Detection of high concentration of magnesium and calcium in the nematocysts of various cnidarians
Weber, J.; Klug, M.; Tardent, P.
Experientia 43(9): 1022-1025
ISSN/ISBN: 0014-4754 Accession: 005117223
An X-ray spectral analysis (EDAX) of isolated undischarged nematocysts of various cnidarians Hydrozoa, Scyphozoa, Anthozoa) revealed the presence of extremely high concentrations of divalent cations. In Hydra nematocysts both Ca2+ (conc. 0.36 .mu.mole/mg dry cysts) and Mg2+ (conc. 0.80 .mu.mole/mg dry cysts) ions add up to a total in situ concentration of 0.5 to 1.0 M. More than 85% of the cations, which are believed to be involved in cyst discharge, are contained in the soluble fraction of the cysts, where they must be bound to high molecular weight molecules.