ABSTRACT

Figure 1

The Southeast Asian country of Myanmar (formerly Burma) has five currently recognized species of geckos within the genus Hemidactylus. Hemidactylus are united by derived traits in toe morphology of the manus and pes, with sizeable variation among species in other traits. These variations make Hemidactylus a systematically difficult group. A recent molecular study shows genetic divergences within the tropical Asian clade, consisting of two monophyletic groups (Carranza & Arnold, 2006). The purpose of this project was to conduct a systematic study of one Burmese species, H. bowringii, to determine if morphological differentiation has occurred alongside the genetic divergences. Mensural and meristic characters were adapted from Zug et. al., 2003. Data were collected from samples from throughout Myanmar and Yunnan, China and analyzed using Systat 11. Results show significant (P<0.05) differences between the two H. bowringii clades. Additionally, morphological differentiation occurs throughout other regions in Myanmar, with potentially more divergences within this species than represented in the phylogeny.

INTRODUCTION

Five currently recognized species of Hemidactylus geckos occur in Myanmar (Figure 1). Among the most speciose of the gekkonids (~80 known sp.) some have only recently been described (Baha el Din, 2003, 2005; Henle & Böhme, 2003). Species are united by derived traits in toe morphology, including varying degrees of divisions in a number of toe lamellae of the manus and pes. However, sizeable variation exists among species in traits such as head proportions, body and limb size, degree of division in toe lamellae, and scalation patterns. In a recent molecular analysis (Carranza & Arnold, 2006), fragments of two mitochondrial genes from 30 species of Hemidactylus show genetic divergences within the tropical Asian clade; consisting of two monophyletic groups (Figure 2). We conducted a systematic study of one species in Myanmar, H. bowringii (Figure 3), to determine if morphological differentiation has occurred alongside the genetic divergences.

Hemidactylus molecular phylogeny tropical Asian clade (Carranza & Arnold, 2006)

MATERIALS & METHODS

• Specimens obtained by the CAS-NWCD-SI Myanmar Herpetological Survey and the CAS-China Yunnan Biodiversity Survey. The total sample consisted of 90 specimens partitioned into 8 locality samples throughout Myanmar and Yunnan, China.
• Set of 12 mensural and 13 meristic (scalation) character traits selected. Traits adapted from Zug et. al. (2003). Each specimen dissected to examine gonads to determine sex and maturity.
• SYSAT version 11 was used for all statistical analyses.
  
  

RESULTS

• While difficult to systematically standardize, there is potential differentiation in scale markings between various localities (Fig. 4a). Note the bilateral spots in 1-4b and the broken bar pattern in 2-4b.
• There are apparent differences in body size among adults between populations from various localities (Fig. 4b). Yunnan adults (top row) mean SVL 49.19+3.46mm; Shwe Settaw adults (bottom row) mean SVL 37.52+1.71mm.
• No characters were found to be sexually dimorphic within this species in Myanmar.

Figure 4a

Figure 4b

DISCUSSION

There is only a marginally significant difference between individuals from our Kachin samples and the Shan/Yunnan clade. All three are at relatively similar elevations. Individuals from the Yangon clade are morphologically very different from Yunnan/Shan and Kachin populations. These data support the H. bowringii divergences proposed by Carranza & Arnold. However, only those three localities were sampled for the phylogeny. Our data also show significant (P<0.05) morphological differences between populations in other regions of Myanmar, suggesting there are potentially more divergences within Burmese H. bowringii than proposed by the Carranza & Arnold phylogeny.

ACKNOWLEDGEMENTS

Nature & Wildlife Conservation District of Forestry Division in Myanmar
California Academy of Sciences (Jens V. Vindum)
SI-NMNH Biodiversity & Survey Program
NSF (DEB-9971861, DEB-0451832)
NMNH Division of Amphibians & Reptiles
SI-NMNH Research Training Program Office of the Director

REFERENCES

Baha el Din, S.M., 2003. A new species of Hemidactyus (Squamata: Gekkonidae) from Egypt. African Journal of Herpetology. 52, 39-47.

Baha el Din, S.M., 2005. An overview of Egyptian species of Hemidactylus (Gekkonidae) with the description of a new species from the high mountains of South Sinai. Zool. Mid. East. 34, 11-26.

Carranza, S, and E.N. Arnold. 2006. Systematics, biogeography, and evolution of Hemidactylus geckos (Reptilia: Gekkonidae) elucidated using mitochondrial DNA sequences. Molecular Phylogenetics and Evolution 38:531-545.

Henle, K., and W. Böhme. 2003. A new species of Hemidactylus (Squamata: Gekkonidae) from West Africa, and comments on species hitherto confused with H. muriceus. African Journal of Herpetology. 52, 23-38.

Zug, George R., Dick Watling, Tataua Alefaio, Semese Alefaio, and Claudia Ludescher. 2003. A new gecko (Reptilia: Squamata: Genus Lepidodactylus) from Tuvalu, South-central Pacific. Proceedings of the Biological Society of Washington 116(1):38-46.

Hemidactylus bowringii
Magway Division, Myanmar