Ultrastructure of granulocytes of teleost fish (Salmoniformes, Cypriniformes, Perciformes)

Analysis of data on ultrastructure of granulocytes of freshwater and marine bony fish of orders Salmoniformes, Cypriniformes, and Perciformes showed that in all studied species there were revealed two types of granulocytes-neutrophils and eosinophils. The exception was the bluefish Pomatomus saltatrix L. whose pronephros hemopoietic tissue was found to contain one type of the granulocyte line-neutrophils. The identification parameters of granular leukocytes are specific granules filling the cytoplasm. The main form of specific granules in neutrophils of bony fish of various phylogenetic groups is an elongated granule with different distribution of fibrils or a granule that has fibrils-formed crystalloid. Eosinophil granules are mainly of large, electron-dense, homogenous form.