Publications by authors named "Anslem de Silva"

Article Synopsis
  • - Systematic assessments of species extinction risk are crucial for effective conservation, and the second Global Amphibian Assessment evaluated over 8,000 species for their threat levels.
  • - Amphibians are the most at-risk vertebrates, with 40.7% of species globally threatened, and their status has worsened since previous assessments, especially in salamanders and the Neotropics.
  • - The major threats contributing to declining amphibian populations include disease, habitat loss, and increasing impacts from climate change, highlighting the urgent need for more conservation funding and initiatives to reverse negative trends.
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Article Synopsis
  • A comprehensive assessment of reptile extinction risks reveals that 21.1% of reptile species, or 1,829 out of 10,196, are threatened, highlighting the urgent need for conservation strategies amidst global extinction crises.
  • Similar to other tetrapods like amphibians, mammals, and birds, reptiles face threats from agriculture, logging, urban development, and invasive species, with forest-dwelling reptiles being at a higher risk than those in arid environments.
  • Although some reptile species need immediate action for conservation, broader efforts targeting other tetrapods, such as habitat protection and managing invasive species, could also benefit many reptile species.
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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.

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The 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.

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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.

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A 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.

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A 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.

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Among 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.

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Gonatodes 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.

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The 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).

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The 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.

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We 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.

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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.

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The 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).

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In 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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