Content and Ultrastructural Localization of Transitional Metals in Ascidian Ovary

The content of some transitional metals (Ti, V, Cr. Mn. Fe, Cu) in the ovary of Ascidia malaca and Ciona intestinalis and in the gonads ofPolycarpa gracilis has been reported. The metals were localized histospectrographically and ultrastructurally. In the ovaries of C. intestinalis. the quantitative analysis shows a variable content of metals related to the ovary maturative cycle. The iron is localized in the electron dense cytoplasmic granules ofA. malaca oocytcs and in the cytoplasmic dense formation of P. gracilis test cells. Cl, S, Si and P are present in the test, follicles and inierovarian cells of all examined species. The results are discussed in relation to the zoological position of these species. The presence of metals and Ascidiacee phylogenesis might be correlated.