Haematological parameters have been recognized as valuable tools for monitoring fish health. Haematological and serum biochemical parameters were studied and compared different feeding behaviour of teleost fishes. Three marine teleost fishes, Lates calcarifer (carnivores), Mugil cephalus (omnivores) and Chanos chanos (herbivores), were carried out in order to find out a normal range of blood parameters which would serve as baseline data for assessment of the health status of the fish as well as reference point for future comparative surveys. Blood parameters such as red blood cell count (RBC) and white blood cells count (WBC), haemoglobin, haematocrit, mean cell haemoglobin concentration (MCHC), mean cell volume (MCV), mean cell haemoglobin, glucose, protein, cholesterol and urea were estimated from teleost fishes of different trophic level. Statistical analysis revealed that differences in haematological parameters between marine fish were significant (P < 0.01). The result revealed that haematological RBC/WBC ratio, MCV and MCHC were significantly correlated at P < 0.05 level. The RBC/WBC level increased due to the decrease in WBC during the study. Blood serum biochemical parameters can be used for confirming the maturity and monitoring any changes in the quality of waters and related soils.