Isotopic Niche and Trophic Position of the Invasive Portunid Portunus segnis Forskål, (1775) in Elounda Bay (Crete Island, Eastern Mediterranean)

There is a growing recognition that an advanced understanding of the trophic characteristics invasive consumer can provide important information on its ecological impact. In recent years, blue swimming crab Portunus segnis, one earliest Lessepsian invaders, has considerably expanded distribution range in Mediterranean Sea, yet, habits invaded areas remain scarcely investigated. this study, we used carbon and nitrogen stable isotopes analysis (SIA) to determine position isotopic niche compared with other representatives flora fauna occurring Elounda Bay (Crete). P. segnis showed 3.9, higher than values determined by SIA or conventional gut content Sea native range. Crab specimens high inter-individual variability both δ13C δ15N values; further indicated negligible differences adult males females. Conversely, were significantly related size specimens, ultimately suggesting ontogenetic dietary shift. This study represents first attempt characterize context food web may contribute implementation long-term management strategies control mitigation