Jellyfish nematocyst discharge

Jellyfish nematocyst discharge is a rapid, high-pressure biological process involving the explosive ejection of a venom-filled tubule from a specialized organelle called a nematocyst. This event is among the fastest mechanical processes in nature, occurring in as little as 700 nanoseconds and achieving accelerations of over 5 million g, driven by internal osmotic pressures of up to 15 MPa generated by poly-gamma-glutamate [4, 15, 18]. The process is triggered by a combination of mechanical touch and chemical cues (such as prey-derived amino acids or sugars) that act on cnidocyte receptors to open specialized voltage-gated calcium channels ($nCa_V$), allowing a critical influx of calcium ions that initiates discharge [3, 4]. In a clinical context, nematocyst discharge is the primary mechanism of cnidarian envenomation, leading to severe pain, tissue necrosis, and in some species, systemic toxicity or cardiac arrest [16, 17]. While the discharge itself is a physiological process rather than a single molecule, it is a significant target for topical preventative agents. Compounds such as lidocaine, lanthanum, and certain cosmetic ingredients like hydroxyacetophenone have been shown to inhibit discharge by modulating ion channel activity or stabilizing the cnidocyte membrane [1, 10, 12]. Understanding the molecular filters, particularly the $nCa_V$ channel, is essential for developing effective first-aid protocols and sting-prevention technologies [4, 11].

Other names

Cnidocyte dischargeNematocyte firingCnidae dischargeCnidocyst eversionJellyfish stinging response