cnidosac
Cnidosac refers to a specialized organ found in certain opisthobranch molluscs, most notably aeolid nudibranchs, that houses nematocysts (the stinging capsules) stolen from cnidarian prey. The term describes a sac-like structure at the end of each ceras, the finger-like projections on the nudibranch’s back, which is connected to the digestive tract by a short duct.
In aeolid nudibranchs, the animal sequesters nematocysts from consumed cnidarians, such as hydroids or soft corals,
The presence of cnidosacs represents a form of defense-based trophic specialization: the animal repurposes cnidarian defenses
Cnidosacs have been observed in diverse marine environments, from temperate to tropical waters, where aeolid nudibranchs