Elemental classification of the tusks of dugong (Dugong dugong) by HH-XRF analysis and comparison with other species

Korakot Nganvongpanit,Promporn Piboon,Thippaporn Euppayo,Chatchote Thitaram,Kongkiat Kittiwatanawong,Phaothep Cherdsukjai,Kittisak Buddhachat,Patcharaporn Kaewmong

doi:10.1038/srep46167

Korakot Nganvongpanit, Promporn Piboon + Show 6 more

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https://doi.org/10.1038/srep46167

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Abstract

The elemental composition was investigated and applied for identifying the sex and habitat of dugongs, in addition to distinguishing dugong tusks and teeth from other animal wildlife materials such as Asian elephant (Elephas maximus) tusks and tiger (Panthera tigris tigris) canine teeth. A total of 43 dugong tusks, 60 dugong teeth, 40 dolphin teeth, 1 whale tooth, 40 Asian elephant tusks and 20 tiger canine teeth were included in the study. Elemental analyses were conducted using a handheld X-ray fluorescence analyzer (HH-XRF). There was no significant difference in the elemental composition of male and female dugong tusks, whereas the overall accuracy for identifying habitat (the Andaman Sea and the Gulf of Thailand) was high (88.1%). Dolphin teeth were able to be correctly predicted 100% of the time. Furthermore, we demonstrated a discrepancy in elemental composition among dugong tusks, Asian elephant tusks and tiger canine teeth, and provided a high correct prediction rate among these species of 98.2%. Here, we demonstrate the feasible use of HH-XRF for preliminary species classification and habitat determination prior to using more advanced techniques such as molecular biology.

Highlights

The dugong (Dugong dugon, Müller), or sea cow, is one of four herbivorous marine mammal species surviving in the family Dugongidae, order Sirenia
We found that dugong tusks could be completely discriminated from Asian elephant tusks and tiger canine teeth, while some Asian elephant tusks were predicted as tiger teeth (0.7%) and some tiger teeth were predicted as dugong tusks (2.6%) and Asian elephant tusks (26.3%)
The elemental composition of biological materials is useful in a wide range of sciences

Summary

Introduction

The dugong (Dugong dugon, Müller), or sea cow, is one of four herbivorous marine mammal species surviving in the family Dugongidae, order Sirenia. A previous study in female dugongs analyzed elements in the 55 annual incremental longitudinal sections of tusks, and reported the presence of nine elements: barium (Ba), lithium (Li), sodium (Na), calcium (Ca), iron (Fe), magnesium (Mg), phosphorus (P), strontium (Sr) and zinc (Zn)[12]. Most elements revealed both long-term trends and shorter, year-to-year, variation. Trade in dugong parts such as tusks is difficult to detect For this reason, the use of elemental analysis needs to be developed as a tool for identifying and differentiating dugong tusks from other valuable animal wildlife materials: Asian elephant (Elephas maximus) tusks and tiger (Panthera tigris tigris) canine teeth

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