PHAGOTROPHY IN GYMNODINIUM FUNGIFORME (PYRRHOPHYTA): THE PEDUNCLE AS AN ORGANELLE OF INGESTION1

Authors

  • Howard J. Spero

    1. Department of Oceanography, Texas A&M University, College Station, Texas 77843
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    • 2

      Department of Biological Sciences, University of California, Santa Barbara, California 93106.


  • 1

    Accepted: 2 March 1982.

  • This research constitutes a portion of a thesis to the Graduate College, Texas A&M University in partial fulfillment of the requirement for the Master of Science. I acknowledge the helpful suggestions made by the members of my committee, Drs. T. J. Bright, E. R. Cox, R. M. Darnell and J. Neff. I also thank Dr. G. A. Fryxell for the use of her laboratory and equipment, and Drs. M. Elbrächter, K. Steidinger, B. M. Sweeney and F. J. R. Taylor for their thought-provoking discussions and critical review of this manuscript. Funds were provided by the Oceanography Department, Texas A&M University and Texas A&M mini-grant Project No. 15707.

ABSTRACT

The non-photosynthetic phagotrophic dinoflagellate, Gymnodinium fungiforme Anissimova, ingests prey cytoplasm through a highly extensible structure called the peduncle. Although the peduncle is not observable when G. fungiforme is swimming, it protrudes 8–12 μm from the sulcal-angular vicinity of the cell during feeding, and is approximately 3.3 μm wide when the cytoplasm of its prey is flowing through it. A circular-oval ring of overlapping microtubules, the ‘microtubular basket’ may be seen in transmission electron microscope sections of G. fungiforme and it is inferred that this structure is a cross section of a retracted peduncle. The microtubular basket-peduncle complex is discussed in relation to similar structures in other dinoflagellates and to the tentacle of the suctorian ciliates which have a homologous ingestion system.

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