Abstract: Opisthobranchs are the least studied group of animals in the phylum Mollusca in context to the Indian subcontinent. They are one of the best indicators of the reef resilience. Melibe viridis Kellart (1858) belonging to subclass Opisthobranchia has been recorded from the reefs of Gulf of Kachchh only in the west coast of India. The current paper describes the first record of spawning aggregation of the species in the Gulf of Kachchh in the western India.