Age-related changes in size, bone microarchitecture and volumetric bone mineral density of the mandible in the harbor seal (Phoca vitulina)

Autoři: Patricia Kahle aff001;  Tim Rolvien aff002;  Horst Kierdorf aff001;  Anna Roos aff004;  Ursula Siebert aff005;  Uwe Kierdorf aff001
Působiště autorů: Department of Biology, University of Hildesheim, Hildesheim, Germany aff001;  Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany aff002;  Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany aff003;  Department of Contaminant Research, Swedish Museum of Natural History, Stockholm, Sweden aff004;  Institute of Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Hannover, Germany aff005
Vyšlo v časopise: PLoS ONE 14(10)
Kategorie: Research Article
doi: 10.1371/journal.pone.0224480


Detailed knowledge of age-related changes in the structure and mineralization of bones is important for interpreting osseous changes in wild mammals caused by exposure to environmental contaminants. This study analyzed mandibular size, microarchitecture and volumetric bone mineral density (vBMD) in harbor seals (n = 93, age range 0.5 months to 25 years) from the German North Sea. Bone microarchitecture and vBMD were assessed using high-resolution peripheral quantitative computed tomography (HR-pQCT). Significant differences were observed between the analyzed age classes (i) young juveniles (0.5–10 months), (ii) yearlings (12–23 months), and (iii) adults (12–25 years) for several of the variables, indicating an overall increase in cortical and trabecular area, cortical thickness and total and cortical vBMD with age. Furthermore, for juvenile animals (≤ 23 months), significant positive correlations with age were observed for mandible length and perimeter, cortical area, cortical thickness, trabecular separation, and total and cortical vBMD. The findings demonstrate a rapid increase in overall size, cortical dimensions and the degree of mineralization of the harbor seal mandible during the first two years after birth. Negative correlations with age existed for trabecular number and thickness as well as for trabecular bone volume fraction in the juveniles. The findings suggest a reduction in trabecular bone volume fraction with age, due to the bone trabeculae becoming thinner, less numerous and more widely spaced. Given the strong age dependence of most analyzed parameters, it is recommended to standardize samples with respect to age in future studies comparing microarchitecture and mineralization of harbor seal mandibles from different populations or different collection periods.

Klíčová slova:

Bears – Bone density – Contaminants – Mandible – Marine mammals – Pollutants – Seals – Skull


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