Acta Protozoologica

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Two New and Two Poorly Known Species of Ancistrum (Ciliophora, Scuticociliatia, Thigmotrichida) Parasitizing Marine Molluscs from Chinese Coastal Waters of the Yellow Sea

Publication date: 13.07.2015

Acta Protozoologica, 2015, Volume 54, Issue 3, pp. 195 - 208



Kuidong Xu
Chinese Academy of Sciences, Institute of Oceanology, Qingdao, China
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Weibo Song
Institute of Evolution and Marine Biodiversity & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
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Alan Warren
Department of Zoology, Natural History Museum, Cromwell Road, London, UK
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The morphology and taxonomy of two new and two poorly known ciliate species of Ancistrum, found in the mantle cavity (mainly on gills) of marine molluscs from culture beds and pools along the Chinese coast of the Yellow Sea, were investigated using living observation and silver impregnation. Ancistrum haliotis n. sp. was isolated from the abalone Haliotis discus hannai Ino, A. crassum Fenchel, 1965 from the purple clam Saxidomus purpuratus (Sowerby), A. acutum n. sp. from the surf clam Mactra veneriformis Reeve, and A. japonicum Uyemura, 1937 from both the venus clam Cyclina sinensis (Gmelin) and from Dosinia japonica (Reeve). Ancistrum haliotis differs from its most similar relative A. mytili (Quennerstedt, 1867) by the body outline (anterior portion narrower vs. wider than the posterior portion), the macronuclear shape (broadly ellipsoidal vs. reniform or sausage-like), and by having fewer somatic kineties (28–32 vs. usually more than >40). Ancistrum crassum is characterized by the naked area at the apical end of the cell, the relatively short buccal field occupying about two thirds of the body length, and the posterior-dorsal cone-shaped prolongation. Ancistrum acutum n. sp. and A. japonicum are almost identical in morphometry, but differ distinctly in the live morphology (anterior end pointed and posterior end rounded vs. anterior end narrowly rounded and posterior-dorsal end protruded) and ciliary pattern (all right-side kineties extend to posterior body end vs. all right-side kineties excluding somatic kinety 1 distinctly shortened posteriad, forming a glabrous zone). We neotypify Ancistrum japonicum and discuss the taxonomic status of the four species. Based on an evaluation of all nominal species of Ancistrum and Ancistrumina, we recognize nine valid species of Ancistrum and provide a tabular guide to their identification. Fenchelia Raabe, 1970 is regarded as a junior synonym of Ancistrum Maupas, 1883. We synonymize Ancistrumina nucellae Khan, 1970 with Ancistrum japonicum Uyemura, 1937 and Ancistrum edajimanum Oishi, 1978 with A. crassum Fenchel, 1965.



Berger J., Hatzidimitriou G. (1978) Multivariate morphometric analyses of demic variation in Ancistrum mytili (Ciliophora: Scuticociliatida) commensal in two mytilid pelecypods. Protistologica 14: 133–153

Chatton E., Lwoff A. (1949) Recherches sur les ciliés thigmotriches. I. Arch. Zool. Exp. Gén. 86: 169–253

Corliss J. O. (1961) The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature. Pergamon Press, London and New York

Corliss J. O. (1979) The Ciliated Protozoa: Characterization, Classification and Guide to the Literature, 2nd ed. Pergamon Press, New York

Fan X., Hu X., Al-Farraj S. A., Clamp J. C., Song W. (2011) Morphological description of three marine ciliates (Ciliophora, Scuticociliatia), with establishment of a new genus and two new species. Eur. J. Protistol. 47: 186–196

Fenchel T. (1964) On Ancistrum caudatum sp. nov. and Hypocomides modiolariae Chatton and Lwoff (Ciliata, Thigmotrichida) from the lamellibranch Musculus niger (Gray). Ophelia 
1: 113–120

Fenchel T. (1965) Ciliates from Scandinavian molluscs. Ophelia 
2: 71–174

Foissner W. (1991) Basic light and scanning electron microscopic methods for taxonomic studies of ciliated protozoa. Europ. J. Protistol. 27: 313–330

Gao F., Katz L. A., Song W. (2012a) Insights into the phylogenetic and taxonomy of philasterid ciliates (Protozoa, Ciliophora, Scuticociliatia) based on analyses of multiple molecular markers. Mol. Phylogen. Evol. 64: 308–317

Gao F., Fan X., Yi Z., Strüder-Kypke M., Song W. (2010) Phylogenetic consideration of two scuticociliate genera, Philasterides and Boveria (Protozoa, Ciliophora) based on 18S rRNA gene sequences. Parasitol. Intern. 59: 549–555

Gao F., Strüder-Kypke M. C., Yi Z., Miao M., Al-Farraj S. A., Song W. (2012b) Phylogenetic analysis and taxonomic distinction of six genera of pathogenic scuticociliates (Protozoa, Ciliophora) inferred from sequences of the small subunit rRNA gene. Int. J. Syst. Evol. Microbiol62: 246–256

Hatzidimitriou G., Berger J. (1977) Morphology and morphogenesis of Ancistrum mytili (Scuticociliatida: Thigmotrichina), a commensal ciliate of mytilid pelecypods. Protistologica 13: 477–495

ICZN (The International Commission on Zoological Nomenclature) (1999) International Code of Zoological Nomenclature. International Trust for Zoological Nomenclature, London

Issel D. R. (1903) Ancistridi del Golfo di Napoli. Mitt. Zool. Sta. Neapel16: 65–108

Kahl A. (1931) Urtiereoder Protozoa. I: Wimpertiere oder Ciliata (Infusoria). 2. Holotricha. Tierwelt Dtl. 21: 181–398

Kent W. S. (1880–1882) A manual of the Infusoria (Vol. I–III). David Bogne, London

Khan M. A. (1970) On the morphology and biology of a new arhynchodine thigmotrichid ciliate (Protozoa) from the dog whelk Nucella lapillusJ. Zool. Lond161: 39–47

Kidder G. W. (1933) On the genus Ancistruma Strand (Ancistrum Maupas) I. The structure and division of A. mytili Quenn. and A. isseli Kahl. Biol. Bull. 64: 1–20

Lynn D. H. (2008) The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature, 3rd ed. Springer, Dordrecht

Miao M., Wang Y., Song W., Clamp J. C., Al-Rasheid K. A. S. (2010) Description of Eurystomatella sinica n. gen., n. sp., with establishment of a new family Eurystomatellidae n. fam. (Protista, Ciliophora, Scuticociliatia) and analyses of its phylogeny inferred from sequences of the small-subunit rRNA gene. Int. J. Syst. Evol. Microbiol60: 460–468

Oishi T. (1978) On a new ciliate, Ancistrum edajimanum n. sp., from a bivalve, Tapes philippinarum (Adams et Reeve). Proc. Jap. Soc. Syst. Zool14: 1–4

Pan X., Zhu M., Ma H., Al-Rasheid K. A. S., Hu X. (2013) Morphology and small-subunit rRNA gene sequences of two novel marine ciliates, Metanophrys orientalis spec. nov. and Uronemella sinensis spec. nov. (Protista, Ciliophora, Scuticociliatia), with an improved diagnosis of the genus UronemellaInt. J. Syst. Evol. Microbiol63: 3515–3523

Quennerstedt A. (1867) Bidrag till Sveriges Infusorie fauna. II. Acta Univ. Lund. 4: 1–47

Raabe Z. (1936) Wietere Untersuchungen an parasitischen Ciliaten aus dem polnischen Teil der Ostsee. I. Ciliata Thigmotricha aus den Familien: Thigmophryidae, Conchophthiridae und Ancistrumidae. Ann. Mus. Zool. Pol. 11: 419–442

Raabe Z. (1959) Recherchessur les ciliés thigmotriches (Thigmotricha Ch. Lw.). VI. Sur les genres AncistrumaAncistrinaet les genres voisins. Acta Parasitol. Polonica 7: 215–247

Raabe Z. (1967) OrdoThigmotricha (Ciliata – Holotricha) I. Acta Protozool. 5: 1–36

Raabe Z. (1970) Ordo Thigmotricha (Ciliata – Holotricha) II. Familia Hemispeiridae. Acta Protozool. 7: 117–180

Song W. (2000) Morphological and taxonomical studies on some marine scuticociliates from China sea, with description of two new species, Philasterides armatalis sp. n. and Cyclidium varibonneti sp. n. (Protozoa: Ciliophora: Scuticociliatida). Acta Protozool39: 295–322

Song W., Zhao Y., Xu K., Hu X., Gong J. (2003) Pathogenic Protozoa in Mariculture. Science Press, Beijing (in Chinese)

Uyemura M. (1937) Studies on ciliates form marine mussels in Japan 1. A new ciliate, Ancistruma japonicaSci. Rep. Tokyo Bunr. Daig. B. 3: 115–125

Wilbert N. (1975) Eine verbesserte Technik der Protargolimprägnation für Ciliaten. Mikrokosmos 64: 171–179

Xu K., Song W. (1999) Pathogenetic ciliates from mariculture waters. In: Progress in Protozoology (Eds. W. Song et al.), Ocean University Press, Qingdao (in Chinese)

Xu K., Song W. (2003) Parasitic ciliates of cultured molluscs. In: Pathogenic Protozoa in Mariculture (Eds. W. Song et al.), Science Press, Beijing (in Chinese)

Xu K., Meng F., Cao J., Song W. (1997) Morphological studies on the thigmotrichine ciliate, Ancistrum crassum Fenchel, 1965 on the gills of short-necked clam. J. Ocean Univ. Qingdao 27: 466–470 (in Chinese with English abstract)


Information: Acta Protozoologica, 2015, pp. 195 - 208

Article type: Original research article


Chinese Academy of Sciences, Institute of Oceanology, Qingdao, China

Institute of Evolution and Marine Biodiversity & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China

Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China

Department of Zoology, Natural History Museum, Cromwell Road, London, UK

Published at: 13.07.2015

Article status: Open

Licence: None

Percentage share of authors:

Kuidong Xu (Author) - 33%
Weibo Song (Author) - 33%
Alan Warren (Author) - 34%

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