In the rainforest of an uninhabited island in the Republic of Palau in the western Pacific Ocean, sea slugs that landed on land were found for the first time in the world.Nudibranchs are a family of shellless snails that live in shallow waters and at the bottom of rivers and are distributed all over the world, but they seem to have adapted to land life on this island.The discovered group of Associate Professor Yasunori Kano of the Atmosphere and Ocean Research Institute of Tokyo and Hiroaki Fukumori, Associate Researcher of Marine Science, will make a presentation in the academic journal "Biological Journal" of the London Linne Association of the United Kingdom.
Sea slugs have a kidney with a simple structure and urinate through its opening, whereas land slugs drain from the kidney through a long nephridium.This kidney tube seems to have the function of reabsorbing salt from urine, which tends to be deficient in land life.Sea slugs hatch as plankton larvae and grow and metamorphose into sea slugs, while land sea slugs are born in the same shape as their parents.
The uninhabited island where the land sea slugs were located is covered with a humid rainforest.It is inhabited by slugs and large animals on the ground, and has no competitors or predators.It is believed that these points made it possible for sea slugs to advance to land.
* A general term for species of opisthobranchia belonging to the sea slug mollusk gastropod (a member of the snail) whose shells have shrunk or disappeared.Includes Aplysia, Aplysia, Nudipreura, etc.
Source:[Atmosphere and Ocean Research Institute, University of Tokyo] Discovery of land sea slug