Successful age estimation in dugong

24 March 2021

Faculty of Veterinary Medicine

Age estimation in dugongs from the telomere length by using molecular biology technique is another successful collaboration between the Faculty of Veterinary Medicine, Chiang Mai University and Phuket Marine Biological Centre.

Faculty of Veterinary Medicine, CMU, in collaboration with Phuket Marine Biological Centre, Department of Marine and Coastal Resources, Ministry of Natural Resources and Environment, was successful at estimating dugong’s age by measuring the telomere length in cells by using a molecular biology technique. This novel approach to age estimation provides advantages over the existing technique measuring the light bands in the front tooth that has many limitations.

Dugong is a marine mammal whose population has significantly decreased. In Thailand, there are only about 200, mostly found in the Trang area. Being endangered, It is protected by several laws, including The Fisheries Act, B.E. 2490 (1947), National Park Act B.E. 2490 (1947), Wildlife Conservation and Protection Act, B.E. 2535 (1992) and The Convention on International Trade in Endangered Species of Wild Fauna and Flora. Conservation of this mammal is difficult because it cannot be bred and its survivability in a confined space is low, as can be seen from the cases of baby dugongs, ‘Mariam’ or ‘Yamil’.

Assoc.Prof.Dr. Korakot Nganvongpanit, the head researcher from the Faculty of Veterinary Medicine, explains that using molecular biology technique to measure the length of telomere, which is the end of a chromosome. There have been studies on several animals, including human, and the results vary. It was effective in some but not the others, with several limitations and details. However, this study was able to come up with an equation to predict dugong’s age at 86% accuracy, which is extremely high. Moreover, the fact that dugong becomes fully mature at the age of 20 is a novel discovery and the findings have been validated, as the research has already been published in an international journal. What is gained from this study is the age data of dugongs, with or without the tusks, and this technique can be applied to estimating the age of living dugongs as well.

Dr. Kongkiat Kittiwatanawong, Director of Phuket Marine Biological Centre, adds that estimating dugong’s age had always been difficult, as the old technique in counting the light bands in dugong’s tusk or snout is extremely limiting because the snouts are usually stolen before the officials get to the bodies. Moreover, this technique does not work if the snout is damaged and nor does it work for living dugongs. That is the reason why the benefit of this study is tremendous because analysis of extracted DNAs would provide estimated age. Even if it is not 100% accurate, its benefit is large enough for other agencies to employ.