The Asian clam Corbicula fluminea has
been widely introduced into aquatic ecosystems and
may impact the physiological condition and survival
of native freshwater mussels. However, very few studies
have evaluated this issue quantitatively. To fill
this gap, manipulative field experiments were performed
to assess two possible mechanisms of impact
on native mussels: (i) interspecific interactions, and
(ii) C. fluminea die-offs. We assessed these effects by
measuring the physiological condition through the
analysis of glycogen content in the foot tissue of the
native freshwater mussel species Anodonta anatina,
Potomida littoralis, and Unio delphinus. Although
with interspecific differences, our results suggest that
C. fluminea can impact the physiological condition of
native freshwater mussels. Anodonta anatina showed
positive significant variations on glycogen content
when subjected to high densities of live C. fluminea
in contrast to the other native species studied, P. littoralis
and U. delphinus, where no significances were
observed. On the other hand, these native species do
not seem be significantly impacted by the decomposition
of C. fluminea resulting from a die-off. Overall,
and contrary to our expectations, both experiments
showed a positive (or no) effect of C. fluminea on the
physiological condition of the three freshwater mussel
species.
