**5. Conclusions**

The presented algorithm does not require the use of contrast agents and may be used to visualize cardiac morphology and measure dynamics in zebrafish embryos without anesthesia. We believe that it may help to shed light on the mechanisms by which the cardiovascular system's activity is initiated under natural conditions. Continuous study of the heart function and vessel structure transformation using the proposed algorithm may contribute to recognizing possible warning signs of developmental disorders at the very early stages and understanding the symptoms of various diseases, i.e., help to improve the techniques for their correct diagnosis and timely treatment.

Further development of this technique may include the interactive analysis of vessel structure and function in both normal and pathological condition at embryonic stages, as well as detecting and studying the changes in zebrafish cardiovascular system initiation, development and functioning induced by various environmental stressors.
