Comparative haematology of ten species of marine fish from Visakhapatnam Coast

A comparative study has been made of haematological parameters (erythrocyte numbers, leucocyte numbers, haematocrit and haemoglobin), erythrocyte indices (MCV, MCH and MCHC) and cytometric measurements (cell and nucleus) of 10 species of marine fish from the Visakhapatnam Coast, of which six are from harbour waters, three from rock pools and one from inshore waters. It is found that active fish have high values of erythrocyte numbers, haematocrit, haemoglobin and nucleo/cytoplasmic ratio and low values of leucocyte numbers and erythrocyte cytosome measurements. The most active of all is the inshore species Rastrelliger kanagurta depicting the haematological requirements of an active fish with high oxygen demand to meet the requirements of high metabolic rate. The other active fish such as Megalops cyprinoides and Mugil cephalus are intermediate, with the rock pool fish and Caranx carangus with low values of nucleo/cytoplasmic ratio at the other extreme.