Age determination of South African fur seals (Arctocephalus pusillus pusillus)

Abstract

Known-age teeth were used to validate age determination techniques. Upper canines were the most suitable for age estimation. Dentine growth layer groups (GLGs) reflected age accurately in canines and cementum GLGs in post canines, but not with the same accuracy, and should be used only where the pulp cavities of canines are closed. Ground sectioning is highly recommended because accurate age estimates were obtained for all teeth, both from dentine GLGs in canines and cementum GLGs in post canines. Thin sectioning and staining of decalcified teeth produced the poorest age estimates. For etched half canines, only upper canines could be used to estimate age with good results, where coating improved the accuracy. Scanning electron microscopy produced poor accuracy in age estimation. External ridges reflected age accurately only in younger age classes and should only be used to verify counts of internal GLGs, or where rapid, preliminary estimates of age are necessary.