choanocyte

(noun)

any of the cells in sponges that contain a flagellum and are used to control the movement of water

Related Terms

Examples of choanocyte in the following topics:

  • Morphology of Sponges

    • Whereas pinacocytes line the outside of the sponge, choanocytes tend to line certain inner portions of the sponge body that surround the mesohyl.
    • The structure of a choanocyte is critical to its function, which is to generate a water current through the sponge and to trap and ingest food particles by phagocytosis.
    • Note that there is a similarity in appearance between the sponge choanocyte and choanoflagellates (Protista).
    • The cumulative effect of the flagella from all choanocytes aids the movement of water through the sponge: drawing water into the sponge through the numerous ostia, into the spaces lined by choanocytes, and eventually out through the osculum (or osculi).
    • Amoebocytes have a variety of functions: delivering nutrients from choanocytes to other cells within the sponge; giving rise to eggs for sexual reproduction (which remain in the mesohyl); delivering phagocytized sperm from choanocytes to eggs; and differentiating into more-specific cell types.

  • Pre-Cambrian Animal Life

    • Some protist species called choanoflagellates closely resemble the choanocyte cells in the simplest animals, sponges.

  • Physiological Processes in Sponges

    • Bacteria smaller than 0.5 microns in size are trapped by choanocytes, which are the principal cells engaged in nutrition, and are ingested by phagocytosis.
    • Oocytes arise by the differentiation of amoebocytes and are retained within the spongocoel, whereas spermatozoa result from the differentiation of choanocytes and are ejected via the osculum.

  • Contractile Vacuoles in Microorganisms

    • Through the process of evolution, the CV was mostly eliminated in multicellular organisms; however it still exists in the unicellular stage of several multicellular fungi and in several types of cells in sponges, including amoebocytes, pinacocytes, and choanocytes.

  • Constructing an Animal Phylogenetic Tree

    • These protist cells strongly resemble sponge choanocyte cells.