Presence of Palaemon macrodactylus in a Europe estuary: evidence for a successful invasion of the Gironde (SW France)

Mélanie Béguer (1) , J. Bergé (2) , J. Martin (1) , J. Martinet (1) , G. Pauliac (3) , Michel Girardin (1) , Philippe Boët (1)

1 UR EPBX - Ecosystèmes estuariens et poissons migrateurs amphihalins
2 UR MALY - Milieux aquatiques, écologie et pollutions
3 EPOC - Environnements et Paléoenvironnements OCéaniques

Palaemon macrodactylus, an exotic shrimp native to the northwest Pacific Ocean, has been recorded in many estuaries along the Atlantic coast of Europe since the late 1990’s. In this study, a regular monthly survey, held since 1992 of the middle section of the Gironde estuary, revealed this species’ rapid and full colonization of the system since its appearance in samples during summer 1998. In the Gironde, the population of P. macrodactylus is self-sustaining and the species is now established there. Our study highlights two important elements that might explain its successful colonization: its ability to quickly invade a niche under-exploited by the similar native species and its greater reproductive output. The species’spatio-temporal distribution in relation to environmental variables was studied and compared with that of the native species P. longirostris. The exotic species was shown to mainly inhabit the polyhaline and mesohaline section of the estuary, which are sections generally under-exploited by females of the native species. Furthermore, fecundity analysis and larval abundance survey results revealed a higher potential fecundity and a greater proportion of larvae and juvenile stages for P. macrodactylus in the natural environment.

Mots clés: PALAEMON MACRODACTYLUS; PALAEMON LONGIROSTRIS; ESTUAIRE; HISTORIQUE; INVASION BIOLOGIQUE

Domaines: Sciences de l'environnement

Mélanie Béguer, J. Bergé, J. Martin, J. Martinet, G. Pauliac, et al.. Presence of Palaemon macrodactylus in a Europe estuary: evidence for a successful invasion of the Gironde (SW France). Aquatic Invasions, 2011, 6 (3), p. 301 - p. 318. ⟨10.339/ai.2011.6.3.07⟩. ⟨hal-00669971⟩