Almost all marine ecosystems have Mollusca members for their balanced continued functioning. While some may seem harmless or even gentle, others are equipped with powerful weapons like venomous tentacles to fend off predators. Mollusks are considered an important subject of research in various fields due to their unique biology and ecological significance. Their research has many implications in areas such as medicine and biotechnology. Numerous species have recently been the subject of research, with numerous secondary metabolites being isolated and their chemical structures being clarified. Natural substances that were poisonous to tumor cells, harmful bacteria, viruses, and others have been discovered. Some isolated compounds constituted the active ingredients in medicinal preparations used in clinical practice, while others are still in various stages of preclinical research. These substances often lacked equivalents in other naturally occurring substances with terrestrial origin. Metagenomics tools has simplified the discoveries in this field and with the help of metagenomics, we could identify new genes and proteins to be used in biotechnology applications, such as the development of new drugs.