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.