Whole genome sequencing is completed for Argonauta argo, a mysterious octopus with a shell

A research group led by Associate Professor Mas-aaki Yoshida of Shimane University’s Oki Marine Station has published their research result, “Success in decoding the whole genome of Argonaut, a mysterious octopus with a shell – New findings on the origin and evolution of the shell,” was published in the online edition of the international journal Genome Biology and Evolution on Wednesday, October 26, 2022.
Argonaut shells are known to wash up in various locations along the Sea of Japan in winter, and are among the most prized shells found on beaches. These shells are known to be made by members of the octopus family. The research group has now decoded the entire genome sequence of Argonaut argo, a species of octopus, for the first time in the world. Of the 26,433 genes in the Argonaut genome, 44 genes were found to be used for shell formation. Furthermore, they found changes in genes in the genome that may have occurred during the transition of the Argonaut from a benthic to a pelagic life. This has led to the discovery of a major evolutionary mystery: How did the octopus, which supposedly lost its shell during the evolutionary process, come to be able to produce shells again? This is one step closer to solving the great evolutionary mystery of how the octopus lost its shell in the process of evolution and how it came to be able to make shells again.

The results of the study were covered by the following international media.