Aluminium deposition in hydras.

The aim of this research was to explore, compare and explain the appearance, purpose and possible distribution of aluminium depositions in symbiotic and aposymbiotic hydra species. Al deposition in treated hydras appeared pink as single and multiple aluminium depositions or as clusters in the shape of globular or spot-like structures inside the cytoplasm of the hydra cells. Areas ofaluminium deposits were also present. Endosymbiotic algae in the green hydra were occasionally coloured pink. Authors suggest that the mesoglea represented a buffer of some sort as the depositions were almost completely absent in some parts of the body such as the gastroderm of brown hydras or the ectoderm in some concentrations of green hydras, or the mesoglea may have the ability to dispose of all the present aluminium and the occurrence and distribution ofthese depositions may be a mechanism of cellular detoxification and might be species specific.