Sri Lanka's biota is derived largely from Southeast Asian lineages which immigrated via India following its early-Eocene contact with Laurasia. The island is now separated from southeastern India by the 30 km wide Palk Strait which, during sea-level low-stands, was bridged by the 140 km-wide Palk Isthmus. Consequently, biotic ingress and egress were mediated largely by the climate of the isthmus.
View Article and Find Full Text PDFRicefishes of the genus occur commonly in the fresh and brackish waters in coastal lowlands ranging from India across Southeast Asia and on to Japan. Among the three species of recorded from peninsular India, two widespread species, and , have previously been reported from Sri Lanka based on museum specimens derived from a few scattered localities. However, members of the genus are widespread in the coastal lowlands of Sri Lanka, a continental island separated from India by the shallow Palk Strait.
View Article and Find Full Text PDFLarge diversifications of species are known to occur unevenly across space and evolutionary lineages, but the relative importance of their driving mechanisms, such as climate, ecological opportunity and key evolutionary innovations (KEI), remains poorly understood. Here, we explore the remarkable diversification of rhacophorid frogs, which represent six percent of global amphibian diversity, utilize four distinct reproductive modes, and span a climatically variable area across mainland Asia, associated continental islands, and Africa. Using a complete species-level phylogeny, we find near-constant diversification rates but a highly uneven distribution of species richness.
View Article and Find Full Text PDFBackground: Sri Lanka is a continental island separated from India by the Palk Strait, a shallow-shelf sea, which was emergent during periods of lowered sea level. Its biodiversity is concentrated in its perhumid south-western 'wet zone'. The island's freshwater fishes are dominated by the Cyprinidae, characterized by small diversifications of species derived from dispersals from India.
View Article and Find Full Text PDFSri Lanka is an amphibian hotspot of global significance. Its anuran fauna is dominated by the shrub frogs of the genus Pseudophilautus. Except for one small clade of four species in Peninsular India, these cool-wet adapted frogs, numbering some 59 extant species, are distributed mainly across the montane and lowland rain forests of the island.
View Article and Find Full Text PDFThe small, colourful freshwater fishes of the cyprinid genus Devario are among the many vertebrate groups that appear to have diversified on Sri Lanka, a continental Indian Ocean island, which is part of the Western Ghats-Sri Lanka Biodiversity Hotspot. Despite Sri Lanka having been connected with India via a wide isthmus intermittently until the Plio-Pleistocene and almost continuously since then, during sea-level low-stands, the number of species of Devario on Sri Lanka is comparable with that on the Indian Peninsula, some 25 times its size. Here, from a sampling of 27 Devario populations across Sri Lanka's major river basins and climatic zones, we present and analyze a phylogeny based on mitochondrial and nuclear DNA data.
View Article and Find Full Text PDFMorphological and molecular analyses of specimens representative of the geographic range of the cyprinid genus in Sri Lanka suggest the presence of only a single species in the island, for which the name Jordan & Starks, 1917, is available. is a species endemic to Sri Lanka, distributed across the lowlands of both of the island's main climatic zones. It is distinguished from all other species of , including the three species recorded from peninsular India (, , and ), by a suite of characters that includes a body depth of 26.
View Article and Find Full Text PDFWe address several problems arising from 'A review of the genus Devario in Sri Lanka (Teleostei: Cyprinidae), with description of two new species', a paper authored by S. Batuwita, M. de Silva and S.
View Article and Find Full Text PDFA recent (2013) taxonomic review of the freshwater-fish genus , which is endemic to Sri Lanka, showed it to comprise four species: , , and Here, using an integrative-taxonomic analysis of morphometry, meristics and mitochondrial DNA sequences of () and (), we show that is a synonym of , and that is a synonym of The creation and recognition of unnecessary taxa ('taxonomic inflation') was in this case a result of selective sampling confounded by a disregard of allometry. The population referred to in the Walawe river basin represents an undocumented trans-basin translocation of , and a translocation into the Mahaweli river of , documented to have occurred 1980, in fact involves A shared haplotype suggests the latter introduction was likely made from the Bentara river basin and not from the Kelani, as claimed. To stabilize the taxonomy of these fishes, the two valid species, and , are diagnosed and redescribed, and their distributions delineated.
View Article and Find Full Text PDFPseudophilautus comprises an endemic diversification predominantly associated with the wet tropical regions of Sri Lanka that provides an opportunity to examine the effects of geography and historical climate change on diversification. Using a time-calibrated multi-gene phylogeny, we analyze the tempo of diversification in the context of past climate and geography to identify historical drivers of current patterns of diversity and distribution. Molecular dating suggests that the diversification was seeded by migration across a land-bridge connection from India during a period of climatic cooling and drying, the Oi-1 glacial maximum around the Eocene-Oligocene boundary.
View Article and Find Full Text PDFSnakehead fishes of the family Channidae are predatory freshwater teleosts from Africa and Asia comprising 38 valid species. Snakeheads are important food fishes (aquaculture, live food trade) and have been introduced widely with several species becoming highly invasive. A channid barcode library was recently assembled by Serrao and co-workers to better detect and identify potential and established invasive snakehead species outside their native range.
View Article and Find Full Text PDFThe PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.
View Article and Find Full Text PDFThe bufonid genus Adenomus, an endemic of the montane and lowland rainforests of central and south-western Sri Lanka, has been considered to comprise of three species, viz. A. kelaartii, A.
View Article and Find Full Text PDFThe South Asian Cichlidae are composed of two clades that together represent the sister group of the Madagascan genus Paretroplus Bleeker. Chaetodon suratensis Bloch and Etroplus canarensis Day are retained in Etroplus Cuvier, while Chaetodon maculatus Bloch is allocated to Pseudetroplus Bleeker. Pseudetroplus is distinguished from Etroplus in having, among other characters, 11 (vs.
View Article and Find Full Text PDFAs part of a Global Biodiversity Hotspot, the conservation of Sri Lanka's endemic biodiversity warrants special attention. With 51 species (50 of them endemic) occurring in the island, the biodiversity of freshwater crabs is unusually high for such a small area (65,600 km(2)). Freshwater crabs have successfully colonized most moist habitats and all climatic and elevational zones in Sri Lanka.
View Article and Find Full Text PDFThe apparent biotic affinities between the mainland and the island in the Western Ghats-Sri Lanka biodiversity hotspot have been interpreted as the result of frequent migrations during recent periods of low sea level. We show, using molecular phylogenies of two invertebrate and four vertebrate groups, that biotic interchange between these areas has been much more limited than hitherto assumed. Despite several extended periods of land connection during the past 500,000 years, Sri Lanka has maintained a fauna that is largely distinct from that of the Indian mainland.
View Article and Find Full Text PDFThe first phylogenetic hypothesis for the Sri Lankan agamid lizard genus Ceratophora is presented based on 1670 aligned base positions (472 parsimony informative) of mitochondrial DNA sequences, representing coding regions for eight tRNAs, ND2, and portions of ND1 and COI. Phylogenetic analysis reveals multiple origins and possibly losses of rostral horns in the evolutionary history of Ceratophora. Our data suggest a middle Miocene origin of Ceratophora with the most recent branching of recognized species occurring at the Pliocene/Pleistocene boundary.
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