Unit 1 - Fish Blood Constituents
Erythrocytes - Origins

Back to Erythrocytes

 

Erythrocytes are formed from embryonic cells in the peripheral blood, called erythroblasts. These erythroblasts undergo successive mitoses, and develop increasing amounts of haemoglobin, finally giving rise to fully differentiated erythrocytes. 

In the more advanced bony fishes, Osteichthyes,  the kidney is where erythropoieses takes place, while in the more primitive jawless fishes, Agnatha, and cartilaginous fishes, Chondrichthyes, the blood is a major site of erythrocyte synthesis.

Notes

Osteichthyes graphic:

KIDNEY: Organ of excretion and water regulation in vertebrates, consisting of numerous nephrons and their blood supply.   The kidney also functions in formation of blood cells in some animals including the bony fishes.

ERYTHROPOEISIS: The term erythropoeisis refers to the formation of red blood cells, or erythrocytes.

Agnatha graphic :

Chondrichthyes graphic: