Acanthocystis turfacea Carter, 1863
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publication ID |
https://doi.org/ 10.4467/16890027AP.18.018.10094 |
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persistent identifier |
https://treatment.plazi.org/id/32645169-EC14-FF86-FF51-FA47F360FB77 |
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treatment provided by |
Felipe |
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scientific name |
Acanthocystis turfacea Carter, 1863 |
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Acanthocystis turfacea Carter, 1863 ( Figs 1C View Fig , 4E–G)
Description: Diameter of protoplast of living cell is 29 µm. Two types of spine scales, both consist of a hollow cylindrical shaft and circular base, distal part of shaft divided into 2 furcae, without membrane between tips of furcae. Long spine scales: shaft is 13.06–16.50
µm in length, 0.35–0.44 µm in diameter, base is 2.06– 2.43 µm in diameter; furcae pointed, 0.53–0.89 µm in length, distance between tips of furcae – 0.59–0.82 µm. Short spine scales: shaft is 6.21–8.85 µm in length, 0.35–0.40 µm in diameter, base is 1.74–2.09 µm in diameter; long furcae (2.71–3.69 µm) slightly tapers to round tips, distance between tips of furcae 3.22–5.27 µm. Oval plate scales are 3.74–4.50×1.98–2.54 µm, with large rare granules, medial thickening (1.46– 2.33×0.22–0.23 µm) and dense margins.
Remarks: Morphology of observed scales corresponds to previous descriptions. Some authors noted smaller spine scales of both type: length of shaft – 1.8– 11.5 µm, diameter of base – 0.37–1.6 µm ( Dürrschmidt 1985, Croome et al. 1987, Leonov and Plotnikov 2009, Plotnikov and Ermolenko 2015, Plotnikov and Gerasimova 2017), as well as larger length of shaft – up to 65 µm, diameter of shaft – up to 0.7 µm ( Nicholls 1983, Croome 1986, Prokina et al. 2017c).
Distribution: Freshwaters of Asia ( Biyu 2000, Charubhun and Charubhun 2000, Takamura et al. 2000), N. America ( Nicholls 1983), S. America ( Dürrschmidt 1985), Australia ( Croome 1986); marine waters of Europe ( Vørs 1992, Mikrjukov 1999, Leonov 2010a), Antarctica ( Croome et al. 1987) . It was found in Russia in freshwaters of European part ( Mikrjukov 1993a, Leonov and Plotnikov 2009, Leonov 2010 a, Plotnikov and Ermolenko 2015, Prokina et al. 2017c), in saline inland waters of Orenburg and Volgograd Regions ( Gerasimova and Plotnikov 2015, Plotnikov and Gerasimova 2017).
****Raphidocystidae Zlatogursky in Zlatogursky et al., 2018
Raphidocystis symmetrica (Penard, 1904) Zlatogursky in Zlatogursky et al., 2018 [bas.: Raphidiophrys symmetrica Penard, 1904 ; syn.: Polyplacocystis symmetrica (Penard, 1904) Mikrjukov, 1996 ] ( Figs 1D View Fig , 4H–K)
Description: Oval plate scales are 6.02–8.68×2.06– 3.09 µm. Length to width ratio is 1.85–3.41. Dense marginal rim is 0.21–0.34 µm in diameter. Inner space of scale with reticular texture ( Fig. 4K). Longitudinal rib (0.08–0.14 µm in length) divided scale into two halves.
Remarks: Scales of this species are similar to plate scales of R. ambigua and R. tubifera . R. ambigua differs by the presence of narrowed elongate types of plate scales; R. tubifera differs by the presence of funnel-shaped spine scales.
Distribution: Freshwaters of Europe ( Siemensma and Roijackers 1988b), N. America ( Nicholls and Dürrschmidt 1985), Greenland ( Ikävalko et al. 1996). It was found in Russia in freshwaters of Voronezh Region (Leonov and 2010a).
***Pterocystida Cavalier-Smith et von der Heyden, 2007 emend. Shishkin et Zlatogursky, 2018
****Raphidista Shishkin et Zlatogursky, 2018
***** Choanocystidae Cavalier-Smith et von der Heyden, 2007
Choanocystis aculeata (Hertwig et Lesser, 1874) Siemensma et Roijackers, 1988 [bas.: Acanthocystis aculeata Hertwig et Lesser, 1874 ; syn.: A. serrata Nicholls, 1983 ] ( Figs 1E View Fig , 4L–O)
Description: Diameter of protoplast of living cells is 38–40 µm. Spine scales consist of a hollow cylindrical shaft, which asymmetrically sitting on circular flattened base. Shaft is 4.92–13.72 µm in length, diameter of proximal part is 0.47–0.63 µm, diameter of distal part is 0.25–0.29 µm. Proximal part (1/3 of the entire length) with round finger-like outgrowths (0.11–0.45 µm in length, 0.05–0.39 µm in diameter). Tip divided on 4–7 teeth. Base is 1.69–2.47 µm in diameter, with a small excavation. Dumbbell-shaped plate scales are 4.36–5.47 µm in length, width of expanded part is 2.57–3.05 µm, width of narrowed central part is 0.88– 1.73 µm.
Remarks: Observations of the scales are in the agreement with previous descriptions. Some authors observed additionally very long plate scales (up to 12.9 µm) ( Dürrschmidt 1985, Siemensma and Roijackers 1988a). Nicholls (1983) described longer outgrowths (up to 0.7 µm); Croome (1986) observed the absence of outgrowths on spine scales of some cells.
Distribution: Freshwaters of Europe ( Siemensma and Roijackers 1988 a, Mikrjukov 1993b), Asia ( Wujek and Saha 2006), N. America ([as A. serrata ] Nicholls 1983, Wujek 2003), S. America ( Dürrschmidt 1985), Australia ( Croome 1986), fresh and marine waters of Crimea ( Mikrjukov 1999). It was found in Russia in freshwaters of European part ( Mikrjukov 1993a).
***** Raphidiophryidae Febvre-Chevalier et Febvre, 1984 emend. Shishkin et Zlatogursky, 2018
Raphidiophrys capitata Siemensma et Roijackers, 1988 [syn.: Raphidiophrys elegans sensu Nicholls et Dürrschmidt, 1985 ] ( Figs 1F View Fig , 5A–B)
Description: Diameter of protoplast of living cells is 48–54 µm. Elongate oval plate scales are 8.36– 12.24×3.38–4.32 µm, with narrowing elongated ends. Length to width ratio is 2.05–4.02. Edges of scales are bent inside and form marginal rim 0.25–0.37 µm in diameter. Radial ribs with variable length extend from edges to the center. Distances between ribs on marginal rim are 0.16–0.30 µm.
Remarks: Morphology of observed scales corresponds to previous descriptions, except larger length to width ratio (3.0–5.4) in the original description ( Siemensma and Roijackers 1988b).
Distribution: Freshwaters of Europe ( Siemensma and Roijackers 1988b), N. and S. America ([as R. elegans ] Nicholls and Dürrschmidt 1985, Wujek 2003). These are the first observations in Russia.
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