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Morphology of two new marine peritrich ciliates from Yellow Sea, Pseudovorticella dingi nov. spec. and P. wangi nov. spec., with supplementary descriptions of P. plicata, P. banatica and P. anomala (Ciliophora, Peritrichia)
Available online at www.sciencedirect.com
European Journal of Protistology 49 (2013) 467–476
Morphology of two new marine peritrich ciliates from Yellow Sea, Pseudovorticella dingi nov. spec. and P. wangi nov. spec., with supplementary descriptions of P. plicata, P. banatica and P. anomala (Ciliophora, Peritrichia) Ping Suna,b , Honggang Maa,∗ , Mann Kyoon Shinc , Khaled A.S. Al-Rasheidd a
Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361005, China c Department of Biological Science, University of Ulsan, Ulsan 680-749, Republic of Korea d Zoology Department, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia b
Received 23 May 2012; received in revised form 4 October 2012; accepted 25 October 2012 Available online 3 January 2013
Abstract Two new marine peritrich ciliates, Pseudovorticella dingi nov. spec. and Pseudovorticella wangi nov. spec. were collected from coastal waters of Qingdao, China. Their living morphology, infraciliature and silverline system were studied using light microscopy and silver staining methods. Pseudovorticella dingi is characterized mainly by the apically located contractile vacuole and the presence of pellicular granules. There are 28–36 and 13–18 transverse silverlines above and below the trochal band, respectively. Infundibular polykinety 3 is composed of three rows, with row 1 conspicuously shorter than the other two. P. wangi is distinguished mainly by having two ventrally located contractile vacuoles. There are 17–20 and 9–11 transverse silverlines above and below the trochal band, respectively. Abstomal end of row 1 of infundibular polykinety 3 diverges from the other two and ends alongside row 3 of infundibular polykinety 2. Pseudovorticella plicata, P. banatica, and P. anomala have been described in Sun et al. (2009); we supplement morphometric data and photographs from life and after silver staining of these three species in the present study. © 2012 Elsevier GmbH. All rights reserved. Keywords: Infraciliature; New taxa; Peritrichs; Pseudovorticella; Silverline system; Taxonomy
Introduction The genus Pseudovorticella was established by Foissner and Schiffmann (1974) to accommodate solitary vorticellids that were similar to Vorticella species but had a reticulate pattern of silverline system as opposed to the transverse pattern of the genus Vorticella. Later, description of the genus was emended by Leitner and Foissner (1997) to
∗ Corresponding
author. E-mail address: [email protected] (H. Ma).
0932-4739/$ – see front matter © 2012 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.ejop.2012.10.001
include features of the oral infraciliature (e.g. the detailed arrangement of the three infundibular polykineties depicted in Figs 1I, 2H, 4F, S, 5G–I) as an essential diagnostic character. Since the establishment of the genus, and especially in recent years, only few members of the genus have been investigated in detail mostly because of the following reasons (Foissner et al. 1992; Ji et al. 2003, 2004; Song 1997; Song and Warren 2000; Sun et al. 2006, 2007): (1) Pseudovorticella has a relatively small number of species compared with Vorticella species and receives little attention in taxonomy despite its wide distribution; (2) Pseudovorticella species
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are very similar in vivo and the known species are insufficiently described; (3) Pseudovorticella species are quite similar to Vorticella species in living morphology, however, the taxonomic status of many Vorticella species themselves is highly doubtful because of a lack of silver staining data, which makes Pseudovorticella become one of the most difficult taxonomic challenges among peritrich ciliates (Clamp 2005, 2006; Foissner 1979; Foissner et al. 1992; Kahl 1933, 1935; Kent 1880–1882; Noland and Finley 1931; Stiller 1971; Wang et al. 2012; Warren 1986, 1987). During a survey of the ciliate diversity in coastal waters of northern China, five members of the genus were discovered. Investigation of the morphology of living cells, and examination of their infraciliature and silverline system after silver staining revealed that two of them represent undescribed species of Pseudovorticella while the other three were the known species, Pseudovorticella plicata, P. banatica and P. anomala. We describe the two new species, Pseudovorticella dingi and P. wangi, as well as offering the morphometric data, photos from both in vivo and after silver staining and supplementary descriptions of P. plicata, P. banatica and P. anomala to expand on those that were either not included or insufficient in Sun et al. (2009).
Materials and Methods All species were collected from coastal area of the Yellow Sea, Shandong, China, using artificial substrates. Slides were fixed to a frame at the sampling sites and immersed to a depth of 1 m for about 10 d to allow colonization (Gong et al., 2005). P. dingi was collected in June, 2004, from a scallopfarming area near Taiping Bay, Qingdao (water temperature 21 ◦ C, salinity ca. 31‰). Pseudovorticella wangi was isolated in April, 2005, from the sandy littoral of a beach near Haibo Bridge, Qingdao (water temperature 14 ◦ C, salinity ca. 30‰). Pseudovorticella anomala and P. plicata were sampled in May and June, 2005, from shrimp-farming ponds near Weihai and Yantai, respectively (water temperature 21 ◦ C, salinity ca. 30‰). Pseudovorticella banatica was collected in October, 2005, from a pond connected with coastal water just behind No. 2 Middle School of Qingdao (temperature 20 ◦ C, salinity ca. 17‰). After collecting the slides, ciliates were isolated by glass micropipettes. Wet mounts of the isolated cells were made, observed under compound microscopes (Olympus, Nikon), and photographed with a digital camera (Pixra, Olympus). The infraciliature was revealed by impregnation with protargol according to the method of Wilbert (1975). The silver nitrate method (Song and Wilbert 1995) was used to demonstrate the silverline system. Counts and measurements of stained specimens were made under 100–1250× magnification. The silver nitrate method was used to demonstrate the silverline system (Song and Wilbert 1995). Drawings of stained specimens were performed at 1000× with the aid of a camera lucida. Terminology mainly follows Lynn (2008).
Results and Discussion Genus Pseudovorticella Foissner and Schiffmann, 1974 Pseudovorticella dingi nov. spec. (Fig. 1A–K; Table 1) Diagnosis: Marine Pseudovorticella. Cell inverted bellshaped, measuring about 40 m × 40 m in vivo. One apically located contractile vacuole. Macronucleus J-shaped. Pellicle with granules. Transverse silverlines numbering 28–36 from peristome to trochal band, 13–18 from trochal band to scopula. Infundibular polykinety 3 consisting of three rows, with row 1 conspicuously shorter than the other two. Type locality: Taiping Bay, Qingdao, China (36◦ 05 01 N; 120◦ 35 29 E). Dedication: The species is named in honor of eminent biologist, Prof. Mingxiao Ding, Peking University, China, in recognition of his significant contributions to the field of cell biology and protozoology. Deposition of slides: The protargol slide (registration number SP–2004–0624–01) containing the holotype speciemen (Fig. 1I; Table 1) and several paratype specimens stained with protargol and silver nitrate (registration number SP–2004–0624–02), respectively, have been deposited in the Laboratory of Protozoology, Ocean University of China, China. Description: Cell inverted bell-shaped, measuring 35–40 m × 35–45 m in vivo, ratio of length to width ca. 1:1, maximum width at peristomial lip (Fig. 1A and H; Table 1). Peristomial lip relatively thin, well extended and body not constricted beneath it. Peristomial disk flat and moderately elevated when cell fully extended. Pellicle smooth at low magnification, while pellicular protuberances clearly visible above 1000× magnification (Fig. 1G, H and K). Cytoplasm colorless or slightly grayish, and some well fed cells packed with many grayish food granules or vacuoles (Fig. 1A and H). Single large contractile vacuole apically located (Fig. 1A). Macronucleus long, J-shaped, with its semicircular oral arm orienting transversely to long axis and locating immediately below the peristome (Fig. 1A). Macronucleus extended aborally from oral end and recurved, forming bottom of “J”. Micronucleus not observed. Stalk approximately 140–180 m long, 4 m in diameter and surface of stalk usually smooth (Fig. 1C–E). Spasmoneme approximately 2 m in diameter, with 0.4 m, grayish thecoplasmic granules sparsely distributed on it (Fig. 1F; Table 1). Oral infraciliature as shown in Fig. 1B. Haplokinety and polykinety completing approximately one circuit together around peristome and continuing into infundibulum, where they separated and made another complete circuit on opposite walls of the passageway before ending at or near the cytostome (Fig. 1B). Polykinety 1 accompanied by two additional polykineties in infundibulum. Each of these infundibular polykineties composed of three rows of
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Fig. 1. A–K. Morphology of Pseudovorticella dingi nov. spec. from life (A, C–H, K) and after impregnation with protargol (B, I) and silver nitrate (J). A, H: Typical zooids at high magnification, arrowheads show pellicular granules. B: Oral infraciliature, arrowhead marks the epistomial membrane, arrow with numerals indicates numbering convention for polykineties and rows of kinetosomes within each polykinety. C–E: Individuals at low magnification. F: Detail of stalk, arrows indicate thecoplasmic granules. G, K: Living zooids at high magnification focused to show the pellicular granules (arrowheads). I: Detailed arrangement of infundibular polykineties. J: Zooid at high magnification focused to show partial silverline system, arrowheads and arrows indicate the trochal band and pellicular pores, respectively. G, germinal kinety; H, Haplokinety; P1–3, infundibular polykinety 1–3; Po, polykinety. Scale bars = 25 m.
kinetosomes spreading sufficiently far apart to be distinct. Adstomal ends of rows in polykinety 1 terminating at slightly different levels; rows 2 and 3 slightly longer than row 1 in polykinety 1. Polykinety 2 terminating between and above adstomal ends of polykinety 1 and polykinety 3. Row 1 conspicuously shorter than rows 2 and 3 in polykinety 3 (Fig. 1B and I); Abstomal end of row 1 clearly separated from the other two, whose adstomal end is near the cytostome at a similar level as rows 2 and 3 of polykinety 1 (Fig. 1I). Germinal kinety lying parallel to the haplokinety within upper half of infundibulum (Fig. 1B). Epistomial membrane short and locating near opening of infundibulum (Fig. 1B). Trochal band composed of a zigzag structure of kinetosomes encircling cell near aboral end (Fig. 1J). Silverline system typical of genus, 28–36 transverse silverlines between peristome and trochal band, and 13–18 between trochal band and scopula. Pellicular pores associated with silverlines observed at high magnification (Fig. 1J; Table 1). Remarks and comparison: Vorticella granulata Kahl, 1933 resembles the new species and comparison should
be made between them. The infraciliature and silverline system of V. granulata have not been described yet. However, Pseudovorticella dingi differs from V. granulata by the combination of the following characters: (1) body shape (inverted-bell shaped vs. elongated bell-shaped); (2) body size (35–40 m vs. 50–60 m); (3) position of contractile vacuole (apically located within peristomial disc vs. dorsally located near infundibulum); (4) appearance of peristomial lip (extended vs. narrow); (5) shape of macronucleus (J-shaped vs. C-shaped) (Fig. 3B and D; Table 2; Kahl 1933). Regarding body shape, Pseudovorticella dingi should also be compared with P. sphagni Foissner and Schiffmann, 1974 (Fig. 3C) and P. jaerae (Precht, 1935) Sun et al., 2009 (Fig. 3A). Pseudovorticella sphagni is a freshwater species and has two contractile vacuoles and fewer silverlines, thus, it cannot be confused with P. dingi (Foissner and Schiffmann 1974). Pseudovorticella jaerae is separated from P. dingi by its ventrally located contractile vacuole (vs. apically located) and fewer silverlines (20–26, 8–11 vs. 28–36, 13–18; Table 2; Sun et al., 2009).
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Table 1. Morphometric characterization of Pseudovorticella dingi nov. spec., P. wangi nov. spec., P. plicata, P. banatica, and P. anomala. Charactera
Species
Min
Max
Mean
Body length in vivo
P. dingi P. wangi P. plicata P. banatica P. anomala
35 45 80 70 35
40 60 90 80 40
37.5 53.2 84.0 76.0 38.0
1.6 4.7 3.7 3.3 2.1
20 20 10 9 12
Body width in vivo
P. dingi P. wangi P. plicata P. banatica P. anomala
35 30 40 60 30
45 45 45 70 40
41.5 38.3 41.2 62.2 36.0
2.5 4.6 1.9 3.7 0.8
20 20 10 9 12
Width of peristomial lip
P. dingi P. wangi P. plicata P. banatica P. anomala
54 44 47 64 29
58 47 51 66 31
56.4 45.7 49.6 65.0 30.3
1.3 1.0 1.1 0.8 0.7
20 20 20 20 20
Thickness of peristomial lip
P. dingi P. wangi P. plicata P. banatica P. anomala
4 6 6 5 4
5 7 7 6 5
4.6 6.5 6.4 5.5 4.6
0.5 0.5 0.5 0.5 0.4
20 20 20 20 20
Length of stalk
P. dingi P. wangi P. plicata P. banatica P. anomala
140 150 280 380 50
180 250 360 500 80
163.1 216.7 323.9 422.3 66.0
11.9 30.7 26.8 37.2 8.5
18 16 11 13 11
Width of stalk
P. dingi P. wangi P. plicata P. banatica P. anomala
4 5 5 6 3
4 6 7 8 4
4 5.6 6.2 6.6 3.3
0.0 0.5 0.9 0.6 0.5
18 16 11 13 11
Width of Spasmoneme
P. dingi P. wangi P. plicata P. banatica P. anomala
2 2 2 3 2
2 3 3 4 2
2.0 2.6 2.5 3.0 2.0
0.0 0.5 0.5 0.2 0.0
18 16 11 13 11
Number of silverlines from peristome to trochal band
P. dingi P. wangi P. plicata P. banatica P. anomala
28 17 41 35 34
36 20 46 39 39
31.7 18.4 43.4 37.2 35.8
2.9 1.1 2.0 1.4 1.6
6 7 5 7 7
Number of silverlines from trochal band to scopula
P. dingi P. wangi P. plicata P. banatica P. anomala
13 9 14 12 16
18 11 17 16 19
16.2 10.1 14.8 14.2 17.5
2.1 0.8 1.1 1.3 1.3
5 8 6 6 6
SD
n
a Data based on live observation and silver-impregnated specimens. Measurements in m. Abbreviations: Max, maximum; Mean, arithmetic mean; Min, minimum; n, sample number; SD, standard deviation.
Pseudovorticella wangi nov. spec. (Fig. 2A–J; Table 1) Diagnosis: Marine Pseudovorticella. Cell elongate, trumpet-shaped, measuring 50 m × 40 m in vivo with a relatively broad, flat peristomial lip about 45 m across, below which body slightly constricted. Two small contractile
vacuoles ventrally located. Macronucleus J-shaped. Transverse silverlines numbering 17–20 from peristome to trochal band, 9–11 from trochal band to scopula. Polykinety 3 consisting of three rows, with abstomal end of row 1 of polykinety 3 diverging from the other two and ending alongside row 3
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Table 2. Comparison of Pseudovorticella dingi nov. spec. with morphologically similar species. Character
P. dingi
Vorticella granulata
P. sphagni
P. jaerae
Body size in vivo (m) Body shape Number and position of contractile vacuole Appearance of peristomial lip Macronucleus Number of silverlines above and below trochal band Habitat Data source
35–40 × 35–45 Inverted bell 1, apical Extended J-shaped 28–36; 13–18 Marine Present study
50–60 in length Elongate 1, dorsal Narrow C-shaped –; – Freshwater Kahl (1935)
40–50 in length Inverted bell 2, ventral and dorsal Relatively extended J-shaped 26–27; 8–10 Freshwater Foissner (1979)
40–55 × 25–45 Inverted bell 1, dorsal Relatively extended J-shaped 20–26; 8–11 Marine Sun et al. (2009)
“–”, data is not available.
of polykinety 2. Adstomal end of rows 2 and 3 of polykinety 3 prolonging and converging with row 3 of polykinety 1. Type locality: Haibo Bridge, Qingdao, China (36◦ 08 94 N; 120◦ 37 16 E). Dedication: We name this new species in honor of Prof. Jianguo Wang, Institute of Hydrobiology, China, who has
made great contributions to the field of parasitic protozoology. Deposition of slides: The protargol slide (registration number SP–05–0408–01) containing the holotype specimen (Fig. 2H; Table 1) and several paratype specimens stained with protargol and silver nitrate (registration number
Fig. 2. A–J. Pseudovorticella wangi nov. spec. from life (A, C–F, I, J) and after impregnation with protargol (B, H) and silver nitrate (G). A, D: Typical individuals at low magnification. B: Entire oral infraciliature in dorsal view, arrow with numerals indicates numbering convention for polykineties and rows of kinetosomes within each polykinety, and arrowhead marks epistomial membrane. C, F: Living zooids at high magnification. E: Living zooid at high magnification focused to show the pellicular striations. G: Partial silverline system, arrowheads mark pellicular pores. H: Detailed arrangement of infundibular polykineties. I, J: Zooids at high magnification indicating the two small contractile vacuoles (arrows and arrowheads). G, germinal kinety; H, Haplokinety; P1–3, infundibular polykinety 1–3; Po, polykinety. Scale bars = 30 m.
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Fig. 3. A–H. Living morphology of some species which are similar to the new species described in present study. A: Ventral view of Pseudovorticella jaerae (from Sun et al., 2009). B, D: Ventral view of Vorticella granulata (from Kahl 1935). C: Pseudovorticella sphagni (from Foissner 1979). E: Dorsal view of Pseudovorticella pseudocampanula (from Foissner 1979). F: Ventral view of Pseudovorticella bidulphiae (from Ji et al., 2011). G: Ventral view of Pseudovorticella mutans (from Foissner 1979). H: Pseudovorticella monilata (from Foissner 1979). Scale bars = 40 m.
SP–05–0408–02), respectively, have been deposited in the Laboratory of Protozoology, Ocean University of China, China. Description: Cell 45–60 × 30–45 m, elongated bellshaped (Table 1). Peristomial lip relatively thin, flat and well extended and body slightly constricted beneath it. Peristomial disc flattened and slightly obliquely elevated when cell fully extended (Fig. 2C and F). Pellicle striations could be seen above 400× magnification (Fig. 2E), but surface of cell completely smooth at low magnifications. Oral cilia relatively long and rather stiff (Fig. 2C, D and F).
Cytoplasm grayish and usually containing several yellow greenish food granules 4–12 m in diameter. Two small contractile vacuoles near ventral wall of infundibulum, one located aborally to mid body near middle part of relative short, broad infundibulum, the other located near end of infundibulum at almost same level as anterior one (Fig. 2I and J). In the habitat water in which they were maintained, contractile vacuoles discharging at different rates: the anterior one approximately once a minute, the posterior one approximately once every two minutes. Macronucleus J-shaped with aboral end slightly recurved (Fig. 2C). Micronucleus not observed.
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Stalk measuring approximately 3–5 times the length of cell body and 6 m across (Fig. 2A and D; Table 1). Spasmoneme 2–3 m in diameter with numerous, grayish thecoplasmic granules 0.3–0.5 m in diameter. Oral infraciliature as shown in Fig. 2B and H. Haplokinety and polykinety both making one and one–third turns before entering infundibulum, where they made a further turn. All polykineties consisting of three rows of kinetosomes in lower half of infundibulum. Infundibular polykinety 1 and polykinety 2 longer than polykinety 3. Three rows of polykinety 1 being of almost equal length and terminating at end of infundibulum. Adstomal ends of rows in polykinety 1 terminating at slightly different levels. Adstomal ends of polykinety 2 terminating between polykinety 1 and polykinety 3 and abstomally far to their adstomal ends. Polykinety 1 separated from polykinety 2 by small gap (Fig. 2B and H). Row 1 of polykinety 3 conspicuously shorter than the other two and displaced adstomally for a short distance relative to the other two. Haplokinety passing around infundibulum on wall opposite to polykinety. Germinal kinety lying parallel to upper half of haplokinety (Fig. 2B). Epistomial membrane located near opening of infundibulum as commonly seen in other peritrichs (Fig. 2B). Silverline system reticulate with 17–20 transverse silverlines from peristome to trochal band and 9–11 transverse silverlines between trochal band and scopula. Many pellicular pores sparsely distributed among silverlines (Fig. 2G; Table 1). Remarks and comparison: Pseudovorticella bidulphiae (Stiller, 1939) Ji et al. in Sun et al. (2009) bears a strong resemblance to the new form in terms of body shape, the presence of two contractile vacuoles and its marine habitat. Pseudovorticella bidulphiae, however, has a relatively small size (30–40 vs. 45–60 m), a higher number of silverlines between the peristome and the trochal band (25–31 vs. 17–20) and different structures in polykinety 3 (with only two rows vs. three rows) (Fig. 3F; Table 3; Sun et al., 2009). In regard to its general appearance, the new species should also be compared with three congeners, P. monilata (Tatem, 1870) Foissner and Schiffmann, 1974, P. mutans (Penard, 1922) Foissner, 1979 and P. pseudocampanula Foissner, 1979. Pseudovorticella monilata also has two contractile vacuoles and a J-shaped macronucleus. However, the former is a freshwater species and has a relatively large body size (60–70 vs. 45–60 m) and more silverlines from the trochal band to the scopula (9–18 vs. 9–11) (Fig. 3H; Table 3; Foissner 1979; Foissner et al., 1992). Pseudovorticella mutans (Fig. 3G) and P. pseudocampanula (Fig. 3E) can be distinguished from P. wangi by their habitat (freshwater vs. marine) and the number of contractile vacuoles (1 vs. 2) (Table 3; Foissner 1979).
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Pseudovorticella plicata (Gourret and Roeser, 1886) Sun, Ji, Warren and Song, 2009 (Fig. 4A–J; Table 1) Deposition of slides: One protargol preparation (registration number SP–2005–0618–01) and one silver nitrate preparation (registration number SP–2005–0618–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have already been documented by Sun et al. (2009) (Fig. 4A–E). In this study, we further noted that the cell was not constricted below a relatively broad peristomial lip which had many closely spaced frills that could be observed in vivo under high magnification (Fig. 4I, arrows; Table 1). Telotroch (swarmer) roughly cylindrical, 60 m × 35 m in size (Fig. 4C). Stalk 280–360 m long, relatively thick, 5–7 m wide. Spasmoneme 2–3 m in diameter, with numerous, 0.8–1.2 m, dark gray thecoplasmic granules along its length (Fig. 4J; Table 1). Infraciliature and silverline system as shown in Fig. 4F–H. Trochal band composed of double rows of kinetosomes (Fig. 4B). Silverline system typical of genus, pellicular striae closely spaced, with many pellicular pores sparsely distributed (Fig. 4G and H).
Pseudovorticella banatica (Lepsi, 1947) Sun, Ji, Warren and Song, 2009 (Fig. 4K–T; Table 1) Deposition of slides: One protargol preparation (registration number SP–2005–1016–01) and one silver nitrate preparation (registration number SP–2005–1016–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have already been documented by Sun et al. (2009) (Fig. 4K–N and P–R). In our observations we further noted that the peristomial disc was large and highly elevated above a thin, single layered peristomial lip which was usually the widest part of the cell, measuring about 64–66 m in diameter (Fig. 4Q and R; Table 1). Stalk usually five times length of zooid, but can be up to 500 m long, typically 6–8 m across (Fig. 4K and L). Spasmoneme 3–4 m across, with numerous, conspicuous, dark gray thecoplasmic granules, approximately 0.8 m across (Fig. 4N; Table 1). Infraciliature and silverline system as shown in Fig. 4S and T. Trochal band composed of double rows of kinetosomes encircling cell at approximately one third of body length from
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Fig. 4. A–T. Photomicrographs of Pseudovorticella plicata (A–J) and P. banatica (K–T) from life (A–E, I–R) and after protargol (F, S) and silver nitrate (G, H, T) impregnation. A, B: Zooids at low magnification, arrow indicates trochal band. C: Telotroch. D: Zooid at high magnification to show pellicular striations. E: Zooid at high magnification. F: Detailed arrangement of infundibular polykineties. G, H: Partial silverline system. I: Zooid at high magnification focused to show frills on peristomial lip (arrows). J: Detail of stalk, arrows indicate thecoplasmic granules. K, L, P: Individuals at low magnification. M, Q, R: Zooids at high magnification. N: Detail of stalk, arrows indicate granules. O: Living zooid at high magnification focused to show the pellicular striations. S: Detail of infundibular polykineties. T: Silverline system. P1–3, infundibular polykinety 1–3. Scale bars = 50 m.
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Table 3. Comparison of Pseudovorticella wangi nov. spec. with morphologically similar species. Character
P. wangi
P. bidulphiae
P. monilata
P. mutans
P. pseudocampanula
Body size in vivo (m) Body shape Number and position of contractile vacuole Number of silverlines above and below trochal band Structure of polykinety 3 Habitat Data source
45–60 × 30–45 Elongate 2, ventral
30–40 × 35–40 Elongate 2, ventral
60–70 in length Elongate 1, ventral
65–95 in length Conical 1, ventral
32–50 in length Conical 1, ventral
17–20; 9–11
25–31; 9–13
19–23; 9–18
24–28; 16–19
28–33; 16–18
Three rows Marine Present study
Two rows Marine Sun et al. (2009)
Three rows Freshwater Foissner et al. (1992)
–; – Freshwater Foissner (1979)
–; – Freshwater Foissner (1979)
“–”, data is not available.
scopula. Silverline system typical of genus, and pellicular striae widely spaced with pellicular pores sparsely distributed (Fig. 4O and T). Pseudovorticella anomala (Gourret and Roeser, 1886) Sun, Ji, Warren and Song, 2009 (Fig. 5A–I; Table 1) Deposition of slides: One protargol preparation (registration number SP–2004–0508–01) and one silver nitrate preparation (registration number SP–2004–0508–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have
already been documented by Sun et al. (2009) (Fig. 5A–E). In our study we further observed that the body was constricted deeply beneath a narrow, relatively thick peristomial lip which measured 29–31 m in diameter (Table 1). Peristomial disk extremely flat and slightly elevating above peristomial lip (Fig. 5A–C and E). Telotroch (swarmer) which was also not mentioned in Sun et al. (2009), roughly spherical and about 30 m × 25 m in size (Fig. 5D). Stalk short, approximately 50–80 m long and relatively thin, 3–4 m wide. Spasmoneme 2 m in diameter, with gray thecoplasmic granules 0.3–0.4 m sparsely distributed along its length (Fig. 5A–C; Table 1).
Fig. 5. A–I. Photomicrographs of Pseudovorticella anomala from life (A–E) and after silver nitrate (F) and protargol (G–I) impregnation. A–D: Individuals at low magnification, arrow in (D) shows the forming telotroch. E: A typical zooid at high magnification. F: Partial silverline system, arrowheads indicate trochal band. G–I: General oral infraciliature. Ma, macronucleus; P1–3, infundibular polykinety 1–3. Scale bars = 50 m.
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Infraciliature and silverline system as shown in Fig. 5F–I. Trochal band composed of double rows of kinetosomes encircling cell at approximately one third of body length from scopula (Fig. 5F). Silverline system typical of genus, and pellicular striae closely spaced with pellicular pores sparsely distributed (Fig. 5F).
Acknowledgements This work was supported by the Natural Science Foundation of China (project no. 31272285; 41276139, RCN-BC31111120437), Basic Science Research Program through the NRF funded by the Government of Korea (MEST) (no. 2012R1A1A2005751; M.K. Shin), and King Saud University, Deanship of Scientific Research, Research Group Project (no. RGP-VPP-083; K.A.S. Al-Rasheid). We appreciate the comments of two anonymous reviewers and associate editor, which greatly improved the manuscript.
References Clamp, J.C., 2005. Redescription of Lagenophrys maxillaris (Jankowski, 1993) (Ciliophora Peritrichia, Lagenophryidae), an ectosymbiont of marine amphipods. J. Eukaryot. Microbiol. 52, 38–43. Clamp, J.C., 2006. Redescription of Lagenophrys cochinensis Santhakumari & Gopalan, 1980 (Ciliophora Peritrichia, Lagenophryidae), an ectosymbiont of marine isopods, including new information on morphology, geographic distribution, and intraspecific variation. J. Eukaryot. Microbiol. 53, 58–64. Foissner, W., 1979. Peritriche Ciliaten (Protozoa: Ciliophora) aus alpinen Kleingewässern. Zool. Jb. Syst. 106, 529–558. Foissner, W., Schiffmann, H., 1974. Vergleichende Studien an argyrophilen Strukturen von vierzehn peritrichen Ciliaten. Protistologica 10, 489–508. Foissner, W., Berger, H., Kohmann, F., 1992. Taxonomische und Ökologische Revision der Ciliaten des Saprobiensystems – Band II: Peritrichida, Heterotrichida Odontostomtida. Informationsberichte des Bayer. Landesamtes Wasserwirtsch. 5/92, 1–502. Gong, J., Song, W., Warren, A., 2005. Periphytic ciliate colonization: annual cycle and response to environmental conditions. Aquat. Microb. Ecol. 39, 159–170. Ji, D., Song, W., Al-Rasheid, K.A.S., 2003. Description of a marine peritrichous ciliate, Pseudovorticella sinensis n. sp. (Ciliophora, Peritrichia) from China. J. Eukaryot. Microbiol. 50, 360–365. Ji, D., Song, W., Warren, A., 2004. Pseudovorticella paracratera n. sp., a new marine peritrich ciliate (Ciliophora: Peritrichida) from north China. Hydrobiologia 515, 49–57. Ji, D., Shin, M.K., Choi, J.K., Clamp, J.C., Al-Rasheid, K.A.S., Song, W., 2011. Redescriptions of five species of marine peritrichs, Zoothamnium plumula, Zoothamnium nii, Zoothamnium wangi, Pseudovorticella bidulphiae, and Pseudovorticella marina (Protista, Ciliophora). Zootaxa 2930, 47–59.
Kahl, A., 1933. Ciliata libera et ectocommensalia. In: Grimpe, G., Wagler, E. (Eds.), Die Tierwelt der Nord–und Ostsee, Lief. 23 (Teil II, c3). , pp. 29–146. Kahl, A., 1935. Urtiere oder Protozoa I: Wimpertiere oder Ciliata (Infusoria) 4 Peritricha und Chonotricha. Tierwelt Dtl. 30, 651–886. Kent, W.S., 1880–1882. A Manual of the Infusoria: Including a Description of all Known Flagellate, Ciliate, and Tentaculiferous Protozoa British and Foreign, and an Account of the Organization and Affinities of the Sponges. David Bogue, London. Leitner, A.R., Foissner, W., 1997. Taxonomic characterization of Epicarchesium granulatum (Kellicott 1887) Jankowki, 1985 and Pseudovorticella elongata (Fromentel, 1876) nov. comb., two peritrichs (Protozoa, Ciliophora) from activated sludge. Eur. J. Protistol. 33, 13–29. Lynn, D.H., 2008. The Ciliated Protozoa. Characterization, Classification and Guide to the Literature, 3rd ed. Springer, Dordrecht. Noland, L.E., Finley, H.E., 1931. Studies on the taxonomy of the genus Vorticella. Trans. Am. Microsc. Soc. 50, 81–123. Song, W., 1997. A new genus and two new species of marine peritrichous ciliates (Protozoa, Ciliophora, Peritrichida) from Qingdao, China. Ophelia 47, 203–214. Song, W., Warren, A., 2000. A redescription of Pseudovorticella patellina (O F. Müller, 1776) nov. comb., a peritrichous ciliate (Protozoa: Ciliophora: Peritrichida) isolated from mariculture biotopes in north China. Acta Protozool. 39, 43–50. Song, W., Wilbert, N., 1995. Benthische Ciliaten des Süßwassers. In: Röttger, R. (Ed.), Praktikum der Protozoologie. G. Fischer, New York, pp. 156–168. Stiller, J., 1971. Szájkoszorús Csillósok–Peritricha. Fauna Hung 105, 1–245. Sun, P., Song, W., Warren, A., 2006. Taxonomic characterization of two marine peritrichous ciliates Epicarchesium corlissi n.sp. and Pseudovorticella jiangi n.sp. (Ciliophora: Peritrichia), from northern China. Eur. J. Protistol. 42, 281–289. Sun, P., Song, W., Xu, D., 2007. Two new marine species of Pseudovorticella (Ciliophora Peritrichia) from Qingdao, north China. Acta Protozool. 46, 55–64. Sun, P., Ji, D., Warren, A., Song, W., 2009. Solitary sessilid peritrichs. In: Song, W., Warren, A., Hu, X. (Eds.), Free-living Ciliates in the Bohai and Yellow Seas. Science Press, China, China, pp. 217–256. Wang, H., Clamp, J.C., Shi, X., Laura, U., Liu, G., 2012. Evolution of variations in the common pattern of stomatogenesis in peritrich ciliates: evidence from a comparative study including a new description of stomatogenesis in Pseudepistylis songi Peng et al. J. Eukaryot. Microbiol. 59, 300–324. Warren, A., 1986. A revision of the genus Vorticella (Ciliophora: Peritrichida). Bull. Br. Mus. Nat. Hist. (Zool.) 50, 1–57. Warren, A., 1987. A revision of the genus Pseudovorticella Foissner & Schiffmann, 1974 (Ciliophora: Peritrichida). Bull. Br. Mus. Nat. Hist. (Zool.) 52, 1–12. Wilbert, N., 1975. Eine verbesserte Technik der Protargolimprägnation für Ciliaten. Mikrokosmos 64, 171–179.
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Morphology of two new marine peritrich ciliates from Yellow Sea, Pseudovorticella dingi nov. spec. and P. wangi nov. spec., with supplementary descriptions of P. plicata, P. banatica and P. anomala (Ciliophora, Peritrichia) Ping Suna,b , Honggang Maa,∗ , Mann Kyoon Shinc , Khaled A.S. Al-Rasheidd a
Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361005, China c Department of Biological Science, University of Ulsan, Ulsan 680-749, Republic of Korea d Zoology Department, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia b
Received 23 May 2012; received in revised form 4 October 2012; accepted 25 October 2012 Available online 3 January 2013
Abstract Two new marine peritrich ciliates, Pseudovorticella dingi nov. spec. and Pseudovorticella wangi nov. spec. were collected from coastal waters of Qingdao, China. Their living morphology, infraciliature and silverline system were studied using light microscopy and silver staining methods. Pseudovorticella dingi is characterized mainly by the apically located contractile vacuole and the presence of pellicular granules. There are 28–36 and 13–18 transverse silverlines above and below the trochal band, respectively. Infundibular polykinety 3 is composed of three rows, with row 1 conspicuously shorter than the other two. P. wangi is distinguished mainly by having two ventrally located contractile vacuoles. There are 17–20 and 9–11 transverse silverlines above and below the trochal band, respectively. Abstomal end of row 1 of infundibular polykinety 3 diverges from the other two and ends alongside row 3 of infundibular polykinety 2. Pseudovorticella plicata, P. banatica, and P. anomala have been described in Sun et al. (2009); we supplement morphometric data and photographs from life and after silver staining of these three species in the present study. © 2012 Elsevier GmbH. All rights reserved. Keywords: Infraciliature; New taxa; Peritrichs; Pseudovorticella; Silverline system; Taxonomy
Introduction The genus Pseudovorticella was established by Foissner and Schiffmann (1974) to accommodate solitary vorticellids that were similar to Vorticella species but had a reticulate pattern of silverline system as opposed to the transverse pattern of the genus Vorticella. Later, description of the genus was emended by Leitner and Foissner (1997) to
∗ Corresponding
author. E-mail address: [email protected] (H. Ma).
0932-4739/$ – see front matter © 2012 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.ejop.2012.10.001
include features of the oral infraciliature (e.g. the detailed arrangement of the three infundibular polykineties depicted in Figs 1I, 2H, 4F, S, 5G–I) as an essential diagnostic character. Since the establishment of the genus, and especially in recent years, only few members of the genus have been investigated in detail mostly because of the following reasons (Foissner et al. 1992; Ji et al. 2003, 2004; Song 1997; Song and Warren 2000; Sun et al. 2006, 2007): (1) Pseudovorticella has a relatively small number of species compared with Vorticella species and receives little attention in taxonomy despite its wide distribution; (2) Pseudovorticella species
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are very similar in vivo and the known species are insufficiently described; (3) Pseudovorticella species are quite similar to Vorticella species in living morphology, however, the taxonomic status of many Vorticella species themselves is highly doubtful because of a lack of silver staining data, which makes Pseudovorticella become one of the most difficult taxonomic challenges among peritrich ciliates (Clamp 2005, 2006; Foissner 1979; Foissner et al. 1992; Kahl 1933, 1935; Kent 1880–1882; Noland and Finley 1931; Stiller 1971; Wang et al. 2012; Warren 1986, 1987). During a survey of the ciliate diversity in coastal waters of northern China, five members of the genus were discovered. Investigation of the morphology of living cells, and examination of their infraciliature and silverline system after silver staining revealed that two of them represent undescribed species of Pseudovorticella while the other three were the known species, Pseudovorticella plicata, P. banatica and P. anomala. We describe the two new species, Pseudovorticella dingi and P. wangi, as well as offering the morphometric data, photos from both in vivo and after silver staining and supplementary descriptions of P. plicata, P. banatica and P. anomala to expand on those that were either not included or insufficient in Sun et al. (2009).
Materials and Methods All species were collected from coastal area of the Yellow Sea, Shandong, China, using artificial substrates. Slides were fixed to a frame at the sampling sites and immersed to a depth of 1 m for about 10 d to allow colonization (Gong et al., 2005). P. dingi was collected in June, 2004, from a scallopfarming area near Taiping Bay, Qingdao (water temperature 21 ◦ C, salinity ca. 31‰). Pseudovorticella wangi was isolated in April, 2005, from the sandy littoral of a beach near Haibo Bridge, Qingdao (water temperature 14 ◦ C, salinity ca. 30‰). Pseudovorticella anomala and P. plicata were sampled in May and June, 2005, from shrimp-farming ponds near Weihai and Yantai, respectively (water temperature 21 ◦ C, salinity ca. 30‰). Pseudovorticella banatica was collected in October, 2005, from a pond connected with coastal water just behind No. 2 Middle School of Qingdao (temperature 20 ◦ C, salinity ca. 17‰). After collecting the slides, ciliates were isolated by glass micropipettes. Wet mounts of the isolated cells were made, observed under compound microscopes (Olympus, Nikon), and photographed with a digital camera (Pixra, Olympus). The infraciliature was revealed by impregnation with protargol according to the method of Wilbert (1975). The silver nitrate method (Song and Wilbert 1995) was used to demonstrate the silverline system. Counts and measurements of stained specimens were made under 100–1250× magnification. The silver nitrate method was used to demonstrate the silverline system (Song and Wilbert 1995). Drawings of stained specimens were performed at 1000× with the aid of a camera lucida. Terminology mainly follows Lynn (2008).
Results and Discussion Genus Pseudovorticella Foissner and Schiffmann, 1974 Pseudovorticella dingi nov. spec. (Fig. 1A–K; Table 1) Diagnosis: Marine Pseudovorticella. Cell inverted bellshaped, measuring about 40 m × 40 m in vivo. One apically located contractile vacuole. Macronucleus J-shaped. Pellicle with granules. Transverse silverlines numbering 28–36 from peristome to trochal band, 13–18 from trochal band to scopula. Infundibular polykinety 3 consisting of three rows, with row 1 conspicuously shorter than the other two. Type locality: Taiping Bay, Qingdao, China (36◦ 05 01 N; 120◦ 35 29 E). Dedication: The species is named in honor of eminent biologist, Prof. Mingxiao Ding, Peking University, China, in recognition of his significant contributions to the field of cell biology and protozoology. Deposition of slides: The protargol slide (registration number SP–2004–0624–01) containing the holotype speciemen (Fig. 1I; Table 1) and several paratype specimens stained with protargol and silver nitrate (registration number SP–2004–0624–02), respectively, have been deposited in the Laboratory of Protozoology, Ocean University of China, China. Description: Cell inverted bell-shaped, measuring 35–40 m × 35–45 m in vivo, ratio of length to width ca. 1:1, maximum width at peristomial lip (Fig. 1A and H; Table 1). Peristomial lip relatively thin, well extended and body not constricted beneath it. Peristomial disk flat and moderately elevated when cell fully extended. Pellicle smooth at low magnification, while pellicular protuberances clearly visible above 1000× magnification (Fig. 1G, H and K). Cytoplasm colorless or slightly grayish, and some well fed cells packed with many grayish food granules or vacuoles (Fig. 1A and H). Single large contractile vacuole apically located (Fig. 1A). Macronucleus long, J-shaped, with its semicircular oral arm orienting transversely to long axis and locating immediately below the peristome (Fig. 1A). Macronucleus extended aborally from oral end and recurved, forming bottom of “J”. Micronucleus not observed. Stalk approximately 140–180 m long, 4 m in diameter and surface of stalk usually smooth (Fig. 1C–E). Spasmoneme approximately 2 m in diameter, with 0.4 m, grayish thecoplasmic granules sparsely distributed on it (Fig. 1F; Table 1). Oral infraciliature as shown in Fig. 1B. Haplokinety and polykinety completing approximately one circuit together around peristome and continuing into infundibulum, where they separated and made another complete circuit on opposite walls of the passageway before ending at or near the cytostome (Fig. 1B). Polykinety 1 accompanied by two additional polykineties in infundibulum. Each of these infundibular polykineties composed of three rows of
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Fig. 1. A–K. Morphology of Pseudovorticella dingi nov. spec. from life (A, C–H, K) and after impregnation with protargol (B, I) and silver nitrate (J). A, H: Typical zooids at high magnification, arrowheads show pellicular granules. B: Oral infraciliature, arrowhead marks the epistomial membrane, arrow with numerals indicates numbering convention for polykineties and rows of kinetosomes within each polykinety. C–E: Individuals at low magnification. F: Detail of stalk, arrows indicate thecoplasmic granules. G, K: Living zooids at high magnification focused to show the pellicular granules (arrowheads). I: Detailed arrangement of infundibular polykineties. J: Zooid at high magnification focused to show partial silverline system, arrowheads and arrows indicate the trochal band and pellicular pores, respectively. G, germinal kinety; H, Haplokinety; P1–3, infundibular polykinety 1–3; Po, polykinety. Scale bars = 25 m.
kinetosomes spreading sufficiently far apart to be distinct. Adstomal ends of rows in polykinety 1 terminating at slightly different levels; rows 2 and 3 slightly longer than row 1 in polykinety 1. Polykinety 2 terminating between and above adstomal ends of polykinety 1 and polykinety 3. Row 1 conspicuously shorter than rows 2 and 3 in polykinety 3 (Fig. 1B and I); Abstomal end of row 1 clearly separated from the other two, whose adstomal end is near the cytostome at a similar level as rows 2 and 3 of polykinety 1 (Fig. 1I). Germinal kinety lying parallel to the haplokinety within upper half of infundibulum (Fig. 1B). Epistomial membrane short and locating near opening of infundibulum (Fig. 1B). Trochal band composed of a zigzag structure of kinetosomes encircling cell near aboral end (Fig. 1J). Silverline system typical of genus, 28–36 transverse silverlines between peristome and trochal band, and 13–18 between trochal band and scopula. Pellicular pores associated with silverlines observed at high magnification (Fig. 1J; Table 1). Remarks and comparison: Vorticella granulata Kahl, 1933 resembles the new species and comparison should
be made between them. The infraciliature and silverline system of V. granulata have not been described yet. However, Pseudovorticella dingi differs from V. granulata by the combination of the following characters: (1) body shape (inverted-bell shaped vs. elongated bell-shaped); (2) body size (35–40 m vs. 50–60 m); (3) position of contractile vacuole (apically located within peristomial disc vs. dorsally located near infundibulum); (4) appearance of peristomial lip (extended vs. narrow); (5) shape of macronucleus (J-shaped vs. C-shaped) (Fig. 3B and D; Table 2; Kahl 1933). Regarding body shape, Pseudovorticella dingi should also be compared with P. sphagni Foissner and Schiffmann, 1974 (Fig. 3C) and P. jaerae (Precht, 1935) Sun et al., 2009 (Fig. 3A). Pseudovorticella sphagni is a freshwater species and has two contractile vacuoles and fewer silverlines, thus, it cannot be confused with P. dingi (Foissner and Schiffmann 1974). Pseudovorticella jaerae is separated from P. dingi by its ventrally located contractile vacuole (vs. apically located) and fewer silverlines (20–26, 8–11 vs. 28–36, 13–18; Table 2; Sun et al., 2009).
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Table 1. Morphometric characterization of Pseudovorticella dingi nov. spec., P. wangi nov. spec., P. plicata, P. banatica, and P. anomala. Charactera
Species
Min
Max
Mean
Body length in vivo
P. dingi P. wangi P. plicata P. banatica P. anomala
35 45 80 70 35
40 60 90 80 40
37.5 53.2 84.0 76.0 38.0
1.6 4.7 3.7 3.3 2.1
20 20 10 9 12
Body width in vivo
P. dingi P. wangi P. plicata P. banatica P. anomala
35 30 40 60 30
45 45 45 70 40
41.5 38.3 41.2 62.2 36.0
2.5 4.6 1.9 3.7 0.8
20 20 10 9 12
Width of peristomial lip
P. dingi P. wangi P. plicata P. banatica P. anomala
54 44 47 64 29
58 47 51 66 31
56.4 45.7 49.6 65.0 30.3
1.3 1.0 1.1 0.8 0.7
20 20 20 20 20
Thickness of peristomial lip
P. dingi P. wangi P. plicata P. banatica P. anomala
4 6 6 5 4
5 7 7 6 5
4.6 6.5 6.4 5.5 4.6
0.5 0.5 0.5 0.5 0.4
20 20 20 20 20
Length of stalk
P. dingi P. wangi P. plicata P. banatica P. anomala
140 150 280 380 50
180 250 360 500 80
163.1 216.7 323.9 422.3 66.0
11.9 30.7 26.8 37.2 8.5
18 16 11 13 11
Width of stalk
P. dingi P. wangi P. plicata P. banatica P. anomala
4 5 5 6 3
4 6 7 8 4
4 5.6 6.2 6.6 3.3
0.0 0.5 0.9 0.6 0.5
18 16 11 13 11
Width of Spasmoneme
P. dingi P. wangi P. plicata P. banatica P. anomala
2 2 2 3 2
2 3 3 4 2
2.0 2.6 2.5 3.0 2.0
0.0 0.5 0.5 0.2 0.0
18 16 11 13 11
Number of silverlines from peristome to trochal band
P. dingi P. wangi P. plicata P. banatica P. anomala
28 17 41 35 34
36 20 46 39 39
31.7 18.4 43.4 37.2 35.8
2.9 1.1 2.0 1.4 1.6
6 7 5 7 7
Number of silverlines from trochal band to scopula
P. dingi P. wangi P. plicata P. banatica P. anomala
13 9 14 12 16
18 11 17 16 19
16.2 10.1 14.8 14.2 17.5
2.1 0.8 1.1 1.3 1.3
5 8 6 6 6
SD
n
a Data based on live observation and silver-impregnated specimens. Measurements in m. Abbreviations: Max, maximum; Mean, arithmetic mean; Min, minimum; n, sample number; SD, standard deviation.
Pseudovorticella wangi nov. spec. (Fig. 2A–J; Table 1) Diagnosis: Marine Pseudovorticella. Cell elongate, trumpet-shaped, measuring 50 m × 40 m in vivo with a relatively broad, flat peristomial lip about 45 m across, below which body slightly constricted. Two small contractile
vacuoles ventrally located. Macronucleus J-shaped. Transverse silverlines numbering 17–20 from peristome to trochal band, 9–11 from trochal band to scopula. Polykinety 3 consisting of three rows, with abstomal end of row 1 of polykinety 3 diverging from the other two and ending alongside row 3
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Table 2. Comparison of Pseudovorticella dingi nov. spec. with morphologically similar species. Character
P. dingi
Vorticella granulata
P. sphagni
P. jaerae
Body size in vivo (m) Body shape Number and position of contractile vacuole Appearance of peristomial lip Macronucleus Number of silverlines above and below trochal band Habitat Data source
35–40 × 35–45 Inverted bell 1, apical Extended J-shaped 28–36; 13–18 Marine Present study
50–60 in length Elongate 1, dorsal Narrow C-shaped –; – Freshwater Kahl (1935)
40–50 in length Inverted bell 2, ventral and dorsal Relatively extended J-shaped 26–27; 8–10 Freshwater Foissner (1979)
40–55 × 25–45 Inverted bell 1, dorsal Relatively extended J-shaped 20–26; 8–11 Marine Sun et al. (2009)
“–”, data is not available.
of polykinety 2. Adstomal end of rows 2 and 3 of polykinety 3 prolonging and converging with row 3 of polykinety 1. Type locality: Haibo Bridge, Qingdao, China (36◦ 08 94 N; 120◦ 37 16 E). Dedication: We name this new species in honor of Prof. Jianguo Wang, Institute of Hydrobiology, China, who has
made great contributions to the field of parasitic protozoology. Deposition of slides: The protargol slide (registration number SP–05–0408–01) containing the holotype specimen (Fig. 2H; Table 1) and several paratype specimens stained with protargol and silver nitrate (registration number
Fig. 2. A–J. Pseudovorticella wangi nov. spec. from life (A, C–F, I, J) and after impregnation with protargol (B, H) and silver nitrate (G). A, D: Typical individuals at low magnification. B: Entire oral infraciliature in dorsal view, arrow with numerals indicates numbering convention for polykineties and rows of kinetosomes within each polykinety, and arrowhead marks epistomial membrane. C, F: Living zooids at high magnification. E: Living zooid at high magnification focused to show the pellicular striations. G: Partial silverline system, arrowheads mark pellicular pores. H: Detailed arrangement of infundibular polykineties. I, J: Zooids at high magnification indicating the two small contractile vacuoles (arrows and arrowheads). G, germinal kinety; H, Haplokinety; P1–3, infundibular polykinety 1–3; Po, polykinety. Scale bars = 30 m.
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Fig. 3. A–H. Living morphology of some species which are similar to the new species described in present study. A: Ventral view of Pseudovorticella jaerae (from Sun et al., 2009). B, D: Ventral view of Vorticella granulata (from Kahl 1935). C: Pseudovorticella sphagni (from Foissner 1979). E: Dorsal view of Pseudovorticella pseudocampanula (from Foissner 1979). F: Ventral view of Pseudovorticella bidulphiae (from Ji et al., 2011). G: Ventral view of Pseudovorticella mutans (from Foissner 1979). H: Pseudovorticella monilata (from Foissner 1979). Scale bars = 40 m.
SP–05–0408–02), respectively, have been deposited in the Laboratory of Protozoology, Ocean University of China, China. Description: Cell 45–60 × 30–45 m, elongated bellshaped (Table 1). Peristomial lip relatively thin, flat and well extended and body slightly constricted beneath it. Peristomial disc flattened and slightly obliquely elevated when cell fully extended (Fig. 2C and F). Pellicle striations could be seen above 400× magnification (Fig. 2E), but surface of cell completely smooth at low magnifications. Oral cilia relatively long and rather stiff (Fig. 2C, D and F).
Cytoplasm grayish and usually containing several yellow greenish food granules 4–12 m in diameter. Two small contractile vacuoles near ventral wall of infundibulum, one located aborally to mid body near middle part of relative short, broad infundibulum, the other located near end of infundibulum at almost same level as anterior one (Fig. 2I and J). In the habitat water in which they were maintained, contractile vacuoles discharging at different rates: the anterior one approximately once a minute, the posterior one approximately once every two minutes. Macronucleus J-shaped with aboral end slightly recurved (Fig. 2C). Micronucleus not observed.
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Stalk measuring approximately 3–5 times the length of cell body and 6 m across (Fig. 2A and D; Table 1). Spasmoneme 2–3 m in diameter with numerous, grayish thecoplasmic granules 0.3–0.5 m in diameter. Oral infraciliature as shown in Fig. 2B and H. Haplokinety and polykinety both making one and one–third turns before entering infundibulum, where they made a further turn. All polykineties consisting of three rows of kinetosomes in lower half of infundibulum. Infundibular polykinety 1 and polykinety 2 longer than polykinety 3. Three rows of polykinety 1 being of almost equal length and terminating at end of infundibulum. Adstomal ends of rows in polykinety 1 terminating at slightly different levels. Adstomal ends of polykinety 2 terminating between polykinety 1 and polykinety 3 and abstomally far to their adstomal ends. Polykinety 1 separated from polykinety 2 by small gap (Fig. 2B and H). Row 1 of polykinety 3 conspicuously shorter than the other two and displaced adstomally for a short distance relative to the other two. Haplokinety passing around infundibulum on wall opposite to polykinety. Germinal kinety lying parallel to upper half of haplokinety (Fig. 2B). Epistomial membrane located near opening of infundibulum as commonly seen in other peritrichs (Fig. 2B). Silverline system reticulate with 17–20 transverse silverlines from peristome to trochal band and 9–11 transverse silverlines between trochal band and scopula. Many pellicular pores sparsely distributed among silverlines (Fig. 2G; Table 1). Remarks and comparison: Pseudovorticella bidulphiae (Stiller, 1939) Ji et al. in Sun et al. (2009) bears a strong resemblance to the new form in terms of body shape, the presence of two contractile vacuoles and its marine habitat. Pseudovorticella bidulphiae, however, has a relatively small size (30–40 vs. 45–60 m), a higher number of silverlines between the peristome and the trochal band (25–31 vs. 17–20) and different structures in polykinety 3 (with only two rows vs. three rows) (Fig. 3F; Table 3; Sun et al., 2009). In regard to its general appearance, the new species should also be compared with three congeners, P. monilata (Tatem, 1870) Foissner and Schiffmann, 1974, P. mutans (Penard, 1922) Foissner, 1979 and P. pseudocampanula Foissner, 1979. Pseudovorticella monilata also has two contractile vacuoles and a J-shaped macronucleus. However, the former is a freshwater species and has a relatively large body size (60–70 vs. 45–60 m) and more silverlines from the trochal band to the scopula (9–18 vs. 9–11) (Fig. 3H; Table 3; Foissner 1979; Foissner et al., 1992). Pseudovorticella mutans (Fig. 3G) and P. pseudocampanula (Fig. 3E) can be distinguished from P. wangi by their habitat (freshwater vs. marine) and the number of contractile vacuoles (1 vs. 2) (Table 3; Foissner 1979).
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Pseudovorticella plicata (Gourret and Roeser, 1886) Sun, Ji, Warren and Song, 2009 (Fig. 4A–J; Table 1) Deposition of slides: One protargol preparation (registration number SP–2005–0618–01) and one silver nitrate preparation (registration number SP–2005–0618–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have already been documented by Sun et al. (2009) (Fig. 4A–E). In this study, we further noted that the cell was not constricted below a relatively broad peristomial lip which had many closely spaced frills that could be observed in vivo under high magnification (Fig. 4I, arrows; Table 1). Telotroch (swarmer) roughly cylindrical, 60 m × 35 m in size (Fig. 4C). Stalk 280–360 m long, relatively thick, 5–7 m wide. Spasmoneme 2–3 m in diameter, with numerous, 0.8–1.2 m, dark gray thecoplasmic granules along its length (Fig. 4J; Table 1). Infraciliature and silverline system as shown in Fig. 4F–H. Trochal band composed of double rows of kinetosomes (Fig. 4B). Silverline system typical of genus, pellicular striae closely spaced, with many pellicular pores sparsely distributed (Fig. 4G and H).
Pseudovorticella banatica (Lepsi, 1947) Sun, Ji, Warren and Song, 2009 (Fig. 4K–T; Table 1) Deposition of slides: One protargol preparation (registration number SP–2005–1016–01) and one silver nitrate preparation (registration number SP–2005–1016–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have already been documented by Sun et al. (2009) (Fig. 4K–N and P–R). In our observations we further noted that the peristomial disc was large and highly elevated above a thin, single layered peristomial lip which was usually the widest part of the cell, measuring about 64–66 m in diameter (Fig. 4Q and R; Table 1). Stalk usually five times length of zooid, but can be up to 500 m long, typically 6–8 m across (Fig. 4K and L). Spasmoneme 3–4 m across, with numerous, conspicuous, dark gray thecoplasmic granules, approximately 0.8 m across (Fig. 4N; Table 1). Infraciliature and silverline system as shown in Fig. 4S and T. Trochal band composed of double rows of kinetosomes encircling cell at approximately one third of body length from
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Fig. 4. A–T. Photomicrographs of Pseudovorticella plicata (A–J) and P. banatica (K–T) from life (A–E, I–R) and after protargol (F, S) and silver nitrate (G, H, T) impregnation. A, B: Zooids at low magnification, arrow indicates trochal band. C: Telotroch. D: Zooid at high magnification to show pellicular striations. E: Zooid at high magnification. F: Detailed arrangement of infundibular polykineties. G, H: Partial silverline system. I: Zooid at high magnification focused to show frills on peristomial lip (arrows). J: Detail of stalk, arrows indicate thecoplasmic granules. K, L, P: Individuals at low magnification. M, Q, R: Zooids at high magnification. N: Detail of stalk, arrows indicate granules. O: Living zooid at high magnification focused to show the pellicular striations. S: Detail of infundibular polykineties. T: Silverline system. P1–3, infundibular polykinety 1–3. Scale bars = 50 m.
P. Sun et al. / European Journal of Protistology 49 (2013) 467–476
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Table 3. Comparison of Pseudovorticella wangi nov. spec. with morphologically similar species. Character
P. wangi
P. bidulphiae
P. monilata
P. mutans
P. pseudocampanula
Body size in vivo (m) Body shape Number and position of contractile vacuole Number of silverlines above and below trochal band Structure of polykinety 3 Habitat Data source
45–60 × 30–45 Elongate 2, ventral
30–40 × 35–40 Elongate 2, ventral
60–70 in length Elongate 1, ventral
65–95 in length Conical 1, ventral
32–50 in length Conical 1, ventral
17–20; 9–11
25–31; 9–13
19–23; 9–18
24–28; 16–19
28–33; 16–18
Three rows Marine Present study
Two rows Marine Sun et al. (2009)
Three rows Freshwater Foissner et al. (1992)
–; – Freshwater Foissner (1979)
–; – Freshwater Foissner (1979)
“–”, data is not available.
scopula. Silverline system typical of genus, and pellicular striae widely spaced with pellicular pores sparsely distributed (Fig. 4O and T). Pseudovorticella anomala (Gourret and Roeser, 1886) Sun, Ji, Warren and Song, 2009 (Fig. 5A–I; Table 1) Deposition of slides: One protargol preparation (registration number SP–2004–0508–01) and one silver nitrate preparation (registration number SP–2004–0508–02) have been deposited as voucher slides in the collection of the Laboratory of Protozoology, OUC, China. Supplementary description: The cell shape and size, and the number and the position of contractile vacuoles have
already been documented by Sun et al. (2009) (Fig. 5A–E). In our study we further observed that the body was constricted deeply beneath a narrow, relatively thick peristomial lip which measured 29–31 m in diameter (Table 1). Peristomial disk extremely flat and slightly elevating above peristomial lip (Fig. 5A–C and E). Telotroch (swarmer) which was also not mentioned in Sun et al. (2009), roughly spherical and about 30 m × 25 m in size (Fig. 5D). Stalk short, approximately 50–80 m long and relatively thin, 3–4 m wide. Spasmoneme 2 m in diameter, with gray thecoplasmic granules 0.3–0.4 m sparsely distributed along its length (Fig. 5A–C; Table 1).
Fig. 5. A–I. Photomicrographs of Pseudovorticella anomala from life (A–E) and after silver nitrate (F) and protargol (G–I) impregnation. A–D: Individuals at low magnification, arrow in (D) shows the forming telotroch. E: A typical zooid at high magnification. F: Partial silverline system, arrowheads indicate trochal band. G–I: General oral infraciliature. Ma, macronucleus; P1–3, infundibular polykinety 1–3. Scale bars = 50 m.
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Infraciliature and silverline system as shown in Fig. 5F–I. Trochal band composed of double rows of kinetosomes encircling cell at approximately one third of body length from scopula (Fig. 5F). Silverline system typical of genus, and pellicular striae closely spaced with pellicular pores sparsely distributed (Fig. 5F).
Acknowledgements This work was supported by the Natural Science Foundation of China (project no. 31272285; 41276139, RCN-BC31111120437), Basic Science Research Program through the NRF funded by the Government of Korea (MEST) (no. 2012R1A1A2005751; M.K. Shin), and King Saud University, Deanship of Scientific Research, Research Group Project (no. RGP-VPP-083; K.A.S. Al-Rasheid). We appreciate the comments of two anonymous reviewers and associate editor, which greatly improved the manuscript.
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