title: Use of isotopic analysis of vertebrae in reconstructing ontogenetic feeding ecology in white sharks.
abstract: We conducted stable 13C and 15N analysis on white shark vertebrae and demonstrated that incremental analysis of isotopes along the radius of a vertebral centrum produces a chronological record of dietary information, allowing for reconstruction of an individual's trophic history. Isotopic data showed significant enrichments in 15N with increasing sampling distance from the centrum center, indicating a correlation between body size and trophic level. Additionally, isotopic values verified two distinct ontogenetic trophic shifts in the white shark: one following parturition, marking a dietary switch from yolk to fish; and one at a total length of >341 cm, representing a known diet shift from fish to marine mammals. Retrospective trophic-level reconstruction using vertebral tissue will have broad applications in future studies on the ecology of threatened, endangered, or extinct species to determine life-long feeding patterns, which would be impossible through other methods.
authors: Department of Biological Sciences, University of New England, Biddeford, Maine 04004, USA.
authors: James A
authors: JA
authors: Estrada
authors: Aaron N
authors: AN
authors: Rice
authors: Lisa J
authors: LJ
authors: Natanson
authors: Gregory B
authors: GB
authors: Skomal