On the Enigmatic Hook of the Metaradiophryids (Alveolata, Ciliophora)

Klaus Hausmann,

Gerd Günther,

Diana Lehmann,

Renate Radek

The astomatous metaradiophryids are ciliates which live endosymbiotically in earthworms (Annelida, Lumbricidae). Their prominent hook apparatus is demonstrated in detail in light micrographs of living organisms as well as in scanning electron micrographs of Parducz-fixed cells. Since it was first observed, this structure has been interpreted as a ‘holdfast’ organelle preventing ciliates from being expelled prematurely from the intestine of the worm along with its excrements. No active movement of the hook has been reported in earlier papers or in our recent studies. Nevertheless, a detailed description of different parts of the hook apparatus exists in older literature, including a hypothesis on how these elements interact with each other to function as a holdfast device – without any experimental evidence. The suspected mode of function of this structure is questioned and critically discussed.
Słowa kluczowe: Astomatous ciliates, Metaradiophrya spec., hook structure, holdfast organelle

Beers C. D. (1938) Structure and division in the astomatous ciliate Metaradiophrya asymmetrica. n. sp. J. Elisha Mitchell Sci. Soc. 54: 111–125

Dixon R. F. (1975) The astomatous ciliates of British earthworms. J. Biol. Educ. 9: 29–39

Doflein F., Reichenow E. (1953) Lehrbuch der Protozoenkunde, 6. Auflage. Gustav Fischer Verlag, Jena

Günther G. (2013) Ciliaten im Darm von Oligochaeten – Endokommensalen von Eisenia foetidaMikrokosmos 102: 339–344

Hayat M. A. (2000) Principles and techniques of electron microscopy – Biological applications, 4th edition. Cambridge University Press, Cambridge

Heidenreich E. (1935) Untersuchungen an parasitischen Ciliaten aus Anneliden. Teil I: Systematik. Arch. Protistenkd. 84: 315–392

Parducz B. (1967) Ciliary movement and coordination in ciliates. Int. Rev. Cytol. 21: 91–128

Puytorac P. de (1954) Contribution à l’étude cytologique et taxonomique des Infusoires astomes. Ann. Sci. Nat. Zool. 16: 85–270

Stein F. (1854) Die Infusionsthiere auf ihre Entwickelungsgeschichte untersucht. Engelmann, Leipzig

Williams G. W. (1942) Observations on several species of Metaradiophrya (Protozoa, Ciliata). J. Morph. 70: 545–589

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