Euglena (Ehrenberg, 1830)

Juráň, Josef, 2017, The checklist of photosynthetic euglenoids (order Euglenales) of the Czech Republic: ecology, taxonomy, distribution, Phytotaxa 317 (1), pp. 1-16 : 4-5

Euglena from section Amastigate Elenkin [ Bot. Mater. 3(9): 144. 1924]

Ettl (1955) reported in his diploma thesis the species Euglena terrestris from wet soil humidified by spring near Březová (Svitavy district, Czech Republic) with following description: “Cells are cylindrical with rounded apical and antapical ends, in cross section round, metabolical. Periplast gently spirally grooved (grooves are visible after the fixation), 7–8 grooves in 10 μm. Flagella absent, cell moves by vermiform movement. Chloroplasts numerous, 12 μm large, plate-like, without pyrenoids. Stigma quite large, bright red. Nucleus in first third of the cell. Paramylon in form of rounded plates, 5–6 μm in diameter. Hematochrome in form of numerous spots which are scattered across the cell, of the size of stigma. Reproduction by division in resting stage.” No illustration was included in the description.

This taxon belongs to the Amastigate group designed by Elenkin (1924) and is characterized especially by the absence of flagella. Based on described morphological features, most similar Euglena taxon already described is E. fenestrata , which differs from the taxon described by Ettl due to the absence of hematochrome spots in the cell. Using the hematochrome presence as a taxonomic character is uncertain due to the alternation of its presence in the cell depending on environmental conditions ( Buetow 1968). For that reason, Ettl’s taxon is listed in this work only as a note because it would be necessary to make further observation for validation of this taxon.

Trachelomonas hexangulata f. polonica (M. Koczwara) T.G. Popova [Fl. Spor. Rast. SSSR 8: 184. 1966] Basionym: Trachelomonas polonica M. Koczwara [Kosmos (Lwów) 40: 260, 273, pl. I: fig. 1. 1917] non T. polonica R. Dreżepolski

[Rozp. i Wiad. Muz. Dzieduszyckich (Lwów) 7/8: 7, 16, pl. I: fig. 28. 1923] non T. polonica R. Dreżepolski [Kosmos (Lwów) 50:

220, 263, fig. 42. 1925] Synonym: Trachelomonas cylindroconica R. Dvořák [Sdělení o nových druzích moravských řas: 8, no fig. 1920]

Trachelomonas cylindroconica was described by Dvořák (1920) from the discharge of a small pond near Studenec (Třebíč district, Czech Republic). Species was described without an illustration, only with the following description: “Lorica cylindrical, trapering at the apical and antapical end, smooth, 27–30 μm long and 13–16 μm wide, collar cylindrical, 5 μm high.”

Based on Dvořák’s description, it could be inferred that this taxon is some form of Trachelomonas hexangulata , probably with more elevated collar than in typical form of T. hexangulata ( Starmach, 1983) . It is probable that the reported species is identical with T. hexangulata f. polonica (loricas 28–39 μm long, 11,5–17 μm wide, height of collar 2–3,5–5 μm) described by Popova (1966).

Trachelomonas caudata (C.G. Ehrenberg) F. Stein [Org. Infusionsthiere III, 1: legend to pl. XXII: fig. 39, 40. 1878] Bas.: Chaetoglena caudata C.G. Ehrenberg [Ber. K. Akad. Wiss. Berlin 1840: 199. 1840] Syn.: Trachelomonas caudata var. glabra R. Dvořák [Sdělení o nových druzích moravských řas: 8, no fig. 1920], T. caudata var. glabra

Dvořák sensu Z. Cyrus [Věstník českého musea v Žatci 23: 10, no fig. 1934], T. swirenkoi var. punctata B.V. Skvortsov [Zhurn.

Mikrobiol. 4: 73, pl. V: fig. 2. 1917]

Trachelomonas caudata var. glabra comes from the same locality as Trachelomonas cylindroconia and the description is based only on the lorica surface: “With lorica without spines and perfectly smooth.” After this publication, Cyrus (1934) reported probably the same taxon in a small pool near Kouňov (Rakovník district, Czech Republic) with more detailed description: “Lorica elongated obovate, smooth colourless, with short straight caudal projection. Collar serrated at the edge. Flagella of the length of lorica. Dimensions of lorica 52 x 21 μm.” Unfortunately, neither of these findings are documented by drawings.

Pringsheim (1953) and Singh (1956a,b) showed that the morphology of Trachelomonas’ lorica depends on the stage of life cycle and environmental conditions. Detailed study of the Trachelomonas caudata complex was made by Wołowski et al. (2016). With this information, it could be inferred that the taxa which Dvořák and Cyrus described were young cells of Trachelomonas caudata without well-developed ornamentation and with incomplete incrustation of loricas. That could explain their smooth surface and hyaline nature of the lorica.

Some species from the genus Euglena ( E. acus , E. oxyuris , E. spirogyra and E. tripteris ) were moved to the genus Lepocinclis by Marin et al. (2003). Some new combination of varieties of these taxa was made by Ciugulea & Triemer (2010) and Kapustin (2011). To clarify the taxonomic situation of the similar taxa placed in the following checklist, new combinations are made within this study: