A frog adaptive radiation: Ecomorphological evolution in Old-World shrub frogs (Rhacophoridae:Pseudophilautus)

Madhava Meegaskumbura; Gajaba Ellepola; Gayani Senevirathne; Kelum Manamendra-Arachchi; Nayana Wijayathillaka; Marcio Pie; Dan Sun; Rohan Pethiyagoda; Christopher J. Schneider

published in bioRxiv

Ecomorphs result from divergent natural selection, leading to species-rich adaptive radiations. Identifying ecomorphs and the resulting adaptive radiations in frogs is challenging due to conserved morphology and high species diversity. In this study, we demonstrate the ecological and climate specializations that have driven the diversification of shrub frogs of the genus Pseudophilautus in Sri Lanka, a tropical continental island. We use a time-calibrated phylogeny, morphometric analyses, and climate-niche evolution, and identify five ecomorphological categories, including Tree-shrub, Rock-boulder, Leaf-litter, Habitat Generalists, and Canopy forms, and describe their evolution. Body size is the primary factor separating species, and specific body features correlate with habitat type. Ecomorphs likely evolved multiple times in disparate lineages, and in different regions and altitudes, during cold climatic periods owing to monsoon cycles resulting from the Himalayan-Tibetan orogeny. The common ancestor was a medium-sized, wet-adapted, tree-shrub habitat specialist which originated in the late Oligocene. Extreme size classes (diminutive leaf litter forms and large canopy forms) evolved recently and suggest that morphological disparity arose late in diversification, possibly aided by favorable climates. This work will facilitate understanding of adaptive radiations in frogs, which possibly will help uncover the prevalence of subtle adaptive radiations in frogs, just as in tailed-vertebrates.

Waste Biomass Valorization and Its Application in the Environment

A. K. C. Wijerathna, K. P. P. Udayagee, F. S. Idroos & Pathmalal M. Manage

Book chapter published in Sustainable Valorization of Agriculture & Food Waste Biomass

There has been a significant increase in global waste generation owing to rapid urbanization and industrialization. Anthropogenic activities associated with exploiting natural resources pose severe threats to the long-term resilience of ecosystems. The buildup of waste biomass in ecosystems causes various adverse environmental conditions, such as greenhouse gas emissions, global warming, bioaccumulation and biomagnification of hazardous chemicals, surface and groundwater pollution, and acid rains suppress and lessen biological diversity. According to the World Bank predictions, 3.4 billion tons of municipal solid waste will have been generated by 2050. Thus, effective waste biomass management through valorization is critical in circular bio-economy and meeting environmental feasibility. Due to its abundance and renewability, lignocellulosic waste biomass can be a beneficial substrate to produce many high-value goods such as biofuels, biofertilizers, composts, biochar, pharmaceuticals, bioplastics, and food additives. This chapter summarizes the potential of hydrothermal conversion processes, including hydrothermal carbonization, hydrothermal liquefaction, and hydrothermal gasification, in producing a range of value-added products from solid waste substances. Moreover, the future trends of biological conversions that use microbial bioconversion generate a number of eco-friendly valorized products like biopesticides, biohydrogen, organic acids, antibiotics, enzymes, food colors, amino acids, and single-cell proteins were discussed. Further, this chapter highlights the multidisciplinary approaches for waste biomass valorization combined with advanced bio-nanotechnology, enzymatic sequent biomass hydrolysis treatments that are becoming popular and research gaps to overcome the challenges of waste biomass valorization by enhancing the process efficiency.

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Use of the Allium cepa Model to Assess the Cytogenotoxicity of Luffariella herdmani Marine Sponge Extract

Sashini U. Kuruppuarachchi, Uthpala A. Jayawardena and Varuni K. Gunathilake

published in Alternatives to Laboratory Animals

Marine sponge extracts are known to contain potentially toxic compounds that have biological activities of possible pharmacological interest. Thus, it is vital that biological models are used for the preliminary toxicity screening of such extracts. The present study reports the use of Allium cepa, a low-cost plant-based in vivo model, to assess the cytotoxicity and genotoxicity of Luffariella herdmani marine sponge crude extract (SCE). Pre-germinated onion bulbs, exposed for 96 hours to different concentrations of SCE (ranging from 0.3125 to 20 μg/ml), were used to determine general cytotoxicity. Root length as well as morphological abnormalities were recorded. Genotoxicity was assessed by exposing the root tips to SCE (0.3125–20 μg/ml) and the appropriate controls for 48 hours, and then staining with acetocarmine. The
Mitotic Index (MI), Mitotic Phase Indices (MPIs) and chromosomal aberrations were evaluated and recorded. SCE inhibited A. cepa root growth (EC50 = 10.34 μg/ml) and elicited a mitodepressive effect (LC50 = 1.95 μg/ml) in a dose-dependent and significant manner. In addition, macroscopic alterations as well as chromosomal aberrations were detected. Overall, our findings indicate that L. herdmani crude extract exhibits cytotoxic and genotoxic activity, suggesting that it might contain substances with anti-proliferative/anticancer potential that could be subject to further characterisation.

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Taxonomic status of Pseudophilautus conniffae (Anura: Rhacophoridae) an endemic shrub frog restricted to South–Western wet zone of Sri Lanka

SHASHIKA ABEYSEKARA; HELANI SAMARASINGHE; KELUM MANAMENDRA-ARACHCHI; HIMASH ADHIKARI; SONALI PREMARATHNE; CHAMPIKA BANDARA; USHANI PERERA; NAYANA WIJAYATHILAKA

published in Zootaxa

Pseudophilautus conniffae from Lowland wet zone of Sri Lanka, was described as a new species in 2019. The validity of the new species was questionable and was often challenged as it shares strong morphological resemblance with P. limbus. Moreover, the phylogenetic placement of P. conniffae was unknown as no molecular data was available until now. Here, we generated 16S DNA sequences and re-examined the external morphological characters to assess its taxonomic distinctiveness. Pseudophilautus conniffae was recovered as being close to P. limbus with strong posterior probability and bootstrap support. The uncorrected pairwise genetic distance between P. conniffae and P. limbus was negligible, being less than 0.3% for the 16S gene fragment. Further two molecular species delimitation methods, ABGD and mPTP suggested that P. conniffae and P. limbus are a single operational taxonomic unit. The Principal Component Analysis of the morphometric characters also resulted in overlapping clusters. These results suggest that the newly described P. conniffae is not a valid species and we conclude that P. conniffae as a junior synonym of P. limbus.