[Testudology • 2008] Diversity of the Southeast Asian Leaf Turtle genus Cyclemys: How many leaves on its tree of life?

Fig. 9 A–E. Ventral aspects of hatchlings of Cyclemys spp.
(A) Cyclemys atripons (Chanthaburi, Thailand; paratype); (B) C. dentata (Palawan, Philippines); (C) C. pulchristriata (Phuc Son, central Vietnam; holotype); (D) C. enigmatica (western Nias, Indonesia; paratype); (E) C. oldhamii (Thailand).

Not to scale. Juvenile pattern (radiating lines along scute seams) already developing in USNM 94745. Hatchlings of C. fusca and C. gemeli unknown. — Photos: F. Höhler.

Abstract

In the present study, we use mtDNA sequence data (cyt b gene) in combination with nuclear DNA sequences (C-mos, Rag2 genes, R35 intron), nuclear genomic fingerprints (ISSR) and morphological data to reveal species diversity within the Southeast Asian leaf turtle genus Cyclemys, a morphologically difficult group comprising cryptic species. Two morphologically distinct major groupings exist, a yellow-bellied species group with three taxa (Cyclemys atripons, C. dentata, C. pulchristriata) and a dark-bellied species group. The latter contains besides the morphologically variable C. oldhamii three additional new species (C. enigmatica n. sp., C. fusca n. sp., C. gemeli n. sp.). According to mtDNA data, C. fusca and C. gemeli constitute with high support the sister group of a clade comprising all other species, indicating that the dark-bellied species are not monophyletic, despite morphological similarity. mtDNA sequences of C. enigmatica, being highly distinct in nuclear genomic markers, do not differ from the sympatric C. dentata, suggesting that the original mitochondrial genome of C. enigmatica was lost due to introgressive hybridization. Morphological discrimination of Cyclemys species is possible using multivariate methods. However, gross morphology of most dark-bellied species on the one hand and of C. atripons and C. pulchristriata on the other is so similar that reliable species determination is only possible when genetic markers are used. The high diversity within Cyclemys requires revision of the IUCN Red List Categories for leaf turtles because the former assessment was based on the wrong assumption that in the entire range of the genus occurs only a single species.

Fig. 10 Range of the genus Cyclemys (shaded) and genetically verified records of
 (1) C. atripons, (2) C. dentata, (3) C. pulchristriata, (4) C. enigmatica,
(5) C. fusca, (6) C. gemeli, (7) C. oldhamii and (8) putative C. fusca × C. oldhamii hybrid.
For C. dentata and C. enigmatica genetically not verified records are also shown (grey symbols).

Fig. 9 A–E. Ventral aspects of hatchlings of Cyclemys spp.
(A) Cyclemys atripons (USNM 94745, Khao Sabap, Chanthaburi, Thailand; paratype);
(B) C. dentata (ZMUC E56, Palawan, Philippines); (C) C. pulchristriata (Phuc Son, central Vietnam; holotype); (D) C. enigmatica (ZMA 19029:2, western Nias, Indonesia; paratype); (E) C. oldhamii (SMNS 5355:1, Thailand).

Not to scale. Juvenile pattern (radiating lines along scute seams) already developing in USNM 94745. Hatchlings of C. fusca and C. gemeli unknown. — Photos: F. Höhler.

Fritz, U.; D Guicking, M Auer, R. S Sommer, M Wink, A. K Hundsdörfer. 2008. Diversity of the Southeast Asian Leaf Turtle genus Cyclemys: How many leaves on its tree of life? Zoologica Scripta. 37(4), 367–390. doi:  10.1111/j.1463-6409.2008.00332.x. 

http://www.iucn-tftsg.org/wp-content/uploads/file/Articles/Fritz_etal_2008a.pdf

Louise Durkin, Markus Handschuh, Keo Sovannak, Lizzy Ward, Nikki Hulse and Alistair Mould. 2010. Discovery of a hitherto unknown breeding population of the Asian leaf turtle Cyclemys aff. atripons in Phnom Kulen National Park, northwestern Cambodia.Cambodian Journal of Natural History. 2010 (1) 15-17
http://www.accb-cambodia.org/en/Discovery%20of%20Cyclemys%20in%20PKNP_ACCB%20-%20Durkin%20et%20al.pdf