Glochidinium, Bustamante-Gil & Boltovskoy & Rengefors & Tavera & Amat & Ramírez-Restrepo, 2021

Bustamante-Gil, Carolina, Boltovskoy, Andrés, Rengefors, Karin, Tavera, Rosaluz, Amat, Eduardo & Ramírez-Restrepo, Jhon J., 2021, Checklist, new records, and taxonomic annotations of freshwater thecate dinoflagellate (Dinophyceae) in Colombia, Phytotaxa 509 (2), pp. 135-167 : 143

Glochidinium penardiforme (Lindemann) Boltovskoy (1999: 99) . Figure 4

Basionym: Peridinium penardiforme Lindemann (1918: 126) .

Synonyms:

Peridinium penardiforme in Lindemann (1918: 126)

Peridinium penardiforme in Lindemann (1931: 703)

Peridinium penardiforme in Lefèvre (1932: 162)

Glenodinium penardiforme in Schiller (1937: 113)

Glenodinium penardiforme in Kiselev (1950: 142)

Peridinium penardiforme in Huber-Pestalozzi (1950: 247)

Glenodinium penardiforme in Thompson (1950: 295)

Peridiniopsis penardiforme in Bourrelly (1968: 8)

Peridiniopsis penardiforme in Popovský & Pfiester (1990: 197)

Peridinium penardiforme in Fukuyo et al. (1990: 132)

Peridiniopsis penardiforme Pollingher & Hickel (1991: 269)

Dimensions: L: 23–29 µm, Td: 17–21 µm.

Cell shape: Hearth-shaped contour in ventral view, dome-shaped epitheca and wider hypotheca, with the antapical end bi-lobulated. Oval contour in lateral view. Circular and very excavated cingulum dividing the theca in two equal parts. Compared to other small species the theca has thicker wall. ( Fig. 4A ).

Thecal characteristics: Tabulation, Po, X, 3ʹ, 1a, 6ʹʹ, 5ʹʹʹ, 2ʹʹʹʹ, 3c, 4S. There is a slight contact between the 2ʹ and 4ʹ plates by the SAS suture ( Fig. 4B ). The inner edges of the apical 2ʹ and 4ʹ form two smooth parallel lips bordering the apical pore complex (APC, Fig. 4B ). In ventral or dorsal view these appear as two small apical protrusions.

Cingulum and sulcus: Cingulum consisting of three plates. Unlike most Peridiniales , the distal end of the cingulum is in contact not only with the Sd plate, but also with the Sa plate ( Fig. 4D ). Four sulcal plates. The Sa plate penetrates slightly in the epitheca and touch the 3C plate ( Figs. 4C–4D ). The Sd plate is in contact with 3C plate too. Both, the Sd and Ss plates, are elongated, being the last one covered by the fin of the Sd plate ( Fig. 4D ). The Sp plate is the smallest, triangular, displaced to the left half of the sulcus ( Fig. 4D ).

Localities: El Pozuelo, Pijiño, and Zapatosa swamps in North Colombia.

Comments: The specimens found are smaller than the description by Lindemann (1918) and Cavalcante et al. (2017) and agree with the tabulation and general shape of that described by ( Boltovskoy 1999b). However, in the specimens of Colombia, the crescent moon-shaped fin of the Sd plate is smaller than those described in Cavalcante et al. (2017), but larger than that described by Boltovskoy (1999b), covering almost completely the Ss plate and nearly in contact with the 1ʹʹʹʹ plate ( Fig. 4D ). This is the first record of both the genus and the species in Colombia.

World distribution: Europe, Israel, Japan, USA. In South America in Argentina, Brazil, and Uruguay ( Boltovskoy 1999b; Moestrup & Calado 2018). In Mexico, a specimen of this genus was reported as Peridinium sp. ( Esqueda-Lara et al. 2016).

Figures

FIGURE 4: Morphology of Glochidinium penardiforme. A. LM ventral view. B. SEM ventro-apical view. C. SEM ventral view. D. Sulcus. Bar=5 µm.