Abstract
Cephalopods and elasmobranchs are important components of marine ecosystems, whereby knowing the ecological role they play in the structure and dynamics of trophic networks is paramount. With this aim, stomach contents and stable isotopes of the most abundant elasmobranch and cephalopod species (5 and 18 species, respectively) inhabiting deep-sea ecosystems from the western Mediterranean were analyzed. The predators investigated encompassed different taxonomic groups, such as rays and sharks within elasmobranchs, and squids, octopuses and cuttlefishes within cephalopods. Specifically, we investigated ontogenetic shifts in diet, feeding strategies and prey consumption, trophic structure and potential dietary overlap between and within both taxonomical groups. Stable isotope analysis revealed ontogenetic shifts in diet in three elasmobranch (rays and sharks) and two cephalopod (octopuses and squids) species. Isotopic data showed a contrasting food source gradient (δ13C), from pelagic (squids and cuttlefishes) to benthic (octopuses and elasmobranchs). Stomach data highlighted a great variety of trophic guilds which could be further aggregated into three broad categories: benthic, benthopelagic and pelagic feeders. The combination of both stomach content and stable isotope analyses revealed a clear food partitioning among species. Mesopelagic prey were found to be an important food resource for deep-sea elasmobranchs and cephalopods, which could be related to the strong oligotrophic conditions in the area. The observed differences in feeding strategies within cephalopods and elasmobranchs should be taken into account when defining functional groups in trophodynamic models from the western Mediterranean. Our results also revealed that cephalopods play a key role for the benthopelagic coupling, whereas demersal elasmobranchs contribute primarily to a one-way flux accumulating energy resources into deep-sea ecosystems.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Deep Sea Research Part I: Oceanographic Research Papers
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
