Frogs of the genus include some of the world's smallest amphibians and represent the largest radiation of Asian microhylids, currently encompassing 50 species, distributed across the Oriental biogeographic region. The genus remains one of the taxonomically most challenging groups of Asian frogs and was found to be paraphyletic with respect to large-sized fossorial . In this study we present a time-calibrated phylogeny for frogs in the genus , and discuss taxonomy, historical biogeography, and morphological evolution of these frogs.
View Article and Find Full Text PDFThe Ceylon krait () is a highly venomous elapid snake endemic to Sri Lanka. Its bites are rare and only seven reports are found in the literature. Therefore, the clinical manifestations and natural history of envenoming of Ceylon krait are not well studied yet.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2020
Unlike other snakes, most species of possess glands in their dorsal skin, sometimes limited to the neck, known as nucho-dorsal and nuchal glands, respectively. Those glands contain powerful cardiotonic steroids known as bufadienolides, which can be deployed as a defense against predators. Bufadienolides otherwise occur only in toads (Bufonidae) and some fireflies (Lampyrinae), which are known or believed to synthesize the toxins.
View Article and Find Full Text PDFA new species of Cnemaspis Strauch, 1887 is described from Nilgala Savannah Forest in Sri Lanka. The new species is diagnosed from all other congeners by the following suite of characters: small body size (SVL< 33 mm), dorsal scales on trunk homogeneous, one pair of post mentals separated by a single small chin scale, ventral scales on trunk smooth, subimbricate, 17-19 scales across the belly. Subdigitals scansors smooth, entire, unnotched; lamellae under digit IV of pes 17 -18.
View Article and Find Full Text PDFA large body of evidence indicates that evolutionary innovations of novel organs have facilitated the subsequent diversification of species. Investigation of the evolutionary history of such organs should provide important clues for understanding the basis for species diversification. An Asian natricine snake, , possesses a series of unusual organs, called nuchal glands, which contain cardiotonic steroid toxins known as bufadienolides.
View Article and Find Full Text PDFAmong the eight species of Eutropis Fitzinger currently known from Sri Lanka, Eutropis bibronii (Gray, 1838) is among the least known. Hence, the occurrence of this species in Sri Lanka has been doubted by some authors since there were no confirmed records from live specimens for the past 70 years. The species has been previously reported mostly from northern regions of Sri Lanka.
View Article and Find Full Text PDFGonatodes kandianus var. tropidogaster was described by Boulenger (1885) with only "Ceylon" (=Sri Lanka) as its locality. This taxon was later assigned to the genus Cnemaspis and then recorded from many different parts of the country.
View Article and Find Full Text PDFThe first study on ticks on reptiles of Sri Lanka dates back to Seneviratna (1965) who reported ticks from five reptiles. Later studies were either limited to one reptile (Fernando & Fernando 2012), or captive animals in zoos (Fernando & Randeniaya 2009) and household pets (Nathanael et al. 2004).
View Article and Find Full Text PDFThe viviparous sea snakes (Hydrophiinae) are a young radiation of at least 62 species that display spectacular morphological diversity and high levels of local sympatry. To shed light on the mechanisms underlying sea snake diversification, we investigated recent speciation and eco-morphological differentiation in a clade of four nominal species with overlapping ranges in Southeast Asia and Australia. Analyses of morphology and stomach contents identified the presence of two distinct ecomorphs: a 'macrocephalic' ecomorph that reaches >2 m in length, has a large head and feeds on crevice-dwelling eels and gobies; and a 'microcephalic' ecomorph that rarely exceeds 1 m in length, has a small head and narrow fore-body and hunts snake eels in burrows.
View Article and Find Full Text PDFWe present a striking case of phenotypic convergence within the speciose and taxonomically unstable Hydrophis group of viviparous sea snakes. Enhydrina schistosa, the 'beaked sea snake', is abundant in coastal and inshore habitats throughout the Asian and Australian regions, where it is responsible for the large majority of recorded deaths and injuries from sea snake bites. Analyses of five independent mitochondrial and nuclear loci for populations spanning Australia, Indonesia and Sri Lanka indicate that this 'species' actually consists of two distinct lineages in Asia and Australia that are not closest relatives.
View Article and Find Full Text PDFMol Phylogenet Evol
October 2010
Hemidactylus geckos are a species-rich component of many tropical lizard assemblages. We sampled deeply among tropical Asian, and especially South Asian, taxa and used a multi-gene approach to establish the affinities of Indian and Sri Lankan Hemidactylus and to evaluate the monophyly of previously proposed taxa within the genus. There is only weak support for the monophyly of tropical Asian Hemidactylus as a whole, but two strongly supported subclades were retrieved: the bowringii group is a predominantly East Asian clade that reaches South Asia only peripherally; the brookii group is a morphologically diverse clade that represents a previously unrecognized, species-rich (25 species), chiefly South Asian radiation.
View Article and Find Full Text PDFThe rice frog (Fejervarya limnocharis) species complex is widely distributed, from India to Japan, and most prevalently in Southeast Asia. Conspicuous morphological variation has been reported for this species complex throughout its distribution range. In the present study, we used mtDNA gene sequence and allozyme analyses to infer evolutionary affinities within this species complex using eight populations (Sri Lanka; Bangkok and Ranong in Thailand; Taiwan; and Hiroshima, Okinawa, Ishigaki and Iriomote in Japan).
View Article and Find Full Text PDFIn order to elucidate the genetic relationships and reproductive-isolation mechanisms among the Fejervarya limnocharis complex from Indonesia and other Asian countries, allozyme analyses and crossing experiments were carried out using 208 individuals from 21 localities in eight Asian countries. The allozyme analyses revealed that 17 enzymes examined were controlled by genes at 27 loci, and that 7.9 phenotypes were produced by 5.
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