Oxygen consumption, temperature and salinity tolerance of the invasive amphipod Dikerogammarus villosus: indicators of further dispersal via ballast water transport
Bruijs, M. C. M.; Kelleher, B.; van der Velde, G.; Bij de Vaate, A.
published: Jan 10, 2001
ArtNo. ESP141015204013, Price: 29.00 €
The Ponto-Caspian amphipod, Dikerogammarus villosus is a recent and successful invader of the River Rhine. It has dispersed over large distances in a short time. As it has an extensive invasion history in Europe, it is thought to have potential to reach and invade the Great Lakes in America. However, for this it must survive the stress of high salinity during ballast water exchange. Therefore, several aspects of the general ecophysiology of D. villosus were studied by means of laboratory experiments. Highest oxygen consumption occurred around 20 °C. This result is supported by the pleopod beat frequency measurements, showing a maximum around 20 °C. Our results indicate that D. villosus has a wide temperature tolerance. Salinity tolerance experiments demonstrated that salinities of 25 ‰ and higher are lethal toD. villosus. However, D. villosus survived at salinities up to 10 ‰ and adapted to salinities of up to 20 ‰ within 10 days. Ballast water exchange will thus only act as an appropriate biocide against D. villosus, when salinities reach at least 25 ‰. These results indicate that D. villosus is an euryhaline, eurythermic species, similar to most immigrants inhabiting the River Rhine. By these capacities for adaptation D. villosus may be able to survive (incomplete) ballast water exchange and subsequently be dispersed over large distances by means of ballast water and to develop large populations in temperate areas on a global scale.