The rediscovery of the lesser ramshorn snail has yielded new insights for conservation
In 2025, a very small freshwater snail made big news in the Demer Valley. The lesser ramshorn snail was discovered in a stream in the Aarschot region – a species thought to have disappeared from Belgium. The discovery confirmed, for the first time in a long while, that the species still occurs in our country. Moreover, this is currently the only recently known population in Belgium.
The lesser ramshorn snail is protected at European level under the Habitats Directive. In Flanders, it is one of the species we monitor through the Species Monitoring Networks. In 2018, INBO identified knowledge gaps concerning four rare, European-protected molluscs, including the lesser ramshorn snail. As there had been no recent sightings, little was known about the conditions under which the species can survive in Flanders today. The rediscovery therefore offered a unique opportunity to study its habitat in detail.
In June 2026, researchers from INBO and Natuurpunt Studie therefore carried out a detailed survey of the stream. They found living lesser ramshorn snails at three of the four sites surveyed. At two sites, the numbers were even substantial. Their habitat was described on the basis of the vegetation, the vegetation structure and the characteristics of the water.
The results help to provide a better understanding of the conditions required by this rare snail. This will enable conservation and management measures to be better tailored and will also facilitate a targeted search for any other populations in Flanders.
Ward Langeraert, Jo Packet