文摘
Species invasions can have profound ecological impacts, including changes in patterns of distribution, abundance and diversity of native species, altering food-web dynamics and ecosystem functioning. In the marine benthic environment temperature, predation, competition for space and wave action exposure are some of the main factors that determine invasion success; however, the importance of food availability for invasive species has been underestimated. The present study investigates the diets of two mussel species, Mytilus galloprovincialis and Perna perna, that occur in mixed-species mussel beds, using fatty acid (FA) and stable isotope (SI) approaches over two periods of time in 2012 and 2014. With the exception of one site, we found no significant differences in the SI signatures between species, while strong dissimilarities were present in their FA signatures. Both species showed signatures of exposure to good food quality, however, neither showed links to specific dietary trophic markers. The FA differences observed between species could be related to food selectivity by one or both species or more likely by different metabolic pathways. Further investigations are needed to clarify the pattern observed; however, the results suggested that the food environment was not an important factor in determining the success of the invasive species.
