Breeding biology of the endemic Dull-blue Flycatcher Eumyias sordidus in Sri Lanka

captureAuthors: Chathuranga Dharmarathne and Dharshani Mahaulpatha

Journal: Forktail 

he breeding biology of the endemic Dull-blue Flycatcher Eumyias sordidus was studied in the tropical montane cloud forests of Horton Plains National Park, Sri Lanka, from March 2016 to December 2018. Breeding ran from late March until June, and again from late August to October. Nestling diet was studied using a spotting scope, video camera and faecal sample analysis. A total of 68 nests were found and 32 breeding pairs were observed. The average incubation period was 20.1 ± 2.2 days and nestling period was 14 ± 3.1 days. During incubation, nest attentiveness was higher in the evening. Pairs were double-brooded and some pairs made re-nesting attempts after first nests failed. Coleoptera were their major food source, followed by Araneae and Hymenoptera. The overall nest success was 90.6% (29 out of 32 nests). Jungle Crow Corvus levaillantii was the main predator.

New analysis sinks eight shrub frogs but finds 14 putative new species

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Authors: Gajaba Ellepola, Jayampathi Herath, Kelum Manamendra-Arachchi, Nayana Wijayathilaka, Gayani Senavirathne, Rohan Pethiyagoda and Madhava Meegaskumbura.

Journal: Plosone

Sri 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. With species described primarily by morphological means, the diversification has never yet been subjected to a molecular species delimitation analysis, a procedure now routinely applied in taxonomy. Here we test the species boundaries of Pseudophilautus in the context of the phylogenetic species concept (PSC). We use all the putative species for which credible molecular data are available (nDNA–Rag-1; mt-DNA– 12S rRNA, 16S rRNA) to build a well resolved phylogeny, which is subjected to species delimitation analyses. The ABGD, bPTP, mPTP and bGMYC species delimitation methods applied to the 16S rRNA frog barcoding gene (for all species), 12S rRNA and Rag-1 nDNA grouped P. procax and P. abundus; P. hallidayi and P. fergusonianus; P. reticulatus and P. pappilosus; P. pleurotaenia and P. hoipolloi; P. hoffmani and P. asankai; P. silvaticus and P. limbus; P. dilmah and P. hankeni; P. fulvus and P. silus.. Surprisingly, all analyses recovered 14 unidentified potential new species as well. The geophylogeny affirms a distribution across the island’s aseasonal ‘wet zone’ and its three principal hill ranges, suggestive of allopatric speciation playing a dominant role, especially between mountain masses. Among the species that are merged by the delimitation analyses, a pattern leading towards a model of parapatric speciation emerges ongoing speciation in the presence of gene flow. This delimitation analysis reinforces thespecies hypotheses, paving the way to a reasonable understanding of Sri Lankan Pseudophilautus, enabling both deeper analyses and conservation efforts of this remarkable diversification.

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Modified, optimized method of determination of Tributyltin (TBT) contamination in coastal water, sediment and biota in Sri Lanka

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Authors: K.R.V. Bandara, S.D.M. Chinthaka, S.G. Yasawardene and Pathmalal M. Manage

Journal: Marine Pollution Bulletin

Tributyltin (TBT) is a toxic organotin compound that belongs to the group of Persistent Organic Pollutants (POPs) and it is documented to cause severe sexual disorders development in aquatic fauna. According to the present study, The TBT concentration in coastal water ranged from 303 ± 7.4 ngL− 1 to 25 ± 4.2 ngL− 1 wherein sediment was from 107 ± 4.1 ngKg− 1 to 17 ± 1.4 ngKg− 1 . TBT in Perna viridis was found to range from 4 ± 1.2 ngKg− 1 to 42 ± 2.2 ngKg− 1 wet weight and in ascending order of the body weight. The highest TBT level in water and sediment was found in the Colombo port where the highest level of TBT in P. viridis (42 ± 2.2 ngKg− 1 ) was recorded from the Dikkowita fishery harbor. A positive correlation between the number of male P. viridis and TBT level (p < 0.05) suggests possible reproductive impairment in aquatic animals exposed continuously to a high concentration of TBT.

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Isolation and Identification of Cellulase Producing and Sugar Fermenting Bacteria for Second-Generation Bioethanol Production

 

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Authors: L.I. Weerasinghe, Tharindu Madusanka and Pathmalal M. Manage

Journal: International Journal of Renewable Energy Development

Over the last decades, the negative impacts of fossil fuel on the environment and increasing demand for energy due to the unavoidable depletion of fossil fuels, has transformed the world’s interests towards alternative fuels. In particular, bioethanol production from cellulosic biomass for the transportation sector has been incrementing since the last decade. The bacterial pathway for bioethanol production is a relatively novel concept and the present study focused on the isolation of potential “cellulase-producing” bacteria from cow dung, compost soil, and termite gut and isolating sugar fermenting bacteria from palm wine. To select potential candidates for cellulase enzyme production, primary and secondary assays were conducted using the Gram’s iodine stain in Carboxy Methyl Cellulose (CMC) medium and the Dinitrosalicylic acid (DNS) assays, respectively. Durham tube assay and Solid-Phase Micro-Extraction (SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) was used to evaluate the sugar fermenting efficiency of the isolated bacteria. Out of 48 bacterial isolates, 27 showed cellulase activity where Nocardiopsis sp. (S-6) demonstrated the highest extracellular crude enzyme activity of endoglucanase (1.56±0.021 U) and total cellulase activity (0.93±0.012 U). The second-highest extracellular crude enzyme activity of endoglucanase (0.21±0.021 U) and total cellulase activity (0.35±0.021 U) was recorded by Bacillus sp. (T-4). Out of a total of 8 bacterial isolates, Achromobacter sp. (PW-7) was positive for sugar fermentation resulting in 3.07% of ethanol in broth medium at 48 h incubation. The results of the study revealed that Nocardiopsis sp. (S-6) had the highest cellulase enzyme activity. However, the highest ethanol percentage was achieved with by having both Bacillus sp. (T-4) and Achromobacter sp. (PW-7) for the simultaneous saccharification and fermentation (SSF) method, as compared to separate hydrolysis and fermentation (SHF) methodologies