Uronychia xinjiangensis, Shi & Liu & Wang & Hu, 2017

Shi, Xinlu, Liu, Guijie, Wang, Chundi & Hu, Xiaozhong, 2017, Description of a New Brackish Water Ciliate, Uronychia xinjiangensis n. sp. (Ciliophora, Euplotida) Based on Morphology, Morphogenesis and Molecular Phylogeny, Acta Protozoologica 56 (4), pp. 303-315 : 304-305

Uronychia xinjiangensis n. sp. ( Figs 1–7 , Tables 1 and 2)

Diagnosis

Body oval-shaped, size about 60–90 × 40–68 µm in vivo. Two macronuclear nodules; the posterior part of adoral zone composted of three membranelles; always two fine ventral cirri and one small buccal cirrus; the dorsal kinety 1 consisting of about 36 basal body pairs. Brackish water habitat.

Figures

Fig. 1. Uronychia xinjiangensis n. sp. in vivo (A) and after protargol staining (B–F). (A) Ventral view of a representative individual. (B, C) Ventral and dorsal view of the holotype specimen, showing the ciliature and nuclear apparatus. Frontal-midventral-transverse cirri which originate from the same anlage are connected by a broken line. (D) Ventral view of an early divider, showing the formation of cirral anlagen and OP. (E, F) Ventral and dorsal view of the same early divider, showing the development of cirral anlagen and OP as well the formation of proter’s oral primodirum, left marginal anlagen (arrows in E) and replication bands (arrow in F) and dorsal kinety anlagen in the two rightmost old structures; arrowhead indicates short cirral anlage.AZM1,2, anterior and proximal part of adoral zone of membranelles; BC, buccal cirrus; CA, cirral anlagen; CC, caudal cirri; DK1-3, dorsal kineties 1–3; FC, frontal cirri; LMC, left marginal cirri; Ma, macronuclear nodule; OP, opisther’s oral primodium; PM, paroral membrane; POP, proter’s oral primordium; TC, transverse cirri; VC, ventral cirri. Scale bars: 20 μm.

Fig. 2. Morphogenesis of Uronychia xinjiangensis n. sp. after protargol staining (A–F). (A, B) Ventral and dorsal view of the same specimen, arrows in A and B show cirral anlagen and two caudal cirri in the rightmost dorsal kinety anlagen of both proter and opisthe, respectively, arrowheads in A and B mark left marginal anlagen and replication bands, respectively. (C) Ventral view of a middle divider, arrowheads mark the development of left marginal anlagen. (D) Ventral view of a middle divider, showing the formation of paroral membrane anlagen and the segmentation of cirral anlagen (arrows), dedifferentiation of the old paroral membrane. (E, F) Ventral and dorsal view of the same late divider, showing the formation of new membranelles and cirri and other dorsal kineties anlagen, arrows show de novo formation of a frontal cirrus beside new paroral membrane OP, opisthe’s oral primordium; PMA, paroral membrane anlage; POP, proter’s oral primordium.Scale bars: 20 μm.

Fig. 3. Morphogenesis of Uronychia xinjiangensis n. sp. after protargol staining (A–F). (A, B) Ventral and dorsal view of the same late divider, showing migration of new structures and the formation of spherical fused macronucleus. (C, D) Ventral and dorsal view of the same late divider, five new membranelles combine with six retained membranelles to form anterior part of adoral zone of membranelles in the proter, the macronucleus dividing once. (E, F) Ventral and dorsal view of the same daughter cell just after fusion, showing infraciliature and nuclear apparatus. Scale bars: 20 μm.

Fig. 4. Microphotographs of Uronychia xinjiangensis n. sp. from life (A–L). (A, C, D) Ventral views of different cells, showing variation of body shape, arrow shows cilia in AZM1. (B) Dorsal view showing inclusions, a small spur-like protrusion (arrow in B), and anterior membranelles (arrow in D). (E) Partially lateral view. (F) Anterior portion showing spur-like bulge (arrow) at anterior margin of body and AZM1. (G) Ventral view of posterior part showing AZM2, and small left marginal cirrus (arrow). (H) Ventral view of anterior part, showing frontal cirri. (I) Ventral view of posterior part, showing the fine rightmost transverse cirrus (arrow) and left marginal cirri. (J) Ventral view, showing two fine ventral cirri (arrows). (K) Depicting dorsal bristles. (L) Dorsal view, to show caudal cirri located at concave area and dorsal grooves (arrows). AZM1,2, anterior and proximal part of adoral zone of membranelles; CC, caudal cirri; FC, frontal cirri; LMC, left marginal cirri; TC, transverse cirri. Scale bars: 20 μm.

Fig. 5. Photomicrographs of Uronychia xinjiangensis n. sp. after protargol staining (A–I). (A–C, I) Ventral and dorsal views of specimens at interphase, showing ciliature and macronuclear nodules, arrow showing the small left marginal cirrus. (D, E) Anterior view, to showAZM1 and frontal cirri. (F) Arrows show two fine ventral cirri. (G, H) Depicting AZM2 and left marginal cirri. AZM1,2, anterior and proximal part of adoral zone of membranelles; CC, caudal cirri; DK3, dorsal kinety 3; FC, frontal cirri; LMC, left marginal cirri; Ma, macronuclear nodule; PM, paroral membrane; TC, transverse cirri. Scale bars: 20 μm.

Fig. 6. Photomicrographs of Uronychia xinjiangensis n. sp. after protargol staining (A–I). (A–C) Opisthe’s oral primordium at early dividers. (D) Proter’s oral primordium. (E, F) Fontal-ventral-transverse cirral anlagen of early dividers. (G) A later divider showing the completion of development of oral primordium and cirral anlagen, arrows and arrow show newly formed ventral and frontal cirri respectively in the opisthe. (H, I) The same late divider showing the posterior part of adoral zone of membranelles (arrowheads) and the longest dorsal kinety 3 (arrows). AZM1, the anterior part of adoral zone of membranelles; CA, cirral anlagen; CC, caudal cirri; LMC, left marginal cirri; OP, opisthe’s oral primordium; POP, proter’s oral primordium; TC, transverse cirri. Scale bars: 20 μm.

Fig. 7. Phylogenetic tree inferred by ML and BI of SSU rRNA gene sequences. Numbers near branches denote ML bootstraps value/BI posterior probability value. ‘*’ indicates topology that differ between ML and BI phylogenies. All branches are drawn to scale. The scale bar corresponds to 5 substitutions per 100 nucleotide positions. GenBank accession numbers are given for each species. Classification is mainly according to Lynn (2008).