Exploring diet shifts and ecology in modern sharks using calcium isotopes and trace metal records of their teeth
Assemat, A.; Adnet, S.; Bayez, K.; Hassler, A.; Arnaud-Godet, F.; Mollen, F.H.; Girard, C.; Martin, J.E. (2022). Exploring diet shifts and ecology in modern sharks using calcium isotopes and trace metal records of their teeth. J. Fish Biol. Early view. https://dx.doi.org/10.1111/jfb.15211 In: Journal of Fish Biology. Fisheries Society of the British Isles: London,New York,. ISSN 0022-1112; e-ISSN 1095-8649, more |  |
| Keywords | Elasmobranchii [WoRMS]
Marine/Coastal | | Author keywords | alkaline metals, calcium, ecology, elasmobranchs, ontogeny, trophic level |
| Authors | | Top | - Assemat, A.
- Adnet, S.
- Bayez, K.
- Hassler, A.
| - Arnaud-Godet, F.
- Mollen, F.H., more
- Girard, C.
- Martin, J.E.
| |
| Abstract | Sharks occupy all living environments of the marine realm as well as some freshwater systems. They display varied and flexible feeding behaviours, but understanding their diet remains challenging due to their elusive ecology and the invasiveness of stomach content analyses in regard of their threatened status. As a potential alternative, we discuss the variability in δ44/42Ca values recorded in the tooth enamel of size-graded individuals belonging to three species of large sharks with distinct diets (Isurus oxyrinchus, Hexanchus griseus and Carcharodon carcharias). The preliminary results highlight shifts in diet linked to ontogeny (I. oxyrinchus and H. griseus) and spatial distribution (C. carcharias) characterizing feeding behaviour in these species at individual and population level. These outcomes agree with the results of traditional stomach analyses supporting that nontraditional stable isotopes thus represent new perspectives for the study of modern and extinct shark ecology. In addition, for the first time, the Sr/Ca elemental ratios measured in H. griseus reflect sexual differences that could be interpreted in terms of spatial segregation or physiological heterogeneities. |
|
