Wikipedia

Ciliate

(Redirected fromCiliophora)
This article is about the protozoan phylum Ciliophora. For the type of ciliate cells in general, seeCiliate cells.For the type of leaf margin, seeGlossary of leaf morphology § Edge.

Theciliatesare a group ofalveolatescharacterized by the presence of hair-like organelles calledcilia,which are identical in structure toeukaryotic flagella,but are in general shorter and present in much larger numbers, with a differentundulatingpattern than flagella. Cilia occur in all members of the group (although the peculiarSuctoriaonly have them for part of theirlife cycle) and are variously used in swimming, crawling, attachment, feeding, and sensation.

Ciliate
Temporal range:Ediacaran–Recent
Some examples of ciliate diversity. Clockwise from top left:Lacrymaria,Coleps,Stentor,Dileptus,Paramecium
Scientific classificationEdit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: TSAR
Clade: SAR
Clade: Alveolata
Phylum: Ciliophora
Doflein,1901emend.
Subphyla and classes[1]

See text for subclasses.

Synonyms
  • CiliataPerty, 1852

Ciliates are an important group ofprotists,common almost anywhere there is water—in lakes, ponds, oceans, rivers, and soils, including anoxic and oxygen-depleted habitats.[2]About 4,500 unique free-living species have been described, and the potential number of extant species is estimated at 27,000–40,000.[3]Included in this number are manyectosymbioticandendosymbioticspecies, as well as someobligateandopportunisticparasites.Ciliate species range in size from as little as 10μmin somecolpodeansto as much as 4 mm in length in somegeleiids,and include some of the mostmorphologicallycomplex protozoans.[4][5]

In most systems oftaxonomy,"Ciliophora"is ranked as aphylum[6]under any of severalkingdoms,includingChromista,[7]Protista[8]orProtozoa.[9]In some older systems of classification, such as the influential taxonomic works ofAlfred Kahl,ciliated protozoa are placed within theclass"Ciliata"[10][11](a term which can also refer to agenus of fish). In the taxonomic scheme endorsed by theInternational Society of Protistologists,which eliminates formalrankdesignations such as "phylum" and "class", "Ciliophora" is an unrankedtaxonwithinAlveolata.[12][13]

Cell structure

edit

Nuclei

edit

Unlike most othereukaryotes,ciliates have two different sorts ofnuclei:a tiny,diploidmicronucleus(the "generative nucleus", which carries thegermlineof the cell), and a large,ampliploidmacronucleus(the "vegetative nucleus", which takes care of general cell regulation, expressing thephenotypeof the organism).[14][15]The latter is generated from the micronucleus by amplification of thegenomeand heavy editing. The micronucleus passes its genetic material to offspring, but does not express its genes. The macronucleus provides thesmall nuclear RNAfor vegetative growth.[16][15]

Division of the macronucleus occurs in most ciliate species, apart from those in class Karyorelictea, whose macronuclei are replaced every time the cell divides.[17]Macronuclear division is accomplished byamitosis,and the segregation of thechromosomesoccurs by a process whose mechanism is unknown.[15]After a certain number of generations (200–350, inParamecium aurelia,and as many as 1,500 inTetrahymena[17]) the cell shows signs of aging, and the macronuclei must be regenerated from the micronuclei. Usually, this occurs followingconjugation,after which a new macronucleus is generated from the post-conjugal micronucleus.[15]

Representation of a ciliate
  1. Cilia
  2. Trichocyst
  3. Alveoli, surface cavities or pits
  4. Contractile vacuole,regulates the quantity of water inside a cell
  5. Contractile vacuole pore
  6. Radial canal
  7. Food vacuoles
  8. Lysosome,holds enzymes
  9. Golgi apparatus;modifiesproteinsand sends them out of the cell
  10. Micronucleus
  11. Macronucleus,controls non-reproductive cell functions
  12. Vestibulum
  13. Buccal cavity
  14. Quadrulus
  15. Cytostome,cell mouth
  16. Nascent food vacuole
  17. Acidosome, vesicle involved in the acidification of phagocytes
  18. Waste vacuole
  19. Cytoproct,anal pore for waste ejection
  20. Endoplasmic reticulum,the transport network for molecules going to specific parts of the cell
  21. Mitochondrion,createsATP(energy) for the cell (tubularcristae)
  22. Endosymbionts

Cytoplasm

edit

Food vacuolesare formed throughphagocytosisand typically follow a particular path through the cell as their contents are digested and broken down bylysosomesso the substances thevacuolecontains are then small enough todiffusethrough the membrane of the food vacuole into the cell. Anything left in the food vacuole by the time it reaches the cytoproct (anal pore) is discharged byexocytosis.Most ciliates also have one or more prominentcontractile vacuoles,which collect water and expel it from the cell to maintainosmotic pressure,or in some function to maintain ionic balance. In some genera, such asParamecium,these have a distinctive star shape, with each point being a collecting tube.

Specialized structures in ciliates

edit

Mostly, body cilia are arranged inmono-anddikinetids,which respectively include one and twokinetosomes(basal bodies), each of which may support a cilium. These are arranged into rows calledkineties,which run from the anterior to posterior of the cell. The body and oral kinetids make up theinfraciliature,an organization unique to the ciliates and important in their classification, and include various fibrils andmicrotubulesinvolved in coordinating the cilia. In some forms there are also body polykinetids, for instance, among thespirotrichswhere they generally form bristles calledcirri.

The infraciliature is one of the main components of thecell cortex.Others are thealveoli,small vesicles under the cell membrane that are packed against it to form apelliclemaintaining the cell's shape, which varies from flexible and contractile to rigid. Numerousmitochondriaandextrusomesare also generally present. The presence of alveoli, the structure of the cilia, the form of mitosis and various other details indicate a close relationship between the ciliates,Apicomplexa,anddinoflagellates.These superficially dissimilar groups make up thealveolates.

Feeding

edit

Most ciliates areheterotrophs,feeding on smaller organisms, such asbacteriaandalgae,and detritus swept into the oral groove (mouth) by modified oral cilia. This usually includes a series ofmembranellesto the left of the mouth and a paroral membrane to its right, both of which arise frompolykinetids,groups of many cilia together with associated structures. The food is moved by the cilia through the mouth pore into the gullet, which forms food vacuoles.

Many species are alsomixotrophic,combiningphagotrophyandphototrophythroughkleptoplastyor symbiosis with photosynthetic microbes.[18][19]

The ciliateHalteriahas been observed to feed onchloroviruses.[20]

Feeding techniques vary considerably, however. Some ciliates are mouthless and feed by absorption (osmotrophy), while others are predatory and feed on other protozoa and in particular on other ciliates. Some ciliates parasitizeanimals,although only one species,Balantidium coli,is known to cause disease in humans.[21]

Reproduction and sexual phenomena

edit
Most ciliates divide transversally, but other kinds of binary fission occur in some species.

Reproduction

edit

Ciliates reproduceasexually,by various kinds offission.[17]During fission, the micronucleus undergoesmitosisand the macronucleus elongates and undergoesamitosis(except among theKaryorelicteanciliates, whose macronuclei do not divide). The cell then divides in two, and each new cell obtains a copy of the micronucleus and the macronucleus.

Ciliate undergoing the last processes of binary fission
Division of ciliateColpidium

Typically, the cell is divided transversally, with theanteriorhalf of the ciliate (theproter) forming one new organism, and theposteriorhalf (theopisthe) forming another. However, other types of fission occur in some ciliate groups. These includebudding(the emergence of small ciliated offspring, or "swarmers", from the body of a mature parent);strobilation(multiple divisions along the cell body, producing a chain of new organisms); andpalintomy(multiple fissions, usually within acyst).[22]

Fission may occur spontaneously, as part of the vegetativecell cycle.Alternatively, it may proceed as a result of self-fertilization (autogamy),[23]or it may followconjugation,a sexual phenomenon in which ciliates of compatiblemating typesexchange genetic material. While conjugation is sometimes described as a form of reproduction, it is not directly connected with reproductive processes, and does not directly result in an increase in the number of individual ciliates or their progeny.[24]

Conjugation

edit
Overview

Ciliate conjugation is a sexual phenomenon that results ingenetic recombinationand nuclear reorganization within the cell.[24][22]During conjugation, two ciliates of a compatible mating type form a bridge between theircytoplasms.The micronuclei undergomeiosis,the macronuclei disappear, andhaploidmicronuclei are exchanged over the bridge. In some ciliates (peritrichs,chonotrichsand somesuctorians), conjugating cells become permanently fused, and one conjugant is absorbed by the other.[21][25]In most ciliate groups, however, the cells separate after conjugation, and both form new macronuclei from their micronuclei.[26]Conjugation and autogamy are always followed by fission.[22]

In many ciliates, such asParamecium,conjugating partners (gamonts) are similar or indistinguishable in size and shape. This is referred to as "isogamontic" conjugation. In some groups, partners are different in size and shape. This is referred to as "anisogamontic" conjugation. Insessile peritrichs,for instance, one sexual partner (the microconjugant) is small and mobile, while the other (macroconjugant) is large andsessile.[24]

Stages of conjugation
Stages of conjugation inParamecium caudatum

InParamecium caudatum,the stages of conjugation are as follows (see diagram at right):

  1. Compatible mating strains meet and partly fuse
  2. The micronuclei undergo meiosis, producing four haploid micronuclei per cell.
  3. Three of these micronuclei disintegrate. The fourth undergoes mitosis.
  4. The two cells exchange a micronucleus.
  5. The cells then separate.
  6. The micronuclei in each cell fuse, forming a diploid micronucleus.
  7. Mitosis occurs three times, giving rise to eight micronuclei.
  8. Four of the new micronuclei transform into macronuclei, and the old macronucleus disintegrates.
  9. Binary fission occurs twice, yielding four identical daughter cells.

DNA rearrangements (gene scrambling)

edit

Ciliates contain two types of nuclei:somatic"macronucleus"and thegermline"micronucleus".Only the DNA in the micronucleus is passed on during sexual reproduction (conjugation). On the other hand, only the DNA in the macronucleus is actively expressed and results in the phenotype of the organism. Macronuclear DNA is derived from micronuclear DNA by amazingly extensive DNA rearrangement and amplification.

Development of theOxytrichamacronuclear genome from micronuclear genome

The macronucleus begins as a copy of the micronucleus. The micronuclear chromosomes are fragmented into many smaller pieces and amplified to give many copies. The resulting macronuclear chromosomes often contain only a singlegene.InTetrahymena,the micronucleus has 10 chromosomes (five per haploid genome), while the macronucleus has over 20,000 chromosomes.[27]

In addition, the micronuclear genes are interrupted by numerous "internal eliminated sequences" (IESs). During development of the macronucleus, IESs are deleted and the remaining gene segments, macronuclear destined sequences (MDSs), are spliced together to give the operational gene.Tetrahymenahas about 6,000 IESs and about 15% of micronuclear DNA is eliminated during this process. The process is guided bysmall RNAsandepigeneticchromatinmarks.[27]

Inspirotrichciliates (such asOxytricha), the process is even more complex due to "gene scrambling": the MDSs in the micronucleus are often in different order and orientation from that in the macronuclear gene, and so in addition to deletion, DNAinversionandtranslocationare required for "unscrambling". This process is guided by long RNAs derived from the parental macronucleus. More than 95% of micronuclear DNA is eliminated during spirotrich macronuclear development.[27]

Aging

edit

ln clonal populations ofParamecium,aging occurs over successive generations leading to a gradual loss of vitality, unless the cell line is revitalized by conjugation orautogamy.InParamecium tetraurelia,the clonally aging line loses vitality and expires after about 200 fissions, if the cell line is not rejuvenated by conjugation or self-fertilization. The basis for clonal aging was clarified by thetransplantationexperiments of Aufderheide in 1986[28]who demonstrated that the macronucleus, rather than the cytoplasm, is responsible for clonal aging. Additional experiments by Smith-Sonneborn,[29]Holmes and Holmes,[30]and Gilley and Blackburn[31]demonstrated that, during clonal aging,DNA damageincreases dramatically. Thus, DNA damage appears to be the cause of aging inP. tetraurelia.

Fossil record

edit

Until recently, the oldest ciliate fossils known weretintinnidsfrom theOrdovician period.In 2007, Liet al.published a description of fossil ciliates from theDoushantuo Formation,about 580 million years ago, in theEdiacaran period.These included two types of tintinnids and a possible ancestral suctorian.[32]A fossilVorticellahas been discovered inside a leech cocoon from theTriassic period,about 200 million years ago.[33]

Phylogeny

edit

According to the 2016 phylogenetic analysis,[1]Mesodinieais consistently found as the sister group to all other ciliates. Additionally, two big sub-groups are distinguished inside subphylumIntramacronucleata:SAL (Spirotrichea+Armophorea+Litostomatea) andCONthreePorVentrata(Colpodea+Oligohymenophorea+Nassophorea+Phyllopharyngea+Plagiopylea+Prostomatea).[1]The classProtocruzieais found as the sister group toVentrata/CONthreeP.The classCariacotricheawas excluded from the analysis, but it was originally established as part ofIntramacronucleata[1].
Theodontostomatidswere identified in 2018[34]as its own classOdontostomatea,related toArmophorea.

Ciliophora

Classification

edit
Further information:Wikispecies:Ciliophora
Stentor roeselii

Several different classification schemes have been proposed for the ciliates. The following scheme is based on a molecularphylogenetic analysisof up to four genes from 152 species representing 110 families:[1]

Subphylum Postciliodesmatophora

edit

Subphylum Intramacronucleata

edit
Oxytricha trifallax

Other

edit

Some old classifications includedOpalinidaein the ciliates. The fundamental difference between multiciliateflagellates(e.g.,hemimastigids,Stephanopogon,Multicilia,opalines) and ciliates is the presence of macronuclei in ciliates alone.[35]

Pathogenicity

edit

The only member of the ciliate phylum known to bepathogenicto humans isBalantidium coli,[36]which causes the diseasebalantidiasis.It is not pathogenic to the domestic pig, the primary reservoir of this pathogen.[37]

References

edit
  1. ^abcdeGao, Feng; Warren, Alan; Zhang, Qianqian; Gong, Jun; Miao, Miao; Sun, Ping; Xu, Dapeng; Huang, Jie; Yi, Zhenzhen (2016-04-29)."The All-Data-Based Evolutionary Hypothesis of Ciliated Protists with a Revised Classification of the Phylum Ciliophora (Eukaryota, Alveolata)".Scientific Reports.6:24874.Bibcode:2016NatSR...624874G.doi:10.1038/srep24874.ISSN2045-2322.PMC4850378.PMID27126745.
  2. ^Rotterová, J.; Edgcomb, V. P.; Čepička, I.; Beinart, R. (2022)."Anaerobic ciliates as a model group for studying symbioses in oxygen-depleted environments".The Journal of Eukaryotic Microbiology.69(5): e12912.doi:10.1111/jeu.12912.PMID35325496.S2CID247677842.
  3. ^Foissner, W.; Hawksworth, David, eds. (2009).Protist Diversity and Geographical Distribution.Topics in Biodiversity and Conservation. Vol. 8. Springer Netherlands. p. 111.doi:10.1007/978-90-481-2801-3.ISBN9789048128006.
  4. ^Nielsen, Torkel Gissel; Kiørboe, Thomas (1994)."Regulation of zooplankton biomass and production in a temperate, coastal ecosystem. 2. Ciliates".Limnology and Oceanography.39(3): 508–519.Bibcode:1994LimOc..39..508N.doi:10.4319/lo.1994.39.3.0508.
  5. ^Lynn, Denis (2008).The Ciliated Protozoa 3rd Edition.Springer. pp.129.ISBN978-1-4020-8238-2.
  6. ^"ITIS Report".Integrated Taxonomic Information System.Retrieved11 December2014.
  7. ^Cavalier-Smith, Thomas (2018-01-01)."Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences".Protoplasma.255(1): 297–357.doi:10.1007/s00709-017-1147-3.ISSN1615-6102.PMC5756292.PMID28875267.
  8. ^Yi Z, Song W, Clamp JC, Chen Z, Gao S, Zhang Q (December 2008). "Reconsideration of systematic relationships within the order Euplotida (Protista, Ciliophora) using new sequences of the gene coding for small-subunit rRNA and testing the use of combined data sets to construct phylogenies of the Diophrys-complex".Mol. Phylogenet. Evol.50(3): 599–607.doi:10.1016/j.ympev.2008.12.006.PMID19121402.
  9. ^Miao M, Song W, Chen Z, et al. (2007). "A unique euplotid ciliate, Gastrocirrhus (Protozoa, Ciliophora): assessment of its phylogenetic position inferred from the small subunit rRNA gene sequence".J. Eukaryot. Microbiol.54(4): 371–8.doi:10.1111/j.1550-7408.2007.00271.x.PMID17669163.S2CID25977768.
  10. ^Alfred Kahl (1930).Urtiere oder Protozoa I: Wimpertiere oder Ciliata -- Volume I General Section And Prostomata.
  11. ^"Medical Definition of CILIATA".www.merriam-webster.com.Retrieved2017-12-22.
  12. ^Adl, Sina M.; Bass, David; Lane, Christopher E.; Lukeš, Julius; Schoch, Conrad L.; Smirnov, Alexey; Agatha, Sabine; Berney, Cedric; Brown, Matthew W.; Burki, Fabien; Cárdenas, Paco (2019)."Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes".Journal of Eukaryotic Microbiology.66(1): 4–119.doi:10.1111/jeu.12691.ISSN1550-7408.PMC6492006.PMID30257078.
  13. ^Adl, Sina M.; et al. (2005)."The new higher level classification of eukaryotes with emphasis on the taxonomy of protists".Journal of Eukaryotic Microbiology.52(5): 399–451.doi:10.1111/j.1550-7408.2005.00053.x.PMID16248873.
  14. ^Raikov, I.B. (1969)."The Macronucleus of Ciliates".Research in Protozoology.3:4–115.ISBN9781483186146.
  15. ^abcdArchibald, John M.; Simpson, Alastair G. B.; Slamovits, Claudio H., eds. (2017).Handbook of the Protists(2 ed.). Springer International Publishing. p. 691.ISBN978-3-319-28147-6.
  16. ^Prescott, D M (June 1994)."The DNA of ciliated protozoa".Microbiological Reviews.58(2): 233–267.doi:10.1128/mr.58.2.233-267.1994.ISSN0146-0749.PMC372963.PMID8078435.
  17. ^abcH., Lynn, Denis (2008).The ciliated protozoa: characterization, classification, and guide to the literature.New York: Springer. p. 324.ISBN9781402082382.OCLC272311632.{{cite book}}:CS1 maint: multiple names: authors list (link)
  18. ^Esteban, G. F.; Fenchel, T.; Finlay, B. J. (2010)."Mixotrophy in ciliates".Protist.161(5): 621–641.doi:10.1016/j.protis.2010.08.002.PMID20970377.
  19. ^Altenburger, A.; Blossom, H. E.; Garcia-Cuetos, L.; Jakobsen, H. H.; Carstensen, J.; Lundholm, N.; Hansen, P. J.; Haraguchi, L.; Haraguchi, L. (2020)."Dimorphism in cryptophytes-The case of Teleaulax amphioxeia/Plagioselmis prolonga and its ecological implications".Science Advances.6(37).Bibcode:2020SciA....6.1611A.doi:10.1126/sciadv.abb1611.PMC7486100.PMID32917704.
  20. ^DeLong, John P.; Van Etten, James L.; Al-Ameeli, Zeina; Agarkova, Irina V.; Dunigan, David D. (2023-01-03)."The consumption of viruses returns energy to food chains".Proceedings of the National Academy of Sciences.120(1): e2215000120.Bibcode:2023PNAS..12015000D.doi:10.1073/pnas.2215000120.PMC9910503.PMID36574690.
  21. ^abLynn, Denis (2008).The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature(3 ed.). Springer. pp.58.ISBN978-1-4020-8238-2.1007/978-1-4020-8239-9
  22. ^abcH., Lynn, Denis (2008).The ciliated protozoa: characterization, classification, and guide to the literature.New York: Springer. p. 23.ISBN9781402082382.OCLC272311632.{{cite book}}:CS1 maint: multiple names: authors list (link)
  23. ^Berger JD (October 1986). "Autogamy in Paramecium. Cell cycle stage-specific commitment to meiosis".Exp. Cell Res.166(2): 475–85.doi:10.1016/0014-4827(86)90492-1.PMID3743667.
  24. ^abcRaikov, I.B (1972)."Nuclear phenomena during conjugation and autogamy in ciliates".Research in Protozoology.4:149.
  25. ^Finley, Harold E. "The conjugation ofVorticella microstoma."Transactions of the American Microscopical Society (1943): 97-121.
  26. ^"Introduction to the Ciliata".Retrieved2009-01-16.
  27. ^abcMochizuki, Kazufumi (2010)."DNA rearrangements directed by non-coding RNAs in ciliates".Wiley Interdisciplinary Reviews: RNA.1(3): 376–387.doi:10.1002/wrna.34.PMC3746294.PMID21956937.
  28. ^Aufderheide, Karl J. (1986). "Clonal aging inParamecium tetraurelia.II. Evidence of functional changes in the macronucleus with age ".Mechanisms of Ageing and Development.37(3): 265–279.doi:10.1016/0047-6374(86)90044-8.PMID3553762.S2CID28320562.
  29. ^Smith-Sonneborn, J. (1979). "DNA repair and longevity assurance in Paramecium tetraurelia".Science.203(4385): 1115–1117.Bibcode:1979Sci...203.1115S.doi:10.1126/science.424739.PMID424739.
  30. ^Holmes, George E.; Holmes, Norreen R. (July 1986). "Accumulation of DNA damages in agingParamecium tetraurelia".Molecular and General Genetics.204(1): 108–114.doi:10.1007/bf00330196.PMID3091993.S2CID11992591.
  31. ^Gilley, David; Blackburn, Elizabeth H. (1994)."Lack of telomere shortening during senescence inParamecium"(PDF).Proceedings of the National Academy of Sciences of the United States of America.91(5): 1955–1958.Bibcode:1994PNAS...91.1955G.doi:10.1073/pnas.91.5.1955.PMC43283.PMID8127914.
  32. ^ Li, C.-W.; et al. (2007). "Ciliated protozoans from the Precambrian Doushantuo Formation, Wengan, South China".Geological Society, London, Special Publications.286(1): 151–156.Bibcode:2007GSLSP.286..151L.doi:10.1144/SP286.11.S2CID129584945.
  33. ^Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Øjvind; Taylor, Edith L. (2012-12-18)."Triassic leech cocoon from Antarctica contains fossil bell animal".Proceedings of the National Academy of Sciences of the United States of America.109(51): 20971–20974.Bibcode:2012PNAS..10920971B.doi:10.1073/pnas.1218879109.ISSN1091-6490.PMC3529092.PMID23213234.
  34. ^abFernandes, Noemi M.; Vizzoni, Vinicius F.; Borges, Bárbara do N.; Soares, Carlos A.G.; da Silva-Neto, Inácio D.; Paiva, Thiago da S. (2018),"Molecular phylogeny and comparative morphology indicate that odontostomatids (Alveolata, Ciliophora) form a distinct class-level taxon related to Armophorea",Molecular Phylogenetics and Evolution,126:382–389,doi:10.1016/j.ympev.2018.04.026,ISSN1055-7903,PMID29679715,S2CID5032558
  35. ^Cavalier-Smith, T. (2000). Flagellate megaevolution: the basis for eukaryote diversification. In: Leadbeater, B.S.C., Green, J.C. (eds.).The Flagellates. Unity, diversity and evolution.London: Taylor and Francis, pp. 361-390, p. 362,[1].
  36. ^"Balantidiasis".DPDx — Laboratory Identification of Parasitic Diseases of Public Health Concern.Centers for Disease Control and Prevention. 2013.
  37. ^Schister, Frederick L. and Lynn Ramirez-Avila (October 2008)."Current World Status ofBalantidium coli".Clinical Microbiology Reviews.21(4): 626–638.doi:10.1128/CMR.00021-08.PMC2570149.PMID18854484.

Further reading

edit
  • Lynn, Denis H. (2008).The ciliated protozoa: characterization, classification, and guide to the literature.New York: Springer.ISBN9781402082382.OCLC272311632.
  • Hausmann, Klaus; Bradbury, Phyllis C., eds. (1996).Ciliates: cells as organisms.Stuttgart: Gustav Fischer Verlag.ISBN978-3437250361.OCLC34782787.
  • Lee, John J.; Leedale, Gordon F.; Bradbury, Phyllis C., eds. (2000).An illustrated guide to the protozoa: organisms traditionally referred to as protozoa, or newly discovered groups(2nd ed.). Lawrence, KS: Society of Protozoologists.ISBN9781891276224.OCLC49191284.
edit
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ciliate&oldid=1253111341"