Hoi Sen YongPhaik Eem LimJi TanPraphathip EamsobhanaUniversity of MalayaMahidol University2018-10-192018-10-192013-02-28Raffles Bulletin of Zoology. Vol.61, No.1 (2013), 47-51021724452-s2.0-84874755081https://repository.li.mahidol.ac.th/handle/123456789/31065Although genetically determined colour polymorphism is quite common in adult odonates, there is no report on this phenomenon in the larvae of any odonate species up to now. This paper reports, for the first time, the occurrence of two colour morphs (dark and brown) in both the male and female larvae of the damselfly Ceriagrion chaoi Schmidt. The species identity of these colour morphs was confirmed by the partial sequences of 16S rRNA gene as well as observation on emergence. Only a single invariant haplotype was observed, which differed from a congeneric species Ceriagrion cerinorubellum (Brauer) by 39 base pairs. The partial sequences of 16S rRNA gene constitute the first report for these damselflies. Available data indicate that environment/habitat does not seem to play a role in the determination of the colouration in the larvae of C. chaoi. The inheritance and significance of the colour polymorphism however remain to be verified. © National University of Singapore.Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS