Parvodinium elpatiewskyi (Ostenfeld) Kretschmann,Zerdoner & Gottschling (2020)

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 : 150-152

Parvodinium elpatiewskyi (Ostenfeld) Kretschmann,Zerdoner & Gottschling (2020) . Figures 9–10

Basionym: Peridinium umbonatum var. elpatiewskyi Ostenfeld (1907: 391)

Synonyms:

Peridinium elpatiewskyi in Lemmermann (1910: 670)

Peridinium pygmaeum in Lindemann (1919: 232)

Glenodinium elpatiewskyi in J. Schiller (1935: 115)

Dimensions: L: 26–46 µm, Td: 23–33 µm

Cell shape: Ovoid or pentagonal with protruding apex ( Fig. 9A ). The plates have marginal ridges of different size. The hypothecal plates are bordered by spines. The cingular lists slightly prominent, presents crenulated margins, and are reinforced by distal ribs ( Fig. 10E ).

Thecal characteristics: Tabulation, Po, X, 4ʹ, 7ʹʹ, 6C, 5S, 5ʹʹʹ, 2ʹʹʹʹ. The epitheca is taller than the hypotheca. The plates 2ʹ, 3ʹ, 4ʹ are in contact with the apical pore (Po), the plate 1ʹ is in contact with the apical groove platelet (X). Without intercalary plates ( Figs. 9C and 10C ). The apical pore plate (Po) is ornamented with nodules ( Fig. 10F ) and has a circular circular plug that closes the apical pore (10A and 10D). The apical pore complex is surrounded by a continuous strip ( Fig. 10D ), formed by the marginal ridges of the plates 2ʹ, 3ʹ and 4ʹ ( Fig. 9D ). The hypotheca consists of 7 plates, five post-cingular and two antapical. It has several spines placed on the edges of plates 1ʹʹʹ, 4ʹʹʹ, 5ʹʹʹ and 1ʹʹʹʹ, but the most remarkable in length and thickness are those located in the zones where the plate 1ʹʹʹʹ is in contact with the plate Sp ( Figs. 10B and 10E ).

Cingulum and sulcus: Cingulum is circular or slightly descendent ( Fig. 9B ) and consists of 6 plates. The sulcus is formed by 5 plates, penetrates slightly into the epitheca, and reaches the antapex. The right sulcal plate (Sd) is elongated longitudinally and on the left border has a less ornamented fin that almost totally covers the left and medial sulcal plates ( Fig. 10E ). The Sd plate is in contact with the 2ʹʹʹʹ plate through its posterior edge ( Figs. 10A and 10B ).

Ornamentation: The surface of the plates is covered with small nodules arranged in rows that form a reticulum; in addition, there are nodules not associated with the rows ( Fig. 10D ). The reticulum is more noticeable on the main plates and in older specimens. Some specimens present wide intercalary bands ( Fig. 10E ). The plates are perforated by pores with slightly raised edges, located on the intersections of the network. The pores are distributed irregularly on the plates surface, but near the cingular edges of the adcingular plates they are arranged in rows.

Locality: Piedras Blancas reservoir in North-west Colombia.

Comments: Our material agreed with those described in previous studies ( Ascencio et al. 2015; Carty 2014; Moestrup & Calado 2018; Ostenfeld 1907). However, in the specimens studied here, the fin of the Sd plate almost totally covers the Sm and Ss plates ( Fig. 10E ). This is the first record of the species in Colombia.

World distribution: Wide distribution in Europe, Asia, USA ( Moestrup & Calado 2018), and Mexico ( Figueroa Torres & Moreno-Ruiz 2003). In South America it has been reported in ( Cavalcante et al. 2017) and Chile ( Ascencio et al. 2015) as Peridiniopsis elpatiewskyi .

Figures

FIGURE 9. LM view of Parvodinium elpatiewskyi. A. Dorsal view. B. Ventral view. C Dorsal view. D. Apical view. Bar=10µm.

FIGURE 10. SEM view of Parvodinium elpatiewskyi. A. Ventral view, bar=5µm. B. Spines on the antapical zone. C. Dorsal view. D. Sutural bands. E. Sulcus. F. Apical pore. bar=5µm.