Morphological versus molecular delimitation of ciliate species: a case study of the family Clevelandellidae (Protista, Ciliophora, Armophorea) Author Pecina, Lukáš 8B83834D-884C-448A-A0CD-5A1FB9A3BB8C Department of Zoology, Comenius University in Bratislava, 842 15 Bratislava, Slovakia. pecinalukas1@gmail.com Author Vďačný, Peter 47A28E80-E04F-40C4-93A3-F7F685C9533A Department of Zoology, Comenius University in Bratislava, 842 15 Bratislava, Slovakia. peter.vdacny@uniba.sk text European Journal of Taxonomy 2020 2020-08-06 697 1 46 journal article 21346 10.5852/ejt.2020.697 58523d91-e809-474b-b5c8-a9c1d64ad17c 3978463 8962B6E6-B278-4EF5-9E62-3E858726E2F2 Clevelandella hastula ( Kidder, 1937 ) Figs 4–5 Description of Vietnamese population Size in vivo about 75–105 × 25–35 μm, usually 90 × 30 μm, as calculated from some in vivo measurements and morphometric data; length:width ratio ranging from 2.6:1 to 3.5: 1 in protargol preparations ( Table 2 ). Body spear-shaped, widest at mid-portion, i.e., about at level of contractile vacuole. Anterior end pointed; posterior body portion differentiated into a conspicuous, long peristomial projection; left side distinctly curved at level of proximal end of adoral zone of membranelles and hence forming a lobe above the base of peristomial projection ( Figs 4 A–N, 5A–H). Macronucleus located in anterior second fourth of body; ellipsoidal, with a length:width ratio of 1.3–1.7: 1 in protargol preparations; 15–23 × 11–15 μm in size after protargol impregnation; filled with innumerable globular structures (presumably nucleoli) 0.7–1.8 μm in diameter after protargol impregnation, well observable in vivo and in some protargol preparations. Karyophore absent. Micronucleus invariably attached to anterior side of macronucleus; almost globular to broadly ellipsoidal with a length:width ratio of 1.0–1.7:1; about 4–6 × 3–4 μm in size after protargol impregnation ( Table 2 ; Figs 4 A–L, 5B–F). Contractile vacuole just above base of peristomal projection near left body margin, i.e., at level of proximal end of peristomial funnel ( Fig. 4A, L ). Cortex flexible, no cortical granules recognizable. Cytoplasm colorless; finely granulated; refractile bodies concentrated in cytoplasm anteriorly to macronucleus, recognizable in vivo and after protargol impregnation; cytoplasm posterior to macronucleus contains some free (symbiotic?) bacteria and/or archaea and food vacuoles about 2.5–4.0 μm across with prey prokaryotes ( Figs 4A , 5 B–F). Swims slowly; dies quickly on microscope slides, possibly due to presence of oxygen; body shape changes in dying and strongly squeezed cells, i.e., left margin loses a small notch at level of the base of peristomial projection ( Fig. 5 F–H). Table 2. Morphometric data on Clevelandella hastula ( Kidder, 1937 ) from Vietnam.

Characteristica	Mean	M	SD	SE	CO	Min	Max	n
Body, length	78.4	79.5	7.3	2.3	9.3	66.0	87.0	10
Body, maximum width	26.8	27.5	2.6	0.8	9.8	23.0	30.0	10
Body, length:width ratio	2.9	3.0	0.3	0.1	8.8	2.6	3.5	10
Peristomial projection, length	30.0	30.5	3.9	1.2	13.1	23.0	34.0	10
Peristomial projection, width	11.3	11.5	1.8	0.6	15.6	9.0	15.0	10
Peristomial projection, % of body length	38.2	38.6	3.0	0.9	7.8	33.7	41.4	10
Peristomial opening, length	13.2	13.5	1.6	0.5	12.3	11.0	15.0	10
Peristomial opening, width	10.2	10.0	1.2	0.4	12.1	9.0	12.0	10
Peristomial opening, % of body length	16.8	17.0	1.1	0.4	6.7	15.2	19.0	10
Adoral zone of membranelles, length	33.9	34.5	1.9	0.6	5.6	30.0	36.0	10
Adoral zone of membranelles, % of body length	43.6	42.8	4.5	1.4	10.3	35.7	50.0	10
Anterior body end to macronucleus, distance	14.4	15.0	2.3	0.7	15.8	11.0	17.0	10
Posterior body end to macronucleus, distance	48.7	50.5	4.6	1.5	9.5	40.0	53.0	10
Macronucleus, length	18.2	18.0	2.6	0.8	14.1	15.0	23.0	10
Macronucleus, width	12.5	12.0	1.3	0.4	10.2	11.0	15.0	10
Macronucleus, length:width ratio	1.5	1.4	0.1	0.0	8.4	1.3	1.7	10
Macronucleus, number	1.0	1.0	0.0	0.0	0.0	1.0	1.0	10
Micronucleus, length	5.0	5.0	0.6	0.3	12.6	4.0	6.0	6
Micronucleus, width	3.8	4.0	0.4	0.2	10.6	3.0	4.0	6
Micronucleus, length:width ratio	1.3	1.3	0.2	0.1	17.6	1.0	1.7	6
Micronucleus, number	1.0	1.0	0.0	0.0	0.0	1.0	1.0	10
Adoral membranelles, number	32.3	32.0	1.6	0.5	5.1	30.0	35.0	10

a Data based on mounted, protargol-impregnated, and randomly selected specimens. Measurements in µm. Somatic ciliature holotrichous; cilia about 4.0–6.0 μm long in vivo and very narrowly arranged. Approximately 80 ciliary rows narrowly spaced over entire body surface and about 25 ciliary rows running onto peristomial projection. Peristomial ciliary rows in a form of strongly oblique lines in ventral view, while in a form of shallow arcs in dorsal view ( Figs 4 M–N, 5G–H). Almost all body ciliary rows begin from a whorl (posterior suture) on left body side about at level of proximal end of peristomial funnel, i.e., near location of contractile vacuole ( Figs 4 M–N, arrowheads, 5G–H, asterisks) to radiate over ventral and dorsal sides toward right body margin; some kineties shortened anteriorly or posteriorly. Right suture extends from base of peristomial projection to anterior body end; formed by obliquely abutting ventral and dorsal ciliary rows ( Fig. 4M , arrow). Peristomial projection conspicuous because it occupies on average 38% of body length and measures 23–34 × 9–15 μm after protargol impregnation. Peristomial opening situated on left ventral side of peristomial projection, roughly triangular and relatively large, i.e., about 17% of body length and 11–15 × 9–12 μm in size after protargol impregnation ( Figs 4 A–M, 5A–G). Peristomial funnel approximately 34 μm long in protargol preparations. Adoral zone extends slightly obliquely from distal end of peristomial projection across right side of peristomial funnel to terminate about at level of base of peristomial projection; occupies 36% to 50% of body length; composed of on average 32 membranelles; cilia of distalmost membranelles about 8 μm long in vivo and projecting out of peristomial funnel ( Table 2 ; Figs 4A, L , 5 B–G). Paroral membrane diplostichomonad, i.e., composed of two rows of basal bodies; runs in parallel with adoral zone on opposite side of peristomial funnel; commences about at level of proximal end of peristomial opening and terminates near cytostome at proximal end of peristomial funnel ( Figs 4L , 5E ). Pharyngeal fibres originate from proximal end of adoral zone and paroral membrane, run transversely leftwards forming a conical funnel about 12 μm long in vivo.