Madhava Meegaskumbura | Guangxi University (original) (raw)

Papers by Madhava Meegaskumbura

FIGURE 3. Pseudophilautus semiruber: a, dorsal (whole body); b, profile; c, dorsal; d. ventral as... more FIGURE 3. Pseudophilautus semiruber: a, dorsal (whole body); b, profile; c, dorsal; d. ventral aspects, respectively, of head of female, WHT5831, 13.4 mm SVL. Scale bar: 1 mm.

FIGURE 2. Pseudophilautus semiruber (WHT5831), in life, Agra-Bopat Forest Reserve. A. profile; B.... more FIGURE 2. Pseudophilautus semiruber (WHT5831), in life, Agra-Bopat Forest Reserve. A. profile; B. dorsal aspect; C. fronto-dorsal aspect; D. ventral aspect.

FIGURE 1. Maximum likelihood tree of 12s and 16s rRNA gene fragments, with posterior probabilitie... more FIGURE 1. Maximum likelihood tree of 12s and 16s rRNA gene fragments, with posterior probabilities from the Bayesian analysis shown above and Maximum Parsimony Bootstrap values shown below the nodes respectively. Pseudophilautus semiruber (**) forms a clade with P. sim ba and P. cf. simba (*).

FIGURE 9. Labeo rohita, in preservation (WHT 30826, 124 mm SL).

FIGURE 8. Coloration of Labeo fisheri in preservation (UPZM uncatalogued, 258 mm SL, Sri Lanka, K... more FIGURE 8. Coloration of Labeo fisheri in preservation (UPZM uncatalogued, 258 mm SL, Sri Lanka, Kandy).

FIGURE 5. The TCS Haplotype network for Labeo heladiva (red) and L. dussumieri (green) population... more FIGURE 5. The TCS Haplotype network for Labeo heladiva (red) and L. dussumieri (green) populations based on the analysis of A, 666 bp fragment of the COI; and B, 1074bp fragment of the cytb genes. The sizes of the circles are proportional to the number of individuals sharing a given haplotype. The number of mutational steps are indicated by hatch marks. The black circles are hypothetical nodes.

Phylogenetic relationships among foam-nesting clades of Old World tree frogs are analyzed using b... more Phylogenetic relationships among foam-nesting clades of Old World tree frogs are analyzed using both nuclear and mitochondrial DNA data, with particular focus on Sri Lankan members of the genus Polypedates. A distinctive, highly supported endemic Sri Lankan clade is identified, and recognized as a new genus, Taruga. This clade, which had previously been assigned to the genus Polypedates, includes P. eques, P. fastigo and P. longinasus. A combination of characters distinguishes adult Taruga from Polypedates: Taruga possess a dorsolateral glandular fold that extends from the posterior margin of the upper eyelid to the mid-flank (vs. a supratympanic fold that curves over the dorsal margin of the tympanic membrane in Polypedates); a prominent calcar at the distal end of the tibia (absent in most Polypedates); a more acutely pointed snout; and 6–10 prominent conical tubercles surrounding the cloaca (absent in Polypedates). Tadpoles of Taruga eques and Polypedates cruciger are distinguish...

Ambio

As the two largest countries by population, China and India have pervasive effects on the ecosphe... more As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few coauthorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries' scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries' environmental performance, with implications for global sustainability.

REGIONAL OFFICE FOR ASIA AND THE PACIFIC TIGERPAPER is a quarterly news bulletin dedicated to the... more REGIONAL OFFICE FOR ASIA AND THE PACIFIC TIGERPAPER is a quarterly news bulletin dedicated to the exchange of information relating to wildlife and national parks management for the Asia-Pacific Region.

Two distinct nesting behaviours are reported from 98 clutches (80 in situ and 18 ex situ) of 17 s... more Two distinct nesting behaviours are reported from 98 clutches (80 in situ and 18 ex situ) of 17 species of direct-developing Philautus from Sri Lanka. The species examined, belong to three communities spanning 400-2,200 m elevation. Sixteen species are 'ground nesters', depositing 6-155 cream or white eggs in 5-35 mm deep nests excavated by the female in the rainforest floor. This is the first record of terrestrial egg burying in soil by the direct-developing anurans, a behaviour commonly employed by tetrapod reptiles. A single species (Philautus femoralis) however, is an arboreal nester, depositing 7-22 green, adhesive eggs in a disc-like mass on the underside of leaves. Parental care is not provided by any of the species. Larval development in Philautus differs from the Neotropical direct-developing leptodactylid, Eleutherodactylus coqui: the former lack external gills and have a rudimentary cement gland, a coiled gut and a larger, spatulate, heavily vascularized tail. The...

Aquatic tadpoles morphologically respond to presence of predators in various ways. Depending on t... more Aquatic tadpoles morphologically respond to presence of predators in various ways. Depending on the type of predator, tadpoles develop enhanced escape response abilities in accel- eration, maneuverability, and speed, and these are correlated to suites of morphological characters, such as wider, longer, and robust tail related dimensions. Laying eggs away from water, such as in an arboreal foam nest from which partially developed tadpoles fall into water, could be an adapta- tion for predator avoidance of eggs and early tadpole stages. Since predation is of concern, even for these partially developed larvae, we sought to detect predator-induced morphological response (if any) of these forms compared to fully aquatic tadpoles. We exposed the tadpoles of foam-nesting Polypedates cruciger to a natural fish predator, Belontia signata. We show that at an early (Gosner stage 29-32) stage, tadpoles exposed to this predator develop a larger body size and increased tail- length related dimens...

Two new species of Sri Lankan frogs of the genus Philautus are described. Species diagnoses are b... more Two new species of Sri Lankan frogs of the genus Philautus are described. Species diagnoses are based on morphology, morphometrics and mitochondrial DNA sequence data. Philautus tanu sp. nov. inhabits shrubs in open areas of the lowland wet zone, while P. singu sp. nov. is found on shrubs in the understory of lowland and mid-elevation rainforests. These descriptions bring the total number of valid Sri Lankan Philautus to 65 species, of which 46 are extant.

Ecology and Evolution

Ranaviral infections, a malady of ectothermic vertebrates, are becoming frequent, severe, and wid... more Ranaviral infections, a malady of ectothermic vertebrates, are becoming frequent, severe, and widespread, causing mortality among both native and cultured species, raising odds of species extinctions and economic losses. This turn of events is possibly due to the broad host range of ranaviruses and the transmission of these pathogens through regional and international trade in Asia, where outbreaks have been increasingly reported over the past decade. Here we focus attention on the origins, means of transmission, and patterns of spread of this infection within the region. Infections have been recorded in both cultured and wild populations in at least twelve countries/administrative regions, together with mass die-offs in some regions. Despite the imminent seriousness of the disease in Asia, surveillance efforts are still incipient. Some of the infections transmitted within Asia may transmit across host-taxon barriers, posing a significant risk to native species. Factors such as rising temperatures due to global climate change seem to exacerbate ranaviral activity, as most known outbreaks have been recorded during summer; however, data are still inadequate to verify this for Asia. Import risk analysis, using protocols such as Pandora+, pre-border pathogen screening, and effective biosecurity measures, can be used to mitigate introduction to uninfected areas and curb transmission within Asia. Comprehensive surveillance using molecular diagnostic tools for ranavirus species and variants will help in understanding the prevalence and disease burden in the region. This is an important step towards conserving native biodiversity and safeguarding the aquaculture industry.

Biological Journal of the Linnean Society

Despite exhibiting multiple morphological adaptations to living in swiftly flowing water (rheophi... more Despite exhibiting multiple morphological adaptations to living in swiftly flowing water (rheophily), Garra ceylonensis is one of the most widely distributed freshwater fish in Sri Lanka. It is thus an ideal organism to reconstruct the evolutionary history of a widespread, yet morphologically specialized, freshwater fish in a tropical-island setting. We analysed the phylogenetic and phylogeographic relationships of G. ceylonensis based on two mitochondrial and one nuclear genes. G. ceylonensis is shown to be monophyletic, with a sister-group relationship to the Indian species Garra mullya. Our results suggest a single colonization of Sri Lanka by ancestral Garra, in the late Pliocene. This suggests that the Palk Isthmus, which was exposed for most of the Pleistocene, had a hydroclimate unsuited to the dispersal of fishes such as Garra. G. ceylonensis exhibits strong phylogeographic structure: six subclades are distributed as genetically distinct populations in clusters of contiguous...

Although large diversifications of species occur unevenly across space and evolutionary lineages,... more Although large diversifications of species occur unevenly across space and evolutionary lineages, the relative importance of their driving mechanisms, such as climate, ecological opportunity and key innovations, 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. Montane regions on islands and some mainland regions have higher phylogenetic diversity and unique assemblages of taxa; we identify these as cool-wet refugia. Starting from a centre of origin, rhacophorids reached these distant refugia by adapting to new climatic conditions (‘niche evolution’-dominant), especially following the origin of key...

Systematics and Biodiversity

The freshwater-fish genus Laubuka contains ∼13 species distributed through the lowlands of tropic... more The freshwater-fish genus Laubuka contains ∼13 species distributed through the lowlands of tropical South and South-east Asia. Four of these species (Laubuka lankensis, L. varuna, L. ruhuna, and L. insularis) are reported as endemic to Sri Lanka, a remarkable datum given the island’s small size. We sampled populations of Laubuka at 56 locations in 14 of the island’s principal river basins and analysed their morphological, meristic, phylogenetic, and phylogeographic relationships using the mitochondrial genes cytochrome b and cytochrome c oxidase subunit 1 and the nuclear recombination activating protein 1. We investigated the geographic structure, and delineated species using molecular species delimitation methods and morphological analysis within the general lineage concept of species. Molecular and morphological analyses failed to identify L. ruhuna and L. insularis as distinct species; we show them to be synonyms of L. varuna and L. lankensis, respectively. Taxonomic inflation in previous literature is attributed as a result of limited sampling and negligence of size allometry. Additionally, a third, cryptic species discovered in this study is described as L. hema sp. nov. which is evidently confined to the headwaters of the Gal basin in eastern Sri Lanka. Phylogenetic and haplotype network analyses suggest phylogeographic structure within both the southwest-endemic L. varuna and the dry-zone endemic L. lankensis, but the former shows strong phylogeographic structure between adjacent basins. The Sri Lankan species of Laubuka do not form a monophyletic group: they stem from two dispersal or vicariance events, one involving the lineage that led to L. varuna in south-western Sri Lanka, and the other, of [L. lankensis + L. hema] in the dry zone. http://zoobank.org/urn:lsid:zoobank.org:pub:D2A29329-E0E7-447E-B316-81049212CCCB http://zoobank.org/urn:lsid:zoobank.org:act:920E5DC0-CEDC-4243-98C7-12CCF829CBCD

Zoologica Scripta

The South and South‐East Asian freshwater fish genus Systomus (Cyprinidae) comprises 17 valid spe... more The South and South‐East Asian freshwater fish genus Systomus (Cyprinidae) comprises 17 valid species. Six nominal species, including three endemics, have been reported from Sri Lanka, a continental island separated from India by a shallow‐shelf sea. The species diversity of Systomus on the island has until now not been assessed; neither has an evaluation been made of their phylogenetic history. Here, based on an analysis of the nuclear recombination activating protein 1 (rag1), and mitochondrial cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) gene markers, and a morphological examination of 143 specimens from 49 locations in Sri Lanka, we reassess the diversity of Systomus on the island and analyse patterns of their evolution and biogeography. Divergence‐time estimates, based on a substitution rate calibration, date the basal split between Systomus and its sister group, the Afrotropical small barbs, to 30.0 Ma (95% highest posterior density: 25.4–35.2 Ma). The species of Systomus belong to two distinct clades. The first includes the Sri Lankan endemics S. asoka, S. martenstyni and S. pleurotaenia, which comprise an insular diversification following the immigration of a common ancestor during the Oligocene. The second, which includes the remaining species of Indian, Sri Lankan and South‐East Asian Systomus, has a crown age dating to the Late Miocene. Morphological and molecular species delimitation analyses failed to validate the two nominal species, S. spilurus and S. timbiri, previously reported from Sri Lanka: both are considered synonyms of S. sarana, as are the nomina S. chryseus, S. chrysopoma, S. laticeps, S. rufus, S. pinnauratus and S. subnasutus. Four genetically and geographically discrete lineages of S. sarana occur in the island, and three in India. Molecular species delimitation analysis suggests these all belong to a single species, S. sarana. The genetically distinct Sri Lankan populations of S. sarana result from Plio‐Pleistocene dispersal or vicariance events between India and Sri Lanka—as a result of emergence and inundation of the now submerged isthmus connecting the two landmasses—as well as autochthonous insular diversification.