Lithoglyphus naticoides (Pfeiffer) (Gastropoda: Prosobranchia) : distribution in France, population dynamics and life cycle in the Saône river at Lyon (France)

Lithoglyphus naticoides was observed for the first time in the north of France at the beginning of the 19th century, but since then this gastropod has only succeeded in colonising the eastern half of this country. A map showing its distribution in France is proposed. In the Saone river, L. Naticoides is an annual species: spawning occurs from March to June and the juveniles that generally appear in May grow rapidly during the summer then spawn and disappear in the spring of the following year. Different observations suggest that increased water temperatures occurring in the context of global warming and potential/possible interspecific competition are the main reasons for the disappearance of L. Naticoides in the Saone river at Lyon since November 2004.