%0 Journal Article
%T Understanding invasion success: life-history traits and feeding habits of the alien crayfish Orconectes immunis (Decapoda, Astacida, Cambaridae) Comprendre le succ¨¨s d'invasions : traits d¡¯histoire de vie et habitudes alimentaires de l¡¯¨¦crevisse non-indig¨¨ne Orconectes immunis (Decapoda, Astacida, Cambaridae)
%A Chucholl C.
%J Knowledge and Management of Aquatic Ecosystems
%D 2012
%I EDP Sciences
%R 10.1051/kmae/2011082
%X In the present study, the life history and diet of the highly successful North American invader Orconectes immunis was assessed for the first time in its introduced European range. In 2007, O. immunis population dynamics were monitored in a typical backwater habitat using unbaited funnel traps, and its life history was analysed using Von Bertalanffy¡¯s growth function. Juveniles hatched as early as March and may attain sexual maturity at the end of their first summer. The adult population moulted up to four times during the summer months, with the non-breeding form (II) lasting for a remarkably short time period. The high growth rate of O. immunis was combined with a short longevity, which was estimated at 2.5 years. The fecundity ranged from 119 to 495 pleopodal eggs. The stomach contents were dominated by detritus, followed by macroinvertebrates and macrophytes, and no ontogenetic shift in diet was observed. The ability to prey on a wide array of invertebrate taxa presumably supports the sustained high growth rate of O. immunis. The presented data provide evidence that O. immunis exhibits a strongly r-selected life history and omnivorous feeding habits. These ecological properties have often been linked to successful invaders and enhance the invasiveness of O. immunis. Dans la pr¨¦sente ¨¦tude, l'histoire de vie et le r¨¦gime alimentaire d¡¯Orconectes immunis, esp¨¨ce fortement invasive d¡¯Am¨¦rique du Nord ont ¨¦t¨¦ ¨¦valu¨¦s pour la premi¨¨re fois dans la r¨¦gion europ¨¦enne d¡¯introduction. En 2007, la dynamique de la population d¡¯O. immunis a ¨¦t¨¦ suivie dans un habitat typique de bras mort ¨¤ l'aide de pi¨¨ges en entonnoir non appat¨¦s, et son histoire de vie a ¨¦t¨¦ analys¨¦e en utilisant la fonction de croissance de Von Bertalanffy. Les juv¨¦niles ¨¦closent d¨¨s mars et peuvent atteindre la maturit¨¦ sexuelle ¨¤ la fin de leur premier ¨¦t¨¦. La population adulte mue jusqu'¨¤ quatre fois pendant les mois d'¨¦t¨¦, avec la forme de non-reproduction (II) d'une p¨¦riode de temps remarquablement courte. Le taux de croissance ¨¦lev¨¦ d¡¯O. immunis est associ¨¦ ¨¤ une long¨¦vit¨¦ courte, estim¨¦e ¨¤ 2,5 ans. La f¨¦condit¨¦ varie de 119 ¨¤ 495  ufs pl¨¦opodaux. Les contenus stomacaux sont domin¨¦s par des d¨¦tritus, suivis par les macroinvert¨¦br¨¦s et les macrophytes, et aucun changement ontog¨¦n¨¦tique dans le r¨¦gime alimentaire n¡¯a ¨¦t¨¦ observ¨¦. La capacit¨¦ ¨¤ se nourrir sur un large ¨¦ventail de taxons d'invert¨¦br¨¦s soutient vraisemblablement le taux de croissance ¨¦lev¨¦ d¡¯O. immunis. Les donn¨¦es pr¨¦sent¨¦es d¨¦montrent que O. immunis pr¨¦sente une histoire de vie de strat¨¨ge r et des habitudes alimentaires
%K r-selected species and life history
%K non-indigenous crayfish
%K polytrophic omnivore
%K esp¨¨ces ¨¤ strat¨¦gie r et histoire de vie
%K ¨¦crevisse non-indig¨¨ne
%K omnivorie polytrophique
%U dx.doi.org/10.1051/kmae/2011082