This study reports the occurrence of Marphysa mossambica (Peters, Akademie der Wissenschaftenzu Berlin, Monatsberichten 1854:610–614, 1854) from Worli, Mumbai, India, and presents comprehensive hydro-sedimentological data characterizing its habitat. The collected specimen was identified belonging to the genus Marphysa, characterized by the presence of two palps, three antennae, a bilobed prostomium, and a median antenna measuring approximately 1.5 times the length of the prostomium. Due to the high incidence of morphological misidentification within the genus, a specific molecular identification protocol based on the partial sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene was standardized for Marphysa mossambica, and the resulting sequence has been deposited in the NCBI database. Although Marphysa mossambica has previously been reported from the coasts of the Bay of Bengal and the Arabian Sea, those records were based solely on morphological characteristics and lacked molecular confirmation. Marine polychaetes are predominantly harvested from the wild for use in bait fisheries and are also extensively utilized as a vital live feed in the aquaculture industry. Therefore, promoting the cultivation of polychaetes should be considered a sustainable management strategy to reduce dependence on wild populations.
