A Comparative Study on the Size and Shape of Human and Fish Erythrocytes Using Laser Diffraction Technique

Abstract- Erythrocyte morphology is a significant indicator of physiological status, oxygentransport efficiency, and species-specific variations. In the present study, laser diffraction, ahumble, fast, and non-invasive optical technique, was employed to compare the morphology oferythrocytes in human blood and two freshwater teleost fishes, Labeo rohita and Channa striata.Blood smear samples were illuminated using a helium–neon (He–Ne) laser, and erythrocytedimensions were predictable from the corresponding Fraunhofer diffraction patterns. The studyshown significant variances in erythrocyte morphology between human and fish samples, as well asbetween the two fish species. Human erythrocytes were smaller, circular, and anucleated, whereasfish erythrocytes were larger, elliptical, and nucleated. The measured morphometric variationswere consistent with known species-specific hematological characteristics. These conclusionsdemonstrate that laser diffraction provides a rapid, reliable, cost-effective, and non-destructiveapproach for comparative erythrocyte morphometry. The technique shows significant potential forapplications in fish hematology, comparative physiology, veterinary diagnostics, and biomedicalresearch.