nematocyst

plural nematocysts

1. biologyA capsule, in certain cnidarians, containing a barbed, threadlike tube that delivers a paralyzing sting

   Nematocyst discharge is another example of the Rubicon principle – it either fires or it does not.

   2014, Anthony K. Campbell, Intracellular Calcium, page 350

   2 more examples

   Often one sees, on surface view, a distinctly rounded vacuole, occupying a position in the cell occupied in others by a large nematocyst.

   1885, R. J. Harvey Gibson, “Observations on the nematocysts of Hydra fusca”, in Proceedings of the Literary and Philosophical Society of Liverpool, volume 39, page 30

   The young nematocyst decreases in size and becomes coarsely granular, the granules arranging themselves in a spiral line close under the external membrane.

   1902, Arthur Willey, Zoological Results Based on Material from New Britain, New Guinea, Loyalty Islands and Elsewhere, page 379

   Synonyms: cnida, cnidocyst, cnidocyte