Peridiniopsis quadridens (F.Stein) Bourrelly (1968: 9)

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 : 152-153

Peridiniopsis quadridens (F.Stein) Bourrelly (1968: 9) . Figure 11

Basionym: Peridinium quadridens Stein (1883: 11)

Synonym:

Glenodinium quadridens in J. Schiller (1935: 117)

Cell shape: Pentagonal, slightly compressed dorsoventrally, with bilateral symmetry in apical view.

Thecal characteristics: Tabulation, Po, 5ʹ, 1a, 7ʹʹ, 6C, 5S, 5ʹʹʹ, 2ʹʹʹʹ. Conical epitheca, longer than the hypotheca. The only anterior intercalary plate symmetrically located in the dorsal side ( Fig. 11B ). Rounded hypotheca, with spines.

Cingulum and sulcus: Cingulum slightly displaced, descendent. The sulcus penetrates slightly in the epitheca ( Fig. 11A ).

Locality: Guatapé reservoir North-west Colombia.

Comments: This is the first record of the species in Colombia. Measurements and detailed diagnostic characters were not possible to perform, due to the low number of specimens found. Identification was based on the presence of five apical plates and a single anterior intercalary plate in one empty theca.

World distribution: Europe, USA, and New Zealand ( Moestrup & Calado 2018).

Figures

FIGURE 11. Peridiniopsis quadridens. A. Epitheca plates, ventral view. B. Epitheca plates, dorsal view.