The elemental composition of the chloragosomes of two earthworm species (Lumbricus terrestris and Allolobophora longa) determined by electron probe X-ray microanalysis of freeze-dried cryosections.

The elemental composition of the chloragosomes of the two earth-worm species, one with complex highly active Ca-secreting calciferous glands (L. terrestris) and the other with non-secretory glands (A. longa), was determined by the electron probe X-ray microanalysis of unfixed freeze-dried cryosections. The predominant constituents of the chloragosomes of both species were P, Ca, Zn and S, with lesser quantities of K, Cl and Fe. The most striking species differences in chloragosomal chemistry were the higher concentrations (expressed as relative mass fractions) of P(x 2.1), Ca(x 1.5), and Zn(x 2.3) in L. terrestris, and the much higher S(x 19.6) in A. longa. These differences were discussed in relation to the general ecophysiology of the two species, and more specifically in relation to heavy metal uptake and binding.