Frontonia angusta angusta Foissner, Berger & Agatha, 2002

Kizildag, Sibel & Yildiz, Ismail, 2019, Morphology and molecular phylogeny of four Frontonia species from Turkey (Protista, Ciliophora), Zootaxa 4609 (3), pp. 548-564 : 555-560

Frontonia angusta angusta Foissner, Berger & Agatha, 2002

Frontonia acuminata (Ehrenberg, 1833) Bütschli, 1889

Frontonia acuminata var. angusta Kahl, 1931

Frontonia angusta Kahl, 1931 — Foissner, Berger & Kohmann, 1994 Frontonia angusta angusta Foissner, Berger & Agatha, 2002

Description of the Turkish population: Size about 130–220 × 50–80 µm, but usually about 170 × 70 µm in size. Body outline is elongated oval with a slightly narrowed posterior half, dorso-ventrally compressed about 3:1 ( Table 1 ; Figs. 5 a–e; 6a–e). Single oval macronucleus, 20–50 × 10–30 µm in size and located mid body. Micronucleus 5–8 µm in diameter, mostly globular rarely oval in shape, and located in an indentation of the macronucleus ( Table 1 ; Figs. 5a ; 6a, f ). Single contractile vacuole without a collecting channel located mid body, single excretory pore lo- cated on the right dorso-lateral of the cell ( Figs. 5–c ; 6a, c, d, g ). The shape, size, and arrangement of the extrusomes are similar to the previous species. Cytoplasm colorless, food vacuoles contain diatoms, algae, and bacteria ( Figs. 5a ; 6a, b, f ). Somatic cilia 8–9 µm long and arranged in 80–130 meridional rows of kinetosomes, form a suture in the ventral midline of the cell ( Fig. 5g ). Postoral kineties counted as 4–6 ( Table 1 ). Oral apparatus typical of the genus, about 1/5–1/6 of the body length, located in the anterior 1/3 of the cell. Three vestibular kineties, 3 peniculus, each consisting of 4–5 rows of kinetosomes. Paroral membrane is in a single row and surrounds the right side of the buccal cavity ( Figs. 5d, f ; 6e, h ).

Frontonia anatolica Yıldız & Şenler, 2013

Description of the Turkish population: Body size 100–135 × 50–70 µm, usually about 120 × 60 µm in vivo, ratio of length to width about 1:2, elliptical outline when viewed from the ventral or dorsal side, dorso-ventrally compressed about 2:1 ( Table 1 ; Figs. 7a–e, 8a–e). Single macronucleus is usually oval, rarely globular, or elliptical, about 30 × 20 µm in size. Micronucleus is ellipsoidal to globular, located in an indentation of the macronucleus, about 6 × 5 µm in size ( Table 1 ; Figs. 7a; 8a, b, d, g, h). Two contractile vacuoles, each with long collecting canals,

The topologies of the ML and BI trees were similar; therefore, the topology of the ML tree was shown with support values from both algorithms on the branches ( Fig. 9 ). Peniculia formed a fully supported clade in the class Oligohymenophorea (BI/ML, 1.00, 100%). Within the Peniculia clade, the family Lembadionidae (clade C) was basal to the other peniculines included in the analyses (BI/ML, 1.00, 100%) (clades A and B). Clades A and B included 4 families: Stokesiidae , Frontoniidae , Maritujidae , and Parameciidae . Frontonia species were located in both clades A and B. Clade A was formed by group A1 ( Stokesia vernalis , Disematostoma minor , Disematostoma sp., Marituja cf. caudate, Marituja sp.) and group A2 ( Frontonia terricola and F. acuminata ) (BI/ML, 1.00, 100%). Clade B was separated into 2 subclades and consisted of 5 groups. The first subclade was formed by groups B1 and B2 and contained only Frontonia species. The second subclade consisted of group B3 ( F. anatolica , F. didieri , F. ocularis , F. elegans , F. pusilla ), group B4 ( Apofrontonia dohrni ), and group B5 ( Paramecium spp.). In the phylogenetic tree, F. acuminata and F. terricola were included in group A2, and were more closely related the members of the genera Stokesia , Disematostoma , and Marituja than the other Frontonia species. Similarly, F. anatolica ( MG456578 , MG456581 ), F. didieri , F. ocularis , F. elegans , and F. pusilla were more closely related the species of the genera Apofrontonia and Paramecium than the other Frontonia members.

Figures

FIGURE 5. F. angusta angusta from live material (a–c, g) and after silver staining (d–f). Ventral-lateral view (a–c). Infraciliatures of the ventral (d), dorsal (e) and buccal (f) areas. Part of a pellicle, to show extrusomes (g). Abbreviations: AL: argentophilic line; C: Cilia; CV: contractile vacuole; D: diatom; E: extrusome; EP: excretory pore; Ma: macronucleus; Mi: micronucleus; OA: oral apparatus; P1–P3: peniculi 1, 2, and 3; PK: postoral kineties (arrowheads in f); PM: paroral membrane; PoS: postoral suture; PrS: preoral suture; Cyp: cytopyge; VK1–3: vestibular kineties 1, 2, and 3. Arrowheads mark postoral kineties. Scale bar = 70 µm.

FIGURE 6. F. angusta angusta from live material (a–d) and after silver staining (e–i). Ventral views (e). Silver nitrate staining (f). Silver carbonate staining. Dorsal view (g). Silver nitrate staining of the somatic ciliature and oral ciliature (h). View of an argyrome part (i). Abbreviations: CV: contractile vacuole; D: diatom; E: extrusome; EP: excretory pore; FA: filamentous algae; Ma: macronucleus; Mi: micronucleus; OA: oral apparatus; P1–P3: peniculi 1, 2, and 3; PM: paroral membrane; PoS: postoral suture; PrS: preoral suture; VK1–3: vestibular kineties 1, 2, and 3. Scale bar = 60 µm.

FIGURE 9. BI and ML analyses based on SSU rDNA gene sequences. The sequences of Frontonia populations in study are indicated in bold. Numbers at the nodes indicate the BI posterior probability and the ML bootstrap values (BI/ML). Nodes that were fully supported (100% ML, 1.00 BI) are represented by solid circles. A dash indicates a value less than 0.50 (BI) or 50% (ML). Bar, 8 substitutions per 100 nucleotide positions.