Morphology and Phylogeny of Four New Vorticella Species (Ciliophora: Peritrichia) from Coastal Waters of Southern China

Four new species of Vorticella, V. parachiangi sp. n., V. scapiformis sp. n., V. sphaeroidalis sp. n., and V. paralima sp. n., were isolated from coastal brackish waters of southern China. Their morphology, infraciliature, and silverline system were investigated based on observations of specimens both in vivo and following silver staining. Vorticella parachiangi sp. n. is distinguished by: a J‐shaped macronucleus; a single dorsally located contractile vacuole; a two‐rowed infundibular polykinetid 3, in which row 1 is shorter than row 2; 21–31 silverlines between peristome and aboral trochal band, 6–11 between aboral trochal band and scopula. Vorticella scapiformis sp. n. is characterized by its conspicuously thin and irregularly edged peristomial lip; a J‐shaped macronucleus; a single, ventrally located contractile vacuole; row 1 of the infundibular polykinetid 3 proximally shortened; 18–25 silverlines between peristome and aboral trochal band, 8–12 between aboral trochal band and scopula. Vorticella sphaeroidalis sp. n. can be identified by its small, sub‐spherical zooid; a C‐shaped macronucleus; a ventrally located contractile vacuole; an aboral trochal band adjacent to the scopula; 16–18 silverlines between persitome and aboral trochal band, two between aboral trochal band and scopula. Vorticella paralima sp. n. can be identified by its ovoidal zooid; a J‐shaped macronucleus; a dorsally positioned contractile vacuole; rows 1 and 2 of the infundibular polykinetid 3 proximally shortened; 26–35 silverlines from peristome to aboral trochal band, and 7–13 from aboral trochal band to scopula. The SSU rDNA genes of these four species were sequenced and their phylogeny was analyzed.     

Taxonomic characterization of two marine peritrichous ciliates, Epicarchesium corlissi n. sp. and Pseudovorticella jiangi n. sp. (Ciliophora: Peritrichia), from northern China

Two new marine peritrich ciliates, Epicarchesium corlissi n. sp. and Pseudovorticella jiangi n. sp., were discovered in mariculture waters on the coast of northern China near Qingdao. Their morphology, infraciliature and silverline system were investigated based on both living and silver-impregnated specimens. E. corlissi is characterized as follows: marine Epicarchesium with dichotomously branched stalk; zooids elongate, approximately 60–70×25–35 μm in vivo; peristomial collar double-folded; macronucleus J-shaped; single, small contractile vacuole ventrally positioned; more than 60 striations between peristome and aboral trochal band, 13–18 from aboral trochal band to scopula; abstomal end of row 1 of infundibular polykinety 3 terminating at same level as rows 2 and 3 of infundibular polykinety 3; rows 2 and 3 of infundibular polykinety 3 much longer than row 1 and converging adstomally with infundibular polykinety 1. The new species P. jiangi is diagnosed as follows: marine Pseudovorticella; zooid inverted bell-shaped, approximately 80×60 μm in vivo and with a broad, flat, thin peristomial collar that measures approximately 90 μm across; pellicle with transparent cortical vesicles; macronucleus J-shaped; number of silverlines between peristome and aboral trochal band 20–24, from aboral trochal band to scopula 9–11; abstomal end of row 1 of infundibular polykinety 3 diverges from the other two rows of this polykinety and ends alongside row 3 of infundibular polykinety 2.     

Description of Zoothamnium foissneri n. sp. and redescription of Z. duplicatum Kahl, 1933 and Z. mucedo Entz, 1884, three species of marine peritrichous ciliates

Three marine peritrichs, Zoothamnium foissneri n. sp., Z. duplicatum Kahl, 1933 and Z. mucedo Entz, 1884, were isolated from the littoral area of Qingdao, China. The morphology, infraciliature and silverline system were studied on living and silver-impregnated specimens. Z. foissneri is distinguished from congeners by its slender zooid shape, size, appearance of peristomial border, the form of peniculus 3, colony form and habitat. Based on the Qingdao populations, supplementary information is given for two known species showing that Z. duplicatum can be distinguished by the zooid shape and size, the number of silverlines between the aboral trochal band and the scopula, and the form of peniculus 3, while Z. mucedo can be distinguished from other species of similar zooid shape and size by the form of peniculus 3 and the number of silverlines between the oral area and the aboral trochal band.     

Morphology and Phylogeny of Three Pseudovorticella Species (Ciliophora: Peritrichia) from Brackish Waters of China

The biodiversity of peritrich ciliates from brackish biotopes is rarely investigated, especially members of the genus Pseudovorticella. Here, the morphology of three species of Pseudovorticella, i.e. P. cf. vestita (Stokes, 1883) Jankowski, 1976, P. spathulata sp. n., and P. qinghaiensis sp. n. isolated from brackish waters were studied. Pseudovorticella cf. vestita is characterized by inverted bell‐shaped cell; a J‐shaped macronucleus; a single contractile vacuole ventrally located; P3 three‐rowed; pellicle striated with highly developed pellicular vesicles; 18–22 transverse silverlines between peristome and aboral trochal band, and 9–13 between aboral trochal band and scopula. Pseudovorticella spathulata sp. n. differs from its congeners by the following combination of characters: elongate‐elliptical cell; a single contractile vacuole near ventral wall of infundibulum; a J‐shaped macronucleus; P3 three‐rowed; 24–34 silverlines between oral area and aboral trochal band and 6–10 between aboral trochal band and scopula. Pseudovorticella qinghaiensis sp. n. is characterized by: cell with an oval outline; a single contractile vacuole near ventral wall of infundibulum; a C‐shaped macronucleus; P3 three‐rowed; 30–35 and 9–11 transverse silverlines above and below the trochal band, respectively. The SSU rDNA sequences of five Pseudovorticella species, namely P. annulata, P. monilata, P. parakenti, P. spathulata sp. n., and P. cf. vestita, plus that of Zoothamnium hartwigi, are reported for the first time and their evolutionary relationships are investigated. Five undefined Pseudovorticella forms are considered might be conspecific with P. monilata. Two congeners are conspecific with P. spathulata sp. n. Phylogenetic analyses based on SSU rDNA sequences reveal that Pseudovorticella is not monophyletic and Z. hartwigi clusters with its congeners as expected.     

Description of Opisthonecta Matiensis N. Sp. (Protozoa, Ciliophora), A New Peritrich Ciliate From Wastewater

Opisthonecta matiensis n. sp. was isolated from the inlet water of a wastewater treatment plant near Madrid, Spain, and studied in vivo, with silver methods, and using electronic and indirect immunofluorescence microscopy. This new species shows an amphora-like cell shape and has a size of 45-73 microns (x 58.2) x 25-40 microns (x 31.3). The oral infraciliature is formed by one haplokinety, three polykineties, and a short row of kinetosomes (epistomial membrane). The aboral infraciliature is made up of the trochal band and the scopula. From the trochal band arise three fibrillar systems: oral fibers, aboral fibers, and oblique fibers. The myoneme system is composed of a delicate peristomial ring, longitudinal branched fibers that reach the trochal band and of radial fibers extending from the scopula to the trochal band. The silverline system consists of an average of 147 lines. This new species is separated from other known forms by its smaller size, the presence of one single vacuole, and its higher number of silverlines.     

Two new species of Epistylis (Ciliophora: Peritrichida) on the blue crab (Callinectes sapidus) in the Gulf of Mexico

Two epibiotic peritrichs infested the blue crab, Callinectes sapidus, from the Gulf of Mexico, Mississippi, USA. Epistylis callinectes n. sp. was isolated from the epipods of maxillipeds, bases of gill-cleaning setae, and gills, and Epistylis clampi n. sp. was isolated from the exterior surfaces of the exoskeleton. Epistylis callinectes has short, symmetrically and dichotomously branched stalks; its zooid is elongate ovoid and conspicuously longer than the individual stalk branches, measuring 40-57 (49) x 18-33 (26) microm in vivo and containing a thick, undivided peristomial lip (PL). It has a single contractile vacuole and a transverse horseshoe-shaped macronucleus. Its haplokinety (H) and polykinety (Po) complete one and one-half circuits on the peristome before entering the infundibulum. There is a distal kinetal fragment present at the distal end of both the H and Po. Epistylis callinectes has 48-70 transverse silverlines from the oral area to the trochal band (TB) and 19-26 from the TB to the scopula. Epistylis clampi has long, asymmetrically, and dichotomously branched stalks. Its zooid is elongate vase-shaped, measuring 35-64 (48) x 21-30 (27) microm in vivo and with a thick, transversely folded PL. The stalks supporting zooids are unequal in length. Its zooid has a single contractile vacuole and a transverse horseshoe-shaped macronucleus occurs in the upper half of the body. Its H and Po complete approximately one circuit around the peristome before entering the infundibulum. There is a distal kinetal fragment present at the distal end of both the H and Po. This species has 71-112 transverse silverlines from the peristome to the scopula.     

六种淡水纤毛虫形态学研究

借助活体观察和银染法对6种淡水纤毛虫(纵长板壳虫Coleps elongatus、瓜形原膜袋虫Protocyclidiumcitrullus、亨氏累枝虫Epistylis hentscheli、钟形钟虫Vorticella campanula、长柄球吸管虫Metacineta macrocaulis、四分锤吸管虫Tokophrya quadripatita)的形态和纤毛图式进行了详尽研究。本工作首次描述了亨氏累枝虫、四分锤吸管虫、纵长板壳虫的中国种群,同时揭示了亨氏累枝虫长期未知的纤毛图式特征并给出该种类的新定义: 虫体高钟形,活体大小约(100-130) m(60-65) m; 伸缩泡1个,腹位; 大小核各1枚,大核C型; 群体为规则对称二叉分枝; 口区三片小膜均由三列动基列组成,第三小膜由三列等长的动基列组成,其终止处高于第一小膜下端; 虫体前端到反口纤毛环间的银线约71-74条,反口纤毛环到帚胚间的银线约35-47条; 淡水生境。此外,本研究对长柄球吸管虫、钟形钟虫、瓜形原膜袋虫进行了重新描述,补充了显微照片。     

Rediscovery and redescription of the marine peritrichous ciliate Epicarchesium abrae (Precht, 1935) nov. comb. (Protozoa, Ciliophora, Peritrichia)

The morphology, infraciliature and silverline system of the marine peritrichous ciliate, Epicarchesium abrae (Precht, 1935) nov. comb., isolated from an abalone-farming pond off the coast of Qingdao, China, are investigated. E. abrae is characterized by: size of zooid in vivo 68 μm×48 μm on average; macronucleus usually J-shaped; one dorsally-located contractile-vacuole; colony regularly dichotomously branched with 4–16 zooids; total number of transverse silverlines 62–72, from peristome to aboral ciliary wreath 41–47, from aboral ciliary wreath to scopula 21–25; outer kinety of peniculus 3 prolonged and converges with peniculus 1.     

Observations on Opisthonecta henneguyi Fauré-Fremiet: Infraciliature, Argyrome, and Myonemic System

The infraciliature, argyrome, and myonemic system of Opisthonecta henneguyi have been examined after impregnation with the Fernández-Galiano silver impregnation method. The oral infraciliature is formed by one haplokinety and three polykineties while the aboral infraciliature is formed by the trochal band—six kinetosomes wide—and the scopula. The trochal band has three fibrillar systems: orally directed fibers, aboral fibers, and oblique fibers. The argyrome is formed by 90 to 135 fine circular striations, which cover the whole organism with the exception of the peristome. The myonemic system is located in two regions: the oral and the aboral ones. The oral myonemic system is formed by a fibrous ring which surrounds the peristome underneath the spiral of the peristomial infraciliature and by a group of fibers which depart from the peristomial disc. The aboral myonemic system is much simpler, and it is formed by fibers which extend radially from the scopula. Biometrical characterizations of the vegetative cells and living cysts were also made, and our data are compared with the results obtained previously by other authors.     

Two New Species of Zoothamnium (Ciliophora,Peritrichia) from Korea,with New Observations of Z. parahentscheli Sun et al., 2009

Three peritrichous ciliates, Zoothamnium arcuatum n. sp., Z. grossi n. sp., and Z. parahentscheli Sun et al., 2009, were collected from an estuary of the Taehwagang River, Korea. All these species were investigated based on live observations and silver staining, and their small subunit (SSU) rRNA gene was also sequenced. Zoothamnium arcuatum can be identified by a goblet‐shaped colony, double‐layered peristomial lip, and abstomally shortened row 3 of infundibular polykinety 3 (P3). Zoothamnium grossi is morphologically characterized by an alternately branched stalk with the lowest secondary stalk diverging from the main part of colony, asymmetrically bell‐shaped zooids, and three short, parallel ciliary rows in P3. Phylogenetic analysis revealed that the three Zoothamnium species described in this paper clustered with other members of the family Zoothamniidae, as expected.     

Infraciliature and myoneme system of Campanella umbellaria (Protozoa, Ciliophora, Peritrichida)

The infraciliature and myoneme system of Campanella umbellaria were revealed using the protargol impregnation technique. The main characteristics of the infraciliature are the peristomial ciliary rows (haplokinety and polykineties), which make four and a half turns around the peristomial disc before plunging into the infundibulum, and the aboral infraciliature, which is made up of the aboral ciliary wreath (trochal band) and the scopula. The myoneme system is composed of: 1) longitudinal fibers, which include 60-84 (mean 72.3) short longitudinal fibers, 40-56 (mean 45.8) medium-length longitudinal fibers, and numerous long longitudinal fibers; and 2) circular fibers, which include 8-12 (mean 9.3) peristomial ring fibers, linking fibers, support fibers, and peristomial disc fibers. The various fibers in C. umbellaria are interconnected to form a single myoneme system that may act as a cell skeleton as well as providing the mechanism by which the zooid contracts and relaxes.     

Description of a marine peritrichous ciliate, Pseudovorticella sinensis n. sp. (Ciliophora, Peritrichia) from China

A new marine peritrich ciliate, Pseudovorticella sinensis n. sp. was isolated from a shrimp-farming pond in the littoral area of Qingdao, China. The morphology, infraciliature, and silverline system were studied based on living and silver-impregnated specimens. This species is characterized by (1) an elongated bell-shaped body that measures 50-60 x 35-45 microm in vivo, (2) one large, ventrally located contractile vacuole, and (3) a pellicle covered by a layer of transparent, cortical vesicles. The number of transverse silverlines from the peristomial area to the aboral ciliary wreath is 26-32, and from the aboral ciliary wreath to the scopula is 12-15. The stalk measures about 160-250 microm long x 5-6 microm wide. The spasmoneme has one row of conspicuous thecoplasmic granules, which are about 0.8 microm in diameter.     

Morphology and molecular analyses of four epibiotic peritrichs on crustacean and polychaete hosts,including descriptions of two new species (Ciliophora,Peritrichia)

Four epibiotic sessilid peritrichs, i.e., Zoothamnium wilberti n. sp., Baikalonis microdiscus n. sp., Epistylis anastatica (Linnaeus, 1767) Ehrenberg, 1830, and Rhabdostyla commensalis Möbius, 1888, were isolated from one syllid polychaete and three crustacean hosts in Qingdao, China. For each species, specimens were observed both in vivo and following silver staining. Their SSU rDNA was also sequenced for phylogenetic analyses. Zoothamnium wilberti n. sp. is characterized by the appearance of its colony, which is up to 350 μm high, and usually has fewer than 16 zooids, and the dichotomously branched stalk with transverse wrinkles, the conspicuously conical peristomial disc, and infundibular polykinety 3 comprising three isometric ciliary rows. Baikalonis microdiscus n. sp. can be recognized by its barrel-shaped zooid, small peristomial disc, smooth and short stalk, and its unusual infundibular polykinety 3 comprising a long inner row and a short outer row. Two poorly known species, i.e., Epistylis anastatica and Rhabdostyla commensalis, are redescribed and redefined. Phylogenetic analyses reveal that: (i) R. commensalis is closely related to the family Astylozoidae rather than to the morphologically similar Epistylididae; (ii) B. microdiscus n. sp. is sister to the family Scyphidiidae; (iii) E. anastatica groups with vorticellids and ophrydiids, which further supports the polyphyly of the genus Epistylis; and (iv) Z. wilberti n. sp. is nested within the Zoothamniidae, as expected.     

Pseudovorticella zhengae n. sp., P. difficilis (Kahl, 1933) Jankowski, 1976, and P. punctata (Dons, 1918) Warren, 1987, three marine peritrichous ciliates from north China

The morphology, infraciliature and silverline system of three marine peritrichous ciliates, Pseudovorticella zhengae n. sp., P. difficilis (Kahl, 1933) Jankowski, 1976 and P. punctata (Dons, 1918) Warren, 1987, were investigated by observation in vivo and silver-staining methods. The new species is characterized by its body shape, the appearance of the peristomial lip, the number of transverse silverlines, and the configuration of infundibular polykinety 3; P. difficilis by its body shape, the configuration of infundibular polykinety 3, and unusual annular swellings on the stalk; and P. punctata by the appearance of the pellicle, the configuration of infundibular polykinety 3, and the number of transverse silverlines.     

Taxonomic characterization of two marine peritrichous ciliates, Pseudovorticella clampi n. sp. and Zoothamnium pararbuscula n. sp. (Ciliophora: Peritrichia), from North China

The morphology, infraciliature, and silverline system of two new peritrichous ciliates, Pseudovorticella clampi n. sp. and Zoothamnium pararbuscula n. sp., have been investigated based on both living and silver-impregnated specimens. Partial sequence of 18S-ITS1-5.8S rDNA of Z. pararbuscula is also determined in order to compare it with the closely related congener, Zoothamnium arbuscula. Zoothamnium pararbuscula can be distinguished from its close form Z. arbuscula by the different habitats, the appearance of the main stalk, the position of the contractile vacuole, and the information derived from 18S-ITS1-5.8S rDNA sequence analysis. Pseudovorticella clampi n. sp. is distinguished from its congeners by its body shape and size, pellicle granules, habitat, and number of transverse silverlines.     

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)

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.     

Morphological and Molecular Identification of a New Ciliate,Zoothamnium palmphlatum nov. spec. (Ciliophora,Peritrichia) from North China

A new peritrichous ciliate, Zoothamnium palmphlatum nov. spec., was collected from an estuary in Yantai, China. It was investigated, using both live observation and silver staining. The new species can be identified by a palm‐shaped colony consisting of highly developed and alternately arranged secondary branches, a double‐layered peristomial lip, and an infundibular polykinety 3 composed of two parallel kinetosomal rows. Phylogenetic analyses of the small subunit (SSU) rRNA gene sequence show that Z. palmphlatum clusters with other members of the family Zoothamniidae. Furthermore, the comparison of primary and secondary SSU rDNA structures indicates that Z. palmphlatum is distinctly different from its morphologically similar species (93.2–97.0% in sequence similarity) in combination of H10 and H31 regions. Although Z. palmphlatum shares highest sequence similarity with Zoothamnium mucedo (98.9%), the new species has distinctly different structures in the H11, H12, H18, and H31 regions compared to Z. mucedo, which indicates that sequence similarity may not determine the similarity of the secondary structure.     

Description of a New Freshwater Ciliate Epistylis wuhanensis n. sp. (Ciliophora,Peritrichia) from China,with a Focus on Phylogenetic Relationships within Family Epistylididae

Two populations of Epistylis wuhanensis n. sp., a new freshwater peritrich ciliate, were isolated from different freshwater ponds located in Hubei, China. Their morphological characteristics were investigated using live observation, protargol impregnation, and scanning electron microscopy (SEM). Specimens from the two populations showed identical arrangement of the infraciliature and identical small subunit ribosomal RNA (SSU rRNA) gene and ITS1‐5.8S‐ITS2 sequences. The zooids present bell‐shaped and 90–175 × 27–54 μm in vivo. Macronucleus is variable in shape and located in the middle of cell. Pellicle is usually smooth with 139–154 and 97–105 striations above and below the trochal band, respectively. SSU rRNA gene and ITS1‐5.8S‐ITS2 sequences of E. wuhanensis n. sp. did not match any available sequences in GenBank. Phylogenetically, E. wuhanensis n. sp. clusters with the other Epistylis within the family Epistylididae, but is distinct from the major clades of Epistylis. Above all, the morphological characteristics and molecular analyses support that the present Epistylis is a new species. Expanded phylogenetic analyses of sessilids based on both SSU rRNA gene sequences and ITS1‐5.8S‐ITS2 sequences reveal that the genus Epistylis consists of Epistylis morphospecies and taxonomic revision of the genus is needed.     

蟹累枝虫的光镜及电镜观察

利用活体观察、蛋白银染色及电镜技术对蟹累枝虫(Epistylis eriocheiri)的形态学、表膜下纤维及超微结构进行了较为系统的描述,研究发现:(1)光镜下该种群体双叉分支,活体时虫体表膜柔软,完全伸展时呈长筒状;大核马蹄形,呈横位;伸缩泡单个,斜卧口围缘下方。口围缘纤维上连细密的环状纤维,下接两端较为粗壮,中间细长的纵长纤维,构成了连续的表膜下纤维系。(2)电镜下该种表面具沟、嵴、横纹结构,沟嵴相互交错;口围纤毛花瓣状;虫体表膜层呈齿状,具嵴状突起、泡间微管、表膜孔,胞质层包括内含胞器单一的致密原生质层和富含胞器的疏松原生质层。研究对该种的上述特征在虫体的收缩机制及与其他相似种之间的关系等方面进行了讨论。