Proteins being mirror to molecular signature of an organism, their potential in assessment of molecular diversity may be useful. Comparison among the organisms or on a larger scale of family may further be taken to give insight on the molecular journey of the organisms. Present paper deals with the study of COX-1 in four families viz., Gyrodactylidae, Diplectenidae, Diplozoidae and Dictilophoridae (Class : Monogenea) using structural and other significant parameters. In all 16 species have been extensively studied across four families. Results reflecting peculiar diversity on molecular level suggesting divergence based evolution in the form of molecular molding.