Origin, diversity, and conservation of karst-associated Bent-toed Geckos (Genus Cyrtodactylus) in Myanmar (Burma)

Abstract

Fifty-eight percent of the 43 known species of the Bent-toed Geckos (Cyrtodactylus) from Myanmar are found only in karstic habitats in the Shan Plateau and Salween and Ayeyarwady basins. A stochastic character mapping analysis indicated that the occupation of karstic habitats evolved at least four times independently in Burmese lineages with both Sundaic and Indian origins. Karstic habitats not only serve as foci for speciation but are refugia for species extirpated from the surrounding forested habitats due to agricultural development. Despite the high levels of biodiversity and site-specific endemism in karstic habitats in Myanmar, they are some of the least protected ecosystems. The immense financial returns from unsustainable resource extraction (cement manufacturing) makes the challenge of legal karst conservation extremely difficult. Sadly, their continued exploitation for limestone shows no signs of abating. Until karst habitats in Myanmar are thoroughly investigated, a significant portion of this country’s herpetological diversity will remain underestimated and unprotected.

Evolution of habitat preference in 243 species of Bent‐toed geckos (GenusCyrtodactylusGray, 1827) with a discussion of karst habitat conservation

“…In the last decade, the remarkable increase in the discovery of new species in the ecologically and morphologically diverse gekkonid genus Cyrtodactylus Gray, 1827 (see Grismer et al., 2020a) makes it a promising model to study the evolution of adaptive shifts in their habitat preference. Cyrtodactylus currently contains 296 nominal species (as of 10 July 2020; Uetz et al., 2020) that collectively range from South Asia to Melanesia (Figure 1).…”

Sex Chromosome Turnover in Bent-Toed Geckos (Cyrtodactylus)

“…Because the vast majority of Cyrtodactylus species have yet to be studied ( Figure 3 A) there is almost certainly additional sex chromosome diversity within the genus. Cyrtodactylus is the most speciose gecko genus and continues to grow as new species are described every year [ 55 , 56 ]. However, less than 1% of species have a known sex determination system.…”

Gekkota Mundi – the world of geckos

“…Thus, global warming bodes ill for their probability of future survival because the competing lowland species will be able to shift their distributions upwards, potentially displacing the mountain endemics (Oliver et al 2020). In the seventh paper Grismer et al (2020b) discusses the Burmese species of the incredibly diverse genus Cyrtodactylus (305 species, the second-largest reptile genus, 71 of which were described by Lee Grismer and his group; Uetz 2020; this volume). They find that most (58%) of the Cyrtodactylus in Myanmar are karst-habitat endemics, and that the association with karst independently evolved at least for times in this group.…”

“…They find that most (58%) of the Cyrtodactylus in Myanmar are karst-habitat endemics, and that the association with karst independently evolved at least for times in this group. They point out that many karst habitats in Myanmar and elsewhere in SE Asia remain to be surveyed -thus large numbers of undescribed Cyrtodactylus species are likely to occur in this region (Grismer et al 2020b). Grismer et al (2020b) further note that karst habitats are under increasing pressure from mining and are not protected by current legislation.…”

“…They point out that many karst habitats in Myanmar and elsewhere in SE Asia remain to be surveyed -thus large numbers of undescribed Cyrtodactylus species are likely to occur in this region (Grismer et al 2020b). Grismer et al (2020b) further note that karst habitats are under increasing pressure from mining and are not protected by current legislation. The karst-dwelling species are therefore often at great peril.…”