid antapical spine and heavy plate reticulation. (11–14) Gymnodinium aureolum. (11–13) Culture CS-ST7-009. (14) Culture A3. (11) Cell showing overall shape, central nucleus and radiating chloroplasts. (12) Ventral view of cell showing sulcal-cingulum arrangement. (13) Dorsal view of cell. (14) Cells in duplet. (15–20) Kryptoperidinium foliaceum. (15 and 19) Culture CS-ST1-007. (16 and 18) Culture CS-ST1-001. (17 and 20) Culture A6. (15) Ventral view of cell showing leaf-like curvature, central nucleus, median cingulum and eyespot. (16) Lateral view of cell showing dorsoventral flattening and eyespot. (17) Theca stained with trypan blue. (18) Cysts in ventral view. (19) Cyst in lateral view. (20) Cysts in mucoid capsule. (21–25) Lingulodinium polyedra. (21 and 23) Culture CS-ST1-002. (22) Culture CS-ST1-004. (25) Culture CS-ST1-003. (21) Ventral view of cell showing cingulum offset and first apical plate. (22) Dorsal view of cell showing horse-shoe shaped nucleus. (23) Ecdysed hypotheca showing distinctive polyhedral shape and plate reticulation. (24) Squashed cell showing thecal plates. (25) Cyst from Station 1 sediment. (26–28) Scrippsiella acuminata. (26) Culture CS-ST2-006. (27–28) Culture D10. (26) Outline view of cell. (27) Outline view of cell. (28) Cyst formed in culture. (29–30) Woloszynskia sp. (29) Culture D3 showing cell with eyespot. (30) Cell showing general outline from culture D4. (31) Impagidinium caspienense from palynological preparation (core CS03/1 at 32 cm) showing archeopyle. Scale bars = 10 µm.