Morphological characteristics and mitochondrial COI gene of the green water dragon in Phu Quoc island, Vietnam


  • Van Thong Ngo*
  • Huu Hanh Tran Kien Giang Vocational College
  • Chi Tao Phan


The green water dragons of Phu Quoc island, Vietnam have been given a VU rating (vulnerable) by the Vietnam red data book and the International Union for conservation of nature and natural resources. A description of the morphological characteristics and sequenced mitochondrial cytochrome oxidase subunit 1 COI gene was completed following a survey of thirty individuals from September 2018 to May 2019. Their body weights ranged from 115 to 850 g and their snout-vent length ranged from 120 to 280 mm. They were identified to have the highest similarity to the species Physignathus cocincinus by the barcode of life data system. Their COI gene sequence was compared to GenBank (KM272197.1) and the following alternations were found: C5483T, A5486C, C5537A, A5564G, A5591G, T5633C, G5684A, A5771G, A5849C, C5927T, T5942C, C5993T, G6002A, and A6020G. The neighbourjoining tree of their COI sequence divergence indicated a distance (compared to the same published species) from 2.3 to 2.8%. Thus, it might be possible that the green water dragons of Phu Quoc island are evolving into a specific subspecies. However, more green water dragon specimens from Phu Quoc should be sequenced to ensure a conclusion and further research into farming should be initiated to protect this vulnerable species


COI, gene sequence, morphology, Phu Quoc, Physignathus cocincinus


Classification number


Author Biographies

Van Thong Ngo

Faculty of Agriculture and Rural Development, Kien Giang University, 320A Highway 61, Vinh Hoa Hiep, Chau Thanh City, Kien Giang Province, Vietnam

Huu Hanh Tran, Kien Giang Vocational College

Kien Giang Vocational College, 1022 Nguyen Trung Truc, An Hoa Ward, Rach Gia City, Kien Giang Province, Vietnam

Chi Tao Phan

Veterinary Station of Long My District, Hau Giang Province, Vietnam




Received 29 December 2020; revised 20 January 2021; accepted 25 March 2021

How to Cite

Van Thong Ngo, Huu Hanh Tran, & Chi Tao Phan. (2021). Morphological characteristics and mitochondrial COI gene of the green water dragon in Phu Quoc island, Vietnam. Vietnam Journal of Science, Technology and Engineering, 63(3), 63-69.



Life Sciences