Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary implications


  • Mónica Revelles Dept. of Animal Biology, Faculty of Biology, University of Barcelona, Barcelona
  • Luis Cardona Dept. of Animal Biology, Faculty of Biology, University of Barcelona, Barcelona
  • Alex Aguilar Dept. of Animal Biology, Faculty of Biology, University of Barcelona, Barcelona
  • Assumpció Borrell Dept. of Animal Biology, Faculty of Biology, University of Barcelona, Barcelona
  • Gloria Fernández Fundación AsproNatura, Mallorca
  • Manuel San Félix Department of Zoology, Faculty of Biology, University of Valencia, Valencia



tissues, stable isotopes, sea turtle, trophic level, feeding ecology, carbon, nitrogen


The isotopic concentrations of carapace scutes, skin, muscle and blood of loggerhead sea turtles (Caretta caretta) from the Balearic Archipelago were analysed to investigate the pattern of variation between tissues and to assess the position of this species in the trophic webs of the Algerian Basin. Skin showed higher δ13C values than muscle or carapace scutes and these showed higher values than blood. Conversely, muscle showed higher δ15N values than skin, skin showed higher values than blood and blood showed higher values than carapace scutes. Dead and live sea turtles from the same habitat did not differ in the concentration of stable isotopes. However, some of the tissues of the turtles caught in drifting longlines in the oceanic realm showed higher δ13C values than those from the turtles caught by hand or in trammel nets over the continental shelf, although they did not differ in the δ15N. Comparison of the concentration of stable isotopes in the turtles with that of other species from several areas of the Algerian Basin revealed that they consumed planktonic prey and that the trophic level of the sea turtles was higher than that of carnivorous cnidarians but lower than that of zooplanktophagous fish and crustaceans.


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How to Cite

Revelles M, Cardona L, Aguilar A, Borrell A, Fernández G, San Félix M. Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary implications. Sci. mar. [Internet]. 2007Mar.30 [cited 2024Feb.21];71(1):87-93. Available from:




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