Species-specific variation in cuttlebone delta C-13 and delta O-18 for three species of Mediterranean cuttlefish
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Stable carbon (13C) and oxygen (18O) isotopes in cuttlebones of three species of Mediterranean cuttlefish (Sepia elegans, S. officinalis, and S. orbignyana) with different life histories were contrasted. Cuttlebone 13C and 18O were quantified at both the core and edge (representing early life and recent deposition, respectively) for all three species sampled from the southern Adriatic Sea in 2010 (n = 28). For S. officinalis, cuttlebone 13C and 18O values were both lower relative to S. elegans and S. orbignyana at the core by approximately 1.0-2.0 and 3.0 , respectively. Differences between core and edge in cuttlebone 13C and 18O were also observed for S. officinalis with observed values at the cuttlebone edge (recent) exceeding core (early life) values by 2.5 for 13C and 1.4 for 18O. Differences in isotopic composition across S. officinalis cuttlebones are possibly reflective of ontogenetic migrations from nearshore nurseries (lower seawater 13C and 18O values) to offshore overwintering habitats (higher seawater 13C and 18O values). Overall, results from this study suggest that cuttlebone 13C and 18O hold promise as natural tags for determining the degree of spatial connectivity between nearshore and offshore environments used by cuttlefish. 2013 Springer-Verlag Berlin Heidelberg.