US EPA

3307772 

Journal Article 

Histochemical and X-ray studies on tissue concretions and shells of Margaritifera margaritifera (Linnaeus) 

Pekkarinen, M; Valovirta, I 

1997 

1 

Journal of Shellfish Research
ISSN: 0730-8000
EISSN: 1943-6319 

16 

1 

169-177 

English 

WOS:A1997XM07200027 

http://://WOS:A1997XM07200027
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Concretions of two types, calcified (calcium and phosphorus containing) and lipofuscin containing, were found to occur in the tissues of the freshwater pearl mussel, Margaritifera margaritifera (L.), in Finland. Both concretions can also contain Fe3+, and the calcified concretions can contain manganese and sometimes Fe2+. The calcified concretions comprise (1) small spherules in the mantle and simple or combined spherules above the gill axes and the pericardial glands, in the gills. and among the heart muscle cells, (2) supporting rods in the gills, and (3) very small granules between the Leydig cells and body muscles. The mussel effectively concentrates calcium even from very soft water and stores it mainly in the mantle as extensive masses of small spherules. Large concretions (10-15 mu m) in the pericardial gland cells of the pearl mussel may be an effective means for the concentration and excretion of lipofuscin and iron. Similar but smaller concretions can be found also elsewhere in the mussel, especially in the kidney. In the glochidial shells of the Anodonta species, calcium is mostly in the form of carbonate. Because the glochidial shells of M. margaritifera are thin and poorly calcified, some phosphorus and sulfur in the X-ray spectra may come from the larval mantle or the organic matter of the shell. Iron and manganese from mussel concretions do not markedly enter glochidial or adult shells. The precipitate on the adult M. margaritifera shell, however, contains large amounts of these elements. 

freshwater pearl mussel; Margaritifera margaritifera; Anodonta; calcium; iron; metal; concretion; lipofuscin; glochidium; shell