In biomedical research always it is a challenge to find an experimental model to test various innovative drugs. In modern-day hematology, research zebrafish demonstrated its suitability and complex nature of known physiological functions of zebrafish has some resemblance to humans that makes these tiny fish in the forefront of cutting edge modern research. The blood of zebrafish is curious if we look at the RBC. In human RBC in peripheral blood is non-nucleated cells, but in these tiny fish blood has nucleated RBCs. Zebrafish are commonly used as a vertebrate model to study multiple human diseases including cardiovascular disease. Zebrafish model is suitable for drug discovery research because its genome is homologous to the human genome by 70%. Besides, zebrafish develop rapidly during a short period where reaches to adulthood phase. In research zebrafish embryos and adult zebrafish are widely used to study metabolic and neurological functions.