How do organisms with low mobility expand their distribution?Until now, many organisms with distributions that cannot be explained without assuming long-distance migration across the ocean are known.Regarding the migration mechanism, it was presumed that birds were responsible for long-distance migration of thousands of kilometers.However, no direct evidence for long-distance migration via birds has been provided so far, and the evidence for this is scant.

　In the spring of 2022, the research group discovered snails attached to the body surface of a giant snipe captured in Chiba Prefecture.Examination of the morphology of this snail and molecular phylogenetic analysis revealed that this snail is included in the genus Glyptophysa, phylum Gastropoda, family Glyptophyta, molluscs.There is no record in Japan, and it is distributed from Oceania to the Philippines.On the other hand, the giant sandpiper comes to Japan from Oceania in the spring to breed, but it is said that it flies continuously for several days without landing on the ground before reaching Japan.It is believed that the snail attached to the giant snipe somewhere in Oceania and flew more than 4000 km on its body before arriving in Japan.

　Based on the evidence of molecular identification, there are no cases demonstrating extracorporeal transport by birds from outside their habitat, and the migration of snails discovered this time is a class of examples of naturally occurring long-distance migration of organisms by attachment of birds. It is said to not see.The results provide strong evidence for a long-distance migration mechanism mediated by birds that has remained speculative until now.

Paper information:[Ecography] Direct evidence for intercontinental dispersal of a snail via a bird