Uronema nigricans (Müller, 1786) Florentin, 1901
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publication ID |
https://doi.org/ 10.4467/16890027AP.17.003.6967 |
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DOI |
https://doi.org/10.5281/zenodo.8363771 |
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persistent identifier |
https://treatment.plazi.org/id/4A1B145E-FFC5-FFA8-532D-08D65C21873D |
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treatment provided by |
Felipe |
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scientific name |
Uronema nigricans (Müller, 1786) Florentin, 1901 |
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Uronema nigricans (Müller, 1786) Florentin, 1901 View in CoL View at ENA
( Figs 2A, C, F View Fig , 3A–M View Fig , Table 1 View Table 1 )
Uronema nigricans has been redescribed several times since its first recording. However, high-quality photomicrographs of protargol-stained individuals and SSU rDNA sequencing were not available previously. In this study, we determined an improved diagnosis and a detailed redescription based on previous and present data.
Improved diagnosis: Cell size ca. 20–50 μm × 10–25 μm in vivo with a truncated apical plate; pellicle thin and inconspicuously notched, with ridges located longitudinally along ciliary rows; 10–15 somatic kineties, somatic kinety 1 usually shortened, posterior end extending at about three fourths to four fifths of cell; oral apparatus typical of the genus, membranelle 1 clearly separated from other membranelles; freshwater and brackish water habitat.
Deposition of voucher slides: Two voucher slides (registration nos. LMJ2015120701-1 and LMJ2015120701-2) have been deposited in Laboratory of Protozoology, Ocean University of China, Qingdao, China.
Morphological description of Shenzhen population: Cell size in vivo about 30–40 μm × 12–20 μm. Cell shape elongate-elliptical in outline. Anterior end flat, with a prominent apical plate. Posterior part broadly rounded ( Figs 2A View Fig , 3A–C, E View Fig ). Buccal field about half body length and slightly concave. Pellicle thin and inconspicuously notched with ridges located longitudinally along ciliary rows ( Figs 2A View Fig , 3A, E View Fig ). No extrusomes detected in vivo. Cytoplasm colorless to slightly grayish, containing several bar-like crystals distributed in anterior and posterior portions. Well-fed individuals containing several to many grayish-green food vacuoles, leading to a dark gray body color at low magnifications ( Figs 3A–E View Fig ). Single contractile vacuole subcaudally positioned, about 3–4 μm in diameter when fully expanded, pulsating at intervals of 6–8 s ( Figs 2A View Fig , 3A View Fig ). Somatic cilia about 5–7 μm long in vivo, densely arranged ( Figs 2A View Fig , 3A–E View Fig ); single caudal cilium approximately 15–20 μm long ( Figs 2A View Fig , 3A, C, D View Fig ). Single spherical to oval macronucleus located centrally or slightly ahead of mid-body, about 10 μm in diameter in protargol preparations ( Figs 2F View Fig , 3J–M View Fig ). Locomotion by swimming moderately fast, but cells observed mostly crawling on substrates or resting on the bottom of petri dish when not disturbed.
Somatic ciliature as shown in Figs 2C, F View Fig , 3F–M View Fig . Thirteen to fifteen somatic kineties (SKs) arranged longitudinally, forming a small glabrous area at anterior end ( Figs 2C, F View Fig , 3J–M View Fig ). Somatic kinety 1 (SK1, kinety on right of buccal field) usually shorter than other SKs, with posterior end terminating at about three fourths to four fifths of cell ( Figs 2C View Fig , 3J, L View Fig ). Somatic kinety n (SKn, kinety on left of buccal field) located slightly posteriorly with anterior end commencing at front part of membranelle 1 (M1) ( Figs 2C View Fig , 3J, L View Fig ). In general, each kinety composed of closely arranged dikinetids in anterior part and loosely arranged monokinetids posteriorly ( Figs 2C, F View Fig , 3J–M View Fig ). Dikinetids of some individuals extending to the posterior end, almost occupying four-fifths of SK. Somatic kinety 1 composed of 15–19 kinetids, including four to 14 dikinetids, while SKn composed of 15–20 kinetids, with three to 10 dikinetids ( Figs 2C View Fig , 3J, L View Fig ). The middle SK on the dorsal side comprising 12–15 kinetids ( Figs 2F View Fig , 3K, M View Fig ).
Buccal apparatus similar to its congeners ( Figs 2C View Fig , 3I, L View Fig ). Membranelle 1 (M1) single-rowed and positioned near apical plate, clearly separated from other membranelles. It consisted of 5 or 6 basal bodies arranged in one row and a central basal body slightly deviated to the left (towards SKn) ( Figs 2C View Fig , 3I, J, L View Fig ). Membranelle 2 (M2) almost equal to M 1 in length and composed of two or three longitudinal rows of basal bodies ( Figs 2C View Fig , 3H, I, L View Fig ). Membranelle 3 (M3) composed of about seven to nine basal bodies, forming a small patch ( Figs 2C View Fig , 3I, L View Fig ). Paroral membrane (PM) on right of shallow buccal cavity, composed of two rows of basal bodies in a zigzag pattern, and extending anteriorly to about middle portion of M2 ( Figs 2C View Fig , 3H–J, L View Fig ). Scutica observed usually consisting of two or three pairs of basal bodies with one or two basal bodies positioned posteriorly ( Figs 2C View Fig , 3F, G, L View Fig ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.