VPP 322: Aquatic Animal Diseases, Health Care and Management (1+1)

ERYTHROCYTES

• Erythrocytes are nucleated blood cells which carry the red-pigmented protein hemoglobin. Their primary function is in the transport of gases throughout the body. Haemoglobin is a red-pigmented protein occurring in the blood cells of vertebrates. Haemoglobin combines readily with oxygen to form oxyhaemoglobin responsible for transferring oxygen through the blood system. Hemoglobin is made up of the colourless protein globin, and the red-yellow pigment haeme which contains iron. Oxygen is transported in combination with the ferrous iron of the haeme.

Structure and function

• Fish erythrocytes are elongated, elliptical cells with an oval, centrally-located, nucleus. Immature erythrocytes are called polychromatocytes .
• Erythrocytes function in the transport of oxygen and, to a much lesser degree, carbon dioxide. Haemoglobin is a large protein which (except in the primitive jawless fishes) consists of four smaller protein subunits, two alpha chains and two beta chains, each of which carries one molecule of oxygen. These peptides are bound together by four haeme rings, and an iron atom is bound in the centre of each haeme ring. 

Erythrocyte of fish

Source: Scielo.br