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Taxonomy and Systematics using Multiple Criteria - General Lineage Concept, Integrative Taxonomy

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Pradeep Samarawickrama
added a research item
In September 2019, the IUCN/CI Biodiversity Assessment Unit held a workshop to complete IUCN Red List assessments for 169 species of snakes and lizards of the 230 currently (September 2019) described reptile species known from Sri Lanka, as part of the Global Reptile Assessment. Additionally, a preliminary Key Biodiversity Area (KBA) assessment was conducted and the IUCN SSC Conservation Planning Specialist Group facilitated the Assess to Plan (A2P) process to identify the next steps towards conservation action for all species assessed as threatened. Of the 169 species assessed during the workshop, 102 (60%) were categorised as threatened (Critically Endangered, Endangered or Vulnerable), with 100 (98%) of these being endemic to Sri Lanka. Additionally, 17 species (10%) were assessed as Data Deficient, all of which are Sri Lankan endemics.
Madhava Meegaskumbura
added 2 research items
Ixalus semiruber Annandale, a diminutive (12-mm snout-vent length) frog originally described from the highlands of Sri Lanka in 1913, has not been recorded in the succeeding century and is treated as Data Deficient for conservation purposes. Here we report its rediscovery in Agra-Bopath, a sub-montane forest reserve. Pseudophilautus semiruber is distinguished by a combination of the following characters: size 12.0–13.4 mm SVL; canthal edges rounded; tympanum distinct; vomerine ridge absent; supratympanic fold feebly defined; throat, chest, belly and underside of thigh smooth. It is a high-elevation (1,750 m a.s.l.) diurnal species that inhabits heavily-shaded leaf litter.
This study presents a systematic revision of South Asian members of the taxonomically challenging genus Microhyla Tschudi, 1838. Species relationships and diagnostic characters are determined by integrating molecular, morphological, and acoustic approaches, through which we also recognize six groups of closely related species. In addition, a new species from the southern Western Ghats of India is formally described as Microhyla darreli sp. nov. Species accounts of all the 16 recognized members from South Asia include current taxonomic status, metric and meristic characters, divergence in mitochondrial DNA, phylogenetic relationships, acoustic characters, revised geographical distributions, and natural history notes. Molecular and morphological relationships of three poorly known members — M. chakrapanii, M. karunaratnei, and M. zeylanica — are clarified for the first time since their original descriptions. The presence of M. berdmorei and another potential new species close to M. heymonsi in India is genetically confirmed, and several misidentifications are corrected. For comparative purposes, molecular, morphological, and acoustic relationships are also discussed for eight closely related East and Southeast Asian species. Consequently, insights from this study will facilitate a much-needed comprehensive revision of the Pan-Asian frog genus Microhyla.
Pradeep Samarawickrama
added a research item
A new species of the genus Cophotis from Sri Lanka is described. Summary of phylogenetic studies of the position of the genus Cophotis within Draconinae subfamily is provided. Distribution of both species of the genus Cophotis in Sri Lanka is shown.
Madhava Meegaskumbura
added 15 research items
Eight new species of Sri Lankan frogs of the genus Philautus are described (P. mooreorum, P. poppiae, P. hoffmanni, P. mittermeieri, P. frankenbergi, P. hallidayi, P. steineri and P. stuarti). The species are diagnosed on the basis of mitochondrial DNA sequence, morphological features and, in two cases, bioacoustics data. Six of the eight species are confined to high elevation cloud forest isolates on the three main mountain ranges of central Sri Lanka. Because of their limited geographic distribution and small extent of remaining habitat, these species are classified as Endangered under the IUCN Red List criteria. These descriptions bring the total number of Sri Lankan Philautus to 61 species, 44 of which are extant.
A new species of crocidurine shrew, Crocidura hikmiya, is described from the Sinharaja World Heritage Site, Sri Lanka. The species is diagnosed on the basis of both morphology and mitochondrial DNA sequence data. Morphologically C. hikmiya is distinguished from C. miya, among other characters, by having a shorter tail, condyles protruding beyond the margin of the braincase, a posterior edge of maxillary bone rounded (dorsal view), an occipital bone triangularly shaped with an obtuse angle (dorsal view) and slightly flattened on the back; a foramen magnum less deep (ventral view); a dor-sal posterior brain case not smooth; and an angular process of dentary short and stout. Phylogenetic analysis suggests that C. hikmiya is the sister-species of C. miya. The uncorrected genetic distance between the two species for the mitochon-drial cytochrome-b gene fragment is 9.7–10.1%, suggesting species-level divergence. Crocidura hikmiya is confined to the mid-montane forests and lowland rainforests in the southwestern Sri Lanka, while C. miya is confined to montane forests of the central hills.
The species hitherto included in the genus Chela are shown to belong to two distinct genera, Chela (type species C. cachius) and Laubuca (type species L. laubuca). The Indian and Sri Lankan species of Laubuca (L. laubuca, L. fasdata, L. dadyburjori, L. lankensis and three new species, L. insularis, L. ruhuna and L. varuna) are distinguished from C. cachius, the type species of Chela (among other characters) by having 14 pre-caudal vertebrae (vs. 17 in C. cachius); 31-37 + 1-2 lateral-line scales (vs. 56-61 + 3-4); 7-11 scales in transverse line on body (vs. 17-19); and 14-20 branched anal-fin rays (vs. 21-23). Within Sri Lanka, the dry-zone species L. lankensis and L. insularis are distinguished from their wet-zone congeners L. varuna and L. ruhuna by having the skin over the dentary densely tuberculated (vs. tubercles minute, widely spaced). Laubuca lankensis is distinguished from L. insularis by its shorter pelvic fins (not reaching anal-fin origin, vs. reaching beyond base of third branched anal-fin ray in L. insularis); while L. ruhuna is distinguished from L. varuna by its deeper body (2.9-3.1 in SL, vs. 3.2-3.6 in L. varuna).