摘要：Dikerogammarus villosus has been recorded for the first time in the alpine lake � Lac du Bourget, French Alps. Low abundance of the alien species in gathered samples suggests that the colonization is just in its initial stage. Two native gammarid species: Gammarus fossarum (Koch, 1836) and G. pulex (Linnaeus, 1758) are still present in the lake. The invader has most probably reached the lake through the Canal de Savi�res joining the lake to the Rhone River in which it has been already present since late 1990s.
