cassiosome

Etymology
From, referring to a genus containing some of the jellyfish found to produce them. Coined 2020 by Cheryl L. Ames, et al., in a paper published in Communications Biology (see quotations below).

Noun

 * 1) A stinging-cell structure, composed of a layer of mainly nematocytes surrounding a core of dinoflagellates, amoebocytes and mesoglea, expelled within mucus by  jellyfish to sting (and in some cases kill) prey in the surrounding water.

Usage notes

 * Water containing clouds of cassiosomes is referred to as.