|Feeding ecology of five commercial shark species of the Celtic Sea through stable isotope and trace metal analysis|
|Domi, N.; Bouquegneau, J.-M.; Das, K. (2005). Feeding ecology of five commercial shark species of the Celtic Sea through stable isotope and trace metal analysis. Mar. Environ. Res. 60(5): 551-569. dx.doi.org/10.1016/j.marenvres.2005.03.001|
|In: Marine Environmental Research. Applied Science Publishers: Essex. ISSN 0141-1136, more|
Carnivores; Feeding behaviour; Isotopes; Stomach content; Trace metals; Trophic levels; Elasmobranchii [WoRMS]; Galeorhinus galeus (Linnaeus, 1758) [WoRMS]; Galeorhinus galeus (Linnaeus, 1758) [WoRMS]; Galeus melastomus Rafinesque, 1810 [WoRMS]; Mustelus asterias Cloquet, 1819 [WoRMS]; Mustelus asterias Cloquet, 1819 [WoRMS]; Scyliorhinus canicula (Linnaeus, 1758) [WoRMS]; Squalus acanthias Linnaeus, 1758 [WoRMS]; ANE, Celtic Sea [gazetteer]; Marine
elasmobranchs; stable isotopes; trace metals; trophic level; Celtic Sea; Galeorhinus galeus; Galeus melastomus; Mustelus asterias; Squalus acanthias; Scyliorhinus canicula
In order to trace their feeding habits, stable carbon and nitrogen isotope ratios (d15N and d13C), as well as trace metal concentrations (Zn, Cd, Fe, Cu, Se and Hg) were analysed in the tissues of five commercial shark species from the Celtic Sea: the tope shark Galeorhinus galeus, the black-mouthed catshark Galeus melastomus, the starry smooth hound Mustelus asterias, the spiny dogfish Squalus acanthias and the lesser-spotted dogfish Scyliorhinus canicula. Our results were compared to previously described stomach contents and isotopic composition of potential preys. Isotopic ratio d15N suggested that tope sharks fed at a higher trophic level (16.7‰ in the muscle) than the other species, reflecting its piscivorous diet. The lower values of spiny dogfish (11.6‰ in the muscle) might be explained, amongst other things, by either its migratory behaviour or its preference for preys from lower trophic levels. Cd and Hg were correlated with isotopic ratios d13C and d15N, and were shown to be diet-related whereas Zn, Fe and Cu seemed much more linked to species-specific metabolism. Although this multidisciplinary approach is revealed as a useful tool for the study of shark ecology, the lack of known trophic fractionation suggests that isotopic data be compared to traditional diet analyses.