108 



K.L. SANDERS ETAL. 



Fig. 1 Geographic origin of specimens used in multivariate analysis. S = Trimeresurus sumatranus; H = Trimeresurus hageni; U = unidentified 

 specimens. Shading represents the known distribution of T. hageni and/or T. sumatranus. 



Table 1 List of OTUs and sample size for each sex. 



OTU 



Sample Size 

 Males Females 



Thailand, West Malaysia, Singapore 



North Sumatra 1 (Medan) 



North Sumatra 2 (Medan) 



Central Sumatra 1 (Padang) 



Central Sumatra 2 (Padang) 



South Sumatra 1 (Palembang) 



Nias 



Siberut 



East Malaysia 



Betong (south Thailand) 



Total 



6 



15 



1 



1 







1 



1 



1 







1 







1 



1 



10 



3 



3 



4 



18 



1 







7 



51 



Museum Acronyms 



BMNH The Natural History Museum, London, formerly the 



British Museum (Natural History), London 

 FMNH Field Museum of Natural History, Chicago 

 IMR Institute of Medical Research, Kuala Lumpur 



KSP Sabah Park Zoological Museum, Mount Kinabalu 



National Park, Sabah 

 MCZ Museum of Comparative Zoology, Harvard 



MHNG Museum d'Histoire Naturelle de Geneva, Switzerland 

 NMBA Naturhistorisches Museum Basel, Switzerland 

 NMW Naturhistorisches Museum Vienna, Austria 

 QSMI Queen Saovabha Memorial Institute, Bangkok 

 PH Perhelitan, Kuala Lumpur 



ZRC Raffles Museum of Biodiversity Research, National 



University of Singapore, Singapore 



West Malaysia and Singapore and those normally assigned to T. 

 sumatranus from East Malaysia. The Siberut OTU and the single 

 specimens from Nias and northern Sumatra are closest to the main- 

 land T. hageni population. The specimens from Betong, Thailand 

 and central Sumatra are closest to the Borneo OTU, but are well 

 differentiated on CV2. 



Analysis of females also shows strong differentiation between the 

 Thailand, West Malaysia and Singapore OTU and the Borneo OTU. 

 The Siberut and Nias specimens are phenotypically close to T. 

 hageni from Thailand, West Malaysia and Singapore. Specimens 

 from north and south Sumatra are also closely affiliated to this 

 mainland population. The specimens from central Sumatra are 

 closest to the Borneo population along CV1, although are clearly 

 differentiated on CV2. 



CVA analysis can be used to identify the characters that account 

 for most variation between groups. In both sexes scalation characters 

 were more important in distinguishing between the taxa than were 

 characters relating to colour and pattern. The most important character 

 is the fifth supralabial scale, which meets the subocular scale in T. 

 sumatranus and in T. hageni is separated from the subocular by one 

 scale. Also important is the frequent presence of an internasal scale 

 in T. sumatranus, which is usually lacking in T. hageni. In addition, 

 T. sumatranus has fewer supralabial scales and fewer scales between 

 supraoculars than T. hageni. Our work verifies two of the original 

 diagnostic characters used by Lidth de Jeude (1886) who described 

 T. hageni as a distinct species that lacks dorsal cross-bands and has 

 fewer supralabial scales in contact with the subocular scale. How- 

 ever, we did not find dark edging on head and body scales to be a 

 valid diagnostic character on the basis that T. hageni specimens from 

 Nias have very strong dark edges on their head and body scales. 



RESULTS 



The CVA of males shows clear separation along the first canonical 

 variate of specimens normally assigned to T. hageni from Thailand, 



DISCUSSION 



The results of this preliminary analysis reveal a major phenotypic 



