Physiological condition and differential feeding behaviour in the cryptic species complex Eurytemora affinis in the St Lawrence estuary

摘要: The cryptic species complex, Eurytemora affinis is an important component of the mesozooplankton estuarine transition zones (ETZs). In St Lawrence ETZ, two clades, Atlantic and North-Atlantic clades co-occur. However, their distribution along environmental gradients spatially segregated, potentially because differential habitat exploitation. this study, we tested hypotheses on geographic disparity E. populations, each belonging to one clades. First, habitats differ in food composition availability, second, clade populations shows a distinct feeding behaviour, both, influencing physiological condition. To achieve goal, used fatty acid (FA) approach determine FA sources affinis. Its condition was estimated by concentration accumulated neutral FAs. Our results revealed that availability were similar between habitats, suggesting resource conditions did not contribute spatial segregation populations. both characterized high levels docosahexaenoic eicosapentaenoic acid, they predominantly ingested phytoplankton. significantly different profiles suggested which may optimize accumulation energy reserves relation needs. Both seem show good conditions, being well adapted dynamic environment ETZ.