Abstract：The smear and print of head kidney, body kidney, and spleen of grouper hybrid Epinephelus lanceolatus ♂ × E. fuscoguttatus ♀ were stained with Wright′s dye solution, and the blood cells were observed, photographed, measured, and statistically processed to probe into the development of haemocytes. The results showed that the development of red blood cells was divided into four stages: namely proerythroblast, immature erythroblast, erythrocyte and old erythrocyte, in which the cell volume was getting smaller during the maturation of the erythroid cells. The granuloid lineages were divided into five stages: progranulocytes, promyelocytes, mesenchymal granulocytes, late granulocytes and mature granulocytes, in which the cell volume was getting smaller, however, from the neutrophilic metagranulocyte to the neutrophilic granulocyte, the their sizes were larger than the cells of other fish from the progranuloblast to the neutrophilic metagranulocyte. During the maturation of the eosinophilic granulocytes, they were reduced in size. The monocytoid lineage and lymphoid lineage were divided into three stages: primitive stages, immature stage and mature stage, and these two kinds of cells had regularly reduced in size during development. There were larger cells in the grouper hybrid than those in other fishes, much larger neutrophilic granulocyte than eosinophilic granulocyte, without proerythroblast and progranuloblast in spleen. Only macrophage and reticulocyte were oberved in body kidney. The developments of erythrocyte, granulocyte, lymphocyte, and monocyte were found mainly in head kidney, and then in body kidney. Erythrocytes, and granulocytes developed mainly in head kidney and body kidney. The findings indicated that head kidney, body kidney, and spleen were the main sites of genesises of primary monocytes and protolymphocytes.
2021, Vol. 40 
