Cytometric observations on hemopoietic kidney tissue in catfish (Ictalurus melas).

: Peroxidase-positive and negative lymphoid hemoblasts present in Catfish kidney were measured, in order to verify whether large lymphoid hemoblasts give rise to the granulocytic leukocytes and small lymphoid hemoblasts give rise to the erythrocytes, thrombocytes and lymphocytes. The cytometric study indicates that granulocytic cells arise prevalently by large and intermediate sized hemoblasts, but also by small hemoblasts. The other cells arise prevalently by small and intermediated sized hemoblasts and by large ones as well. Two different types of hemoblasts were distinguished but not on the basis of their size.