Ontogenic changes in habitat and trophic ecology in the Antarctic squid Kondakovia longimana derived from isotopic analysis on beaks

• Published in: Polar Biology
• Main Authors: Queirós, José, Cherel, Yves, Ceia, Filipe, Hilário, Ana, Roberts, Jim, Xavier, José
• Other Authors: Campus Universitario de Santiago, Universidade de Aveiro, MARE – Marine and Environmental Sciences Centre, da Universidade de Coimbra, Coimbra, Portugal, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Marine and environmental research centre - IMAR-CMA (Coimbra, Portugal), University of Coimbra Portugal (UC), Departamento de Biologia (CESAM), National Institute of Water and Atmospheric Research Wellington (NIWA), British Antarctic Survey (BAS), Natural Environment Research Council (NERC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Cephalopoda; Southern Ocean; Onychoteuthidae; Kondakovia longimana; Antarctica; [SDE]Environmental Sciences; Antarctic; The Antarctic; The Beak; Antarc*; Antarctic Squid; Polar Biology
• Online Access: https://hal.science/hal-02020453; https://doi.org/10.1007/s00300-018-2376-4

International audience The life histories of cephalopods are still not well described. Stable isotopic analysis of cephalopod beaks is an effectivemethod to study the habitat and trophic ecology of this group of organisms. As beaks grow continuously throughout squid’slife without replacement, we hypothesised that analysing different sections along the beak will provide information on theontogenetic shifts during the individual’s lifetime. Here we used the Southern Ocean squid Kondakovia longimana as amodel species to test the reliability of this method along the beaks of Antarctic species. Growing patterns show that beaksgrow throughout the squid lifetime by a continuous deposition of material. This new material can influence the results ofthe stable isotopic analysis. δ13C and δ15N values (from − 26.3 to − 20.6‰ and from + 3.2 to + 8.2‰, respectively) fromdifferent beak regions indicated that K. longimana inhabits regions spanning a wide latitudinal range, and the trophic levelat which it feeds increases throughout its lifetime. Stable isotopic analysis of different sections of the cephalopod beak is areliable technique to study habitat and trophic ecology throughout Antarctic squid’s lifetime. Stable isotopic results showedan increase in δ15N values from the tip of the rostrum to the end of the hood and crest, in the upper beak, and to the freecorner of lateral wall and wing in the lower beak. Our results also suggested that the upper beak is the best beak to studyontogenetic shifts, mainly in initial stages of the cephalopods’ life, presenting lower values of δ15N than the lower beak.