Differentiation of eosinophilic granulocytes of carp (Cyprinus carpio L.)

Electron-microscopic studies were conducted to observe ultrastructural changes during differentiation of eosinophilic granulocytes in carp (Cyprinus carpio L.). Differentiation at the myelocyte stage was found to relate to specific granules made of dense and light fields. By maturation they assume a mosaic-like texture and in each granule of mature granulocytes, a light, central "internum" and a peripheral dense wrapper can be distinguished. The activity peroxidase and acid phosphatase is located in the internum and of peroxidase in the wrapper of the granules.