Host manipulation of a freshwater crustacean (Gammarus roeseli) by an acanthocephalan parasite (Polymorphus minutus) in a biological invasion context

An acanthocephalan parasite increases the salinity tolerance of the freshwater amphipod Gammarus roeseli (Crustacea: Gammaridae)

“…All the individual gammarids used in this study were collected at the same time in June 2005 in the Nied River and from the same site (Laquenexy, northeastern France, 49°05′N and 6°19′E; Médoc et al 2006). Within a set of 3,247 amphipods examined, 440 contained P. minutus cystacanths, which represented a prevalence rate of 13.5%.…”

Acanthocephalan parasites: help or burden in gammarid amphipods exposed to cadmium?

“…Among the numerous complex life cycle parasites, acanthocephalans are known to alter the phenotype of their intermediate hosts in a way that make it more prone to predation and thus, favour its transmission to the final vertebrate host (Kennedy 2006;Lagrue et al 2007). If behavioural changes induced by the parasite have been intensively studied (Cézilly et al 2000;Bauer et al 2005;Médoc et al 2006), the modifications of host antitoxic responses has become a topic of interest in a context of rising pollution in freshwater ecosystems. Sures and Radszuweit (2007) described that the cystacanth stage of Polymorphus minutus prevented the synthesis of heat shock protein 70 in G. roeseli, when subjected to a thermal disturbance or a palladium exposure.…”

“…We tested our hypothesis in the widespread amphipod G. roeseli, an intermediate host for the acanthocephalan parasite P. minutus, which modifies the gammarid behaviour (Médoc et al 2006;Médoc and Beisel 2009). We first studied the influence of the acanthocephalan parasite P. minutus on the lethal concentration 50 of cadmium (LC 50 -concentration that caused the death of 50% of individuals) reflecting the resistance of the gammarid host.…”

Does the acanthocephalan parasite Polymorphus minutus modify the energy reserves and antitoxic defences of its intermediate host Gammarus roeseli?

“…The behavioural changes induced by acanthocephalans can vary and include reaction to light (Bauer et al 2000;PerrotMinnot, 2004), vertical distribution Bauer et al 2005;Médoc et al 2006), drift behaviour (McCahon et al 1991;Maynard et al 1998), activity level or the refuge use and the escape performance faced with non-host predators (Baldauf et al 2007;Perrot-Minnot et al 2007;Beisel and Médoc, 2010). Behavioural changes make gammarids more likely to be preyed upon by the parasite's final host (Lagrue et al 2007;Perrot-Minnot et al 2007;Cézilly et al 2010).…”