The cell structure of the reticulopodial amoeba Filoreta marina Bass et Cavalier-Smith (Cercozoa)


The cell structure of a reticulopodial amoeba, Filoreta marina Bass et Cavalier-Smith, is described. The cell is covered by a unitary membrane; glycostyles are absent. The life cycle comprises the uninucleate stage, multinucleate plasmodium, and spherical uninucleate cysts. The microtubules inside pseudopodia and the flagella are absent. The vesicular nuclei, endoplasmic reticulum, and Golgi apparatus are of a typical structure. The plasmodium produces a branched network of narrow anastomosing (reticulopodia) and wide pseudopodia. Thin unbranched micropseudopodia have also been observed. Oval mitochondria with a size of 0.3 × 0.6 μm contain the tubular cristae. A bidirectional motion of the cytoplasm inside the reticulopodia has been detected. Extrusomes (extrusive organelles) have not been found. The contractile vacuole is absent. F. marina feeds on bacteria. A similarity of this amoeba to other filose and reticulopodial amoebas is discussed.

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  1. 1.

    Bass, D., Chao, E.E.-Y., Nikolaev, S., et al., Phylogeny of Novel Naked Filose and Reticulose Cercozoa: Granofilosea cl. n. and Proteomyxidea Revised, Protist, 2009, vol. 160, pp. 75–109.

    PubMed  Article  Google Scholar 

  2. 2.

    Benwitz, G. and Grell, K.G., Ultrastruktur Mariner Amöben. III. Stereomyxa Angulosa, Arch. Protistenk., 1971, vol. 113, pp. 68–79.

    Google Scholar 

  3. 3.

    Cavalier-Smith, T. and Chao, E.E.-Y., Phylogeny and Classification of Phylum Cercozoa (Protozoa), Protist, 2003, vol. 154, pp. 341–358.

    PubMed  Article  Google Scholar 

  4. 4.

    Grant, J., Tekle, Y.I., Anderson, O.R., et al., Multigene Evidence for the Placement of a Heterotrophic Amoeboid Lineage Leukarachnion sp. among Photosynthetic Stramenopiles, Protist, 2009, vol. 160, pp. 376–385.

    PubMed  Article  Google Scholar 

  5. 5.

    Grell, K.G., The Life-Cycle of the Marine Protist Reticulosphaera socialis Grell, Arch. Protistenk., 1989, vol. 137, pp. 177–197.

    Article  Google Scholar 

  6. 6.

    Grell, K.G., Corallomyxa nipponica n. sp. and the Phylogeny of Plasmodial Protists, Arch. Protistenk., 1991, vol. 140, pp. 303–320.

    Article  Google Scholar 

  7. 7.

    Grell, K.G., Leucodictyon marinum n. gen., n. sp., a Plasmodial Protist with Zoospore Formation from the Japanese Coast, Arch. Protistenk., 1991, vol. 140, pp. 1–21.

    Article  Google Scholar 

  8. 8.

    Grell, K.G., Reticulamoeba gemmipara n. gen., n. sp., an “Amoebo-Flagellate” with Reticulopodia and Zoosporogenesis, Arch. Protistenk., 1994, vol. 44, pp. 55–61.

    Article  Google Scholar 

  9. 9.

    Marszalek, D.S., Observations on Iridia diaphana, a Marine Foraminifer, J. Protozoolog., 1969, vol. 16, pp. 599–611.

    Google Scholar 

  10. 10.

    Mikrjukov, K.A. and Mylnikov, A.P., A Study of the Structure and the Life Cycle of Gymnophrys cometa Cienkowski, 1876 (Gymnophrea cl. n.) with Remarks on the Taxonomy of the Amoebo-Flagellated Genera Gymnophrys and Borkovia, Acta Protozool., 1998, vol. 37, pp. 179–189.

    Google Scholar 

  11. 11.

    Patterson, D.J., Simpson, A.G.B., and Rogerson, A., Amoebae of Uncertain Affinities, in An Illustrated Guide to the Protozoa, Lawrence: Soc. Protozool., 2000, pp. 804–827.

    Google Scholar 

  12. 12.

    Porter, D., Ultrastructure of Labyrinthula, Protoplasma, 1969, vol. 67, pp. 1–19.

    Article  Google Scholar 

  13. 13.

    Pussard, M. and Pons, R., Étude des Generes Leptomyxa et Gephyramoeba (Protozoa, Sarcodina). II — Leptomyxa flagellata Goodey, 1915, Protistologica, 1976, vol. 12, pp. 307–319.

    Google Scholar 

  14. 14.

    Tekle, Y.I., Grant, J., Cole, J.C., et al., A Multigene Analysis of Corallomyxa tenera sp. nov. Suggests Its Membership in a Clade That Includes Gromia, Haplosporidia and Foraminifera, Protist, 2007, vol. 158, pp. 457–472.

    PubMed  Article  CAS  Google Scholar 

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Correspondence to A. P. Myl’nikov.

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Original Russian Text © A.P. Myl’nikov, A.A. Myl’nikov, 2011, published in Biologiya Vnutrennikh Vod, No. 4, 2011, pp. 41–47.

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Myl’nikov, A.P., Myl’nikov, A.A. The cell structure of the reticulopodial amoeba Filoreta marina Bass et Cavalier-Smith (Cercozoa). Inland Water Biol 4, 440–445 (2011).

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  • Filoreta marina
  • ultrastructure
  • reticulopodia
  • multinucleate plasmodia
  • Cercozoa