Deviata Eigner, 1995

Song, Wenya, Dong, Jingyi, Lu, Xiaoteng, Al-Farraj, Saleh A., Song, Weibo, Hines, Hunter N. & Luo, Xiaotian, 2023, Morphological, ontogenetic, and molecular investigations of freshwater hypotrich ciliates from China revealed a new genus Heterodeviata gen. nov. (Protista: Ciliophora), and a novel limnetic population of Deviata multilineae, Zoological Journal of the Linnean Society 199 (1), pp. 263-279 : 269-271

Deviata Eigner, 1995

Deviata multilineae Zhang et al., 2022 ( Fig.7A–N ) Deposition of voucher specimens: Three voucher slides (No. SWY2020051501/1–3) with protargol-stained specimens were deposited in the Laboratory of Protozoology, Ocean University of China, ºingdao, China.

Cell size 150–175 × 40–60 μm (160 × 50 μm on average) in vivo (N = 6), with ratio of length to width in vivo ranging from 2.8 to 3.9; about 165 × 83 μm (140–185 × 55–116 μm), length:width ratio about 2.0:1 (1.6–2.9:1) asser protargol impregnation. Cell flexible but not contractile, outline elongate elliptical, usually with anterior part wider than the posterior one ( Fig. 7A–D, F–H ). Algae in food vacuole rendered cell yellow/ greenish at low magnification ( Fig. 7A, F–H ). Cytoplasm colourless, with numerous colourless globules (0.75–1.5 μm) and many transparent colourless inclusions (2–11 μm), most being spherical and located in the middle of the cell ( Fig. 7E, I ). Cortical granules absent. Four macronuclear nodules, ellipsoidal-shaped, 15–18 × 13–16 μm in vivo, usually two micronuclei, each one usually located between a pair of macronuclear nodules ( Fig. 7I, K, N ). Contractile vacuole about 15 μm when full, located at the equatorial level, near less cell margin ( Fig. 7A, B–D, H ). Collecting canals absent. Locomotion by slowly floating in water, sometimes crawling around the substratum. No cell division, cysts, or conjugation were observed.

The adoral zone of membranelles occupies 28% of cell length in protargol preparations, composed of 23–35 membranelles ( Table 1). Paroral and endoral consisted of single-rowed dikinetids, nearly parallel to each other in most cells (intersected in two out of 15 cells examined), with the former shorter than the laưer ( Fig. 7J, M ). The cytopharyngeal fibres extend posteriorly from the cytostome ( Fig. 7J ). Length of cirri in vivo about 11–13 μm. Three frontal cirri, usually one buccal cirrus located right to the anterior end of the paroral and anterior of the endoral (two buccal cirri observed in three out of 20 cells), three to seven parabuccal cirri behind the right frontal cirrus ( Fig. 7J, M, N ). Three frontoventral cirral rows, frontoventral cirral row 1 (FVR1) commences at right of right frontal cirrus and terminates at posterior 15% of cell length. In six out of 15 cells, FVR1 consisting of two parts: the anterior part terminates behind the proximal end of AZM, the posterior part commences at the right of several last cirri of anterior part ( Fig. 7J, N ). Another two frontoventral cirral rows terminate at the rear end of the cell ( Fig. 7J, N ). Eight to eleven less marginal rows, most of them located on the dorsal side; two or three right marginal rows, most of them distributed on the ventral side ( Fig. 7J, K, L, N ).

Three long dorsal kineties (DK), dorsal bristles inconspicuous in vivo. DK1 with 9–17 dikinetids, DK2 with 17–27 dikinetids, DK3 with 11–17 dikinetids. Caudal cirri absent ( Fig. 7K ).

18S rRNA gene sequence and phylogenetic analyses ( Figs 8 , 9 )

The two new 18S rRNA gene sequences obtained in this study were deposited in GenBank. Their lengths, GC-content, and accession numbers are as follows: Heterodeviata sinica 1571 bp, 45.59%, OP537913; Deviata multilineae 1630 bp, 45.77%, OP537914.

Phylogenetic trees based on 18S rRNA gene sequence data using BIandMLanalysesaremostlycongruent, therefore,onlytheMLtree isshownwithsupportsfrombothalgorithms ( Fig.2A ). Accordingto the 18S rRNA gene tree, all deviatids group together in a large clade with high to full support (97%ML/1.00 BI), in which Heterodeviata sinica is placed in a subclade including D. parabacilliformis , D. rositae , and Pseudosincirra longicirrata with low support (69%ML/0.54BI). However, the position of H. sinica is not robust due to the low support for the cluster of H. sinica , D. parabacilliformis , and D. rositae in the ML tree (50%) and the incongruent topology in the BI tree ( Fig. 2C ). Furthermore, the systematic relationship of Heterodeviata with related genera is shown in Figure 2B .

Comparing the two new 18S rRNA sequences with seven available deviatid sequences ( Fig. 8 ), Heterodeviata sinica differs from the other deviatid sequences by 31–38 nucleotide positions (corresponding to 97.5–97.9% similarity). It is noteworthy that for the sequence of Perisincirra sp. (KY855575, submiưed by Nitla from Pisa University), the morphological characterization was unavailable, but there were no nucleotides differences from Deviata brasiliensis , which suggests that Perisincirra sp. (KY855575) was misidentified, and probably is conspecific with Deviata brasiliensis . More detailed information about the nine deviatid sequences are presented within Figure 8 .

Figures

Figure 2. A, maximum likelihood tree inferred from 18S rRNA gene sequences, showing the phylogenetic positions of the two newly sequenced species. Numbers near the nodes represent the ML bootstrap support and BI posterior probability values. Fully supported (100%/1.00) branches are marked with solid circles. ‘Asterisks’ indicate disagreement between the ML and BI trees.Sequences newly obtained are in pink. The scale bar corresponds to one substitution per 100 nucleotide positions. B, the tree is made referring to the ML tree in a radiation view, showing the likely systematic relationship of Heterodeviata with related genera. C, topology of species within Deviatidae in Bayesian inference (BI) tree.‘**’ indicates the sequence Perisincirra sp. (KY855575) is probably misidentified, which should be conspecific with Deviata brasiliensis.

Figure 7. Deviata multilineae from life (A–I) and asser protargol impregnation (J–N). A, F, ventral view of a representative individual, arrowhead in (F) marks the algae in the cell. B–D, G, H, ventral views of different cells, arrowheads indicate contractile vacuole.E, ventral view, showing the detail of cirri and their surrounded globules.I, denoting the macronuclear nodules and the cytoplasm.J, K, N, ventral (J, N) and dorsal (K) view of the same representative cell, showing infraciliature and nuclear apparatus, arrowhead in (J) marks the buccal cirrus, arrows and arrowheads in (K, N) indicate macronuclear nodules and micronuclei, respectively.L, dorsal view to show the less marginal rows on dorsal side. M, ventral view, arrowhead indicates buccal cirrus. 1–3, dorsal kineties 1–3; E, endoral; FC, frontal cirri; FVR1–3, frontoventral cirral rows 1–3; LMR, less marginal row; Ma, macronuclear nodules; P, paroral; PBC, parabuccal cirri; RMR, right marginal row. Scale bars: 50 μm.

Figure 8. Nucleotide differences between deviatids based on 18S rRNA gene sequences.In (A), the lower less values of the table indicate the sequence similarity, the upper right numbers are numbers of nucleotide differences.The numbers in the header (B) indicate the unmatched site positions. In A, B, the newly obtained sequences are in red.‘**’ indicates the sequence Perisincirra sp. (KY855575) which was likely misidentified and can be considered conspecific with Deviata brasiliensis. ‘H’,Heterodeviata.

Figure 9. Comparison of Heterodeviata with related genera within Deviatidae and Kahllidae that possess three frontal cirri, at least one short or long frontal ventral cirral row right of the cell midline, at least one less marginal row, and one dorsomarginal kinety.Figures in the upper and lower row show the dorsal kinety paưern and cirral paưern of corresponding genera, respectively. Old (parental) structures (marginal cirri or dorsal kineties) are depicted by contour.Abbreviations:BC, buccal cirri; CC, caudal cirri; DK, dorsal kinety; FC, frontal cirri; FVR, frontoventral cirral row; LMR, less marginal row; PBC, parabuccal cirri; RMR, right marginal row; TC, transverse cirri.