nematocyst

noun

nem·​a·​to·​cyst ˈne-mə-tə-ˌsist 

ni-ˈma-tə-

: one of the stinging capsular organelles of the tentacle of a cnidarian (such as a box jellyfish or sea anemone) that contains a coiled, hollow, usually barbed, venomous thread which is discharged especially for catching prey and defending against enemies

Each nematocyst contains a spiral-coiled thread tipped with a toxin-bearing barb that can be ejected into the skin.

—Peter F. Weller

called also cnidocyst

Examples of nematocyst in a Sentence

Recent Examples on the Web

Jellyfish tentacles have thousands of nematocysts that can pierce the skin and inject venom. —Nick Blackmer, Verywell Health, 29 June 2023

The mostly transparent jellyfish typically have a reddish-orange or yellow cross in the center of their bodies, as well as 60 to 80 short and long tentacles with nematocysts or stinging cells, the department said. —Saleen Martin, USA TODAY, 8 June 2023

Its tentacles contain stinging nematocysts that can deliver venom capable of paralyzing and killing small fish and crustaceans. —Leada Gore | [e-mail], al, 15 Mar. 2023

But the authors point out that these nematocysts can only be fired once, like a harpoon, remaining in the target. —Jennifer Ouellette, Ars Technica, 7 Mar. 2023

In each is a structure called a nematocyst which contains the venom and a harpoon-like structure on a biological thread. —Christie Wilcox, Discover Magazine, 2 June 2015

When the nematocyst fires, the shaft is ejected first and turns right-side out. —Viviane Callier, Scientific American, 18 Aug. 2022

Now a team led by Matt Gibson and Ahmet Karabulut of the Stowers Institute for Medical Research in Kansas City, Mo., has used cutting-edge imaging technology to study nematocyst firing in very fine detail. —Viviane Callier, Scientific American, 18 Aug. 2022

Using super-resolution fluorescence and electron microscopes, the researchers observed a detailed sequence of events involving a stiff shaft and a flexible, whiplike filament that starts out coiled around it within the nematocyst. —Viviane Callier, Scientific American, 18 Aug. 2022

Word History

Etymology

International Scientific Vocabulary

First Known Use

1862, in the meaning defined above

Kids Definition

nematocyst

noun

nem·​a·​to·​cyst ˈnem-ət-ə-ˌsist 

ni-ˈmat-ə-

: one of the tiny stinging organs of various coelenterates (as jellyfishes and corals) used in catching prey

Medical Definition

nematocyst

noun

nem·​a·​to·​cyst ˈnem-ət-ə-ˌsist  ni-ˈmat-ə- 

: one of the minute stinging organelles of various coelenterates

called also stinging cell