11 research outputs found
Cryptic diversity of limestone karst inhabiting land snails (Cyclophorus spp.) in northern Vietnam, their evolutionary history and the description of four new species
Limestone karsts can form terrestrial habitat islands for calcium-dependent organisms. In Vietnam, many karst habitats are threatened, while their rich biodiversity is still far from being thoroughly explored. Given that conservation of karst biota strongly relies on correct species identification, the presence of undetected cryptic species can pose severe problems. The present study focuses on cryptic diversity among karst-inhabiting land snails of the genus Cyclophorus in northern Vietnam, where specimens with a similar shell morphology have been reported from various regions. In order to examine the diversity and evolutionary history of this “widespread morphotype”, we generated a Bayesian phylogeny based on DNA sequence data. Automatic Barcode Gap Discovery (ABGD) and the Bayesian implementation of the Poisson tree processes model (bPTP) contributed to species delimitation and analyses of shell shape and size aided the morphological characterisation of individual species. We found that the examined specimens of the widespread morphotype did not form a single monophyletic group in the phylogeny but clustered into several different clades. We delimited nine different species that develop the widespread morphotype and described four of them as new. Processes of convergent evolution were probably involved in the origin of the delimited species, while their generally allopatric distribution could result from interspecific competition. Our findings indicate ongoing processes of speciation and a potential case of morphological character displacement. The high degree of morphological overlap found among the species underlines the importance of DNA sequence data for species delimitation and description in the genus Cyclophorus. Given the findings of the present study and the high potential that as yet undiscovered cryptic taxa have also evolved in other groups of karst-inhabiting organisms, we argue for a systematic and efficient detection and description of Vietnam’s karst biodiversity to provide a solid basis for future conservation planning.Copyright: © 2019 von Oheimb et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Exploring the shell-based taxonomy of the Sri Lankan land snail Corilla H. and A. Adams, 1855 (Pulmonata: Corillidae) using mitochondrial DNA
The land-snail genus Corilla is endemic to Sri Lanka and India’s Western Ghats. The ten extant Sri Lankan species belong to two distinct shell forms that are associated respectively with lowland and montane rainforest. We here present the first molecular phylogenetic analysis for Corilla. Our dataset includes nine nominal Sri Lankan species and is based on three mitochondrial genes (CO1, ND1 and 16S). Although the deeper nodes in the trees are not fully resolved, the results do suggest speciation in Corilla has involved repeated, ecologically-driven convergence in shell form. The mtDNA data agree with the current shell-based taxonomy for C. adamsi, C. beddomeae, C. carabinata, C. humberti and C. colletti, consistently supporting the first four as monophyletic, and supporting the last also as monophyletic in nearly all analyses. Corilla adamsi, C. beddomeae and C. colletti may each contain at least one additional, previously undescribed species. The relationship between northern and eastern C. odontophora couldn’t be reliably resolved, but our results suggest that they are distinct species and that there is further species-level or intraspecific (geographical) differentiation within eastern C. odontophora. The current, morphologically-defined species limits of the three remaining nominal species, C. gudei, C. erronea and C. fryae, are inconsistent with the mtDNA sequence data. Northern and southern C. gudei appear to be distinct species: the sister taxon of southern C. gudei is C. humberti, and most analyses showed that the sister taxon of northern C. gudei is the lowland C. carabinata. Corilla erronea and C. fryae constitute a well supported clade in which both nominal species are paraphyletic. While most intra-clade CO1 p-distances are moderate to relatively large, the phylogenetic structuring within the clade does not seem to correspond to any obvious morphological, elevational or geographical patterns. These results are difficult to interpret, and further detailed study is needed before the taxonomic status of C. erronea and C. fryae can be resolved
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Genetic variation in the Giant African Snail Lissachatina fulica (Bowdich, 1822) in its invasive ranges of Asia and West Africa
The rapidly spreading Giant African Snail Lissachatina [=Achatina] fulica (Bowdich, 1822) has been introduced to many parts of the world since the 1800s and is one of the world’s most invasive species. We compared cytochrome oxidase subunit I (COI) sequences from four invasive ranges: India, United Arab Emirates (UAE), China and West Africa. Sixteen distinct haplotypes were identified, with nine found in India, four in the UAE, one in China and four in West Africa. Haplotype 5 was the most common haplotype in Asia and haplotype 1 the most common in West Africa. Network analysis suggests that all haplotypes in India, the UAE, China and West Africa were derived from the most common haplotype 5 which is present in all three invasive ranges in Asia. Higher levels of genetic variation were observed in the invasive ranges of Asia than in West Africa. The high genetic variation observed in Asia, together with high levels of trade as exemplified by wood import data, supports the hypothesis that there could have been multiple invasion events in India and the UAE. Additional sampling from the native and invasive ranges in Africa and from other regions of invasion is essential for understanding the movement and spread of L. fulica
Fine-scale geographical sampling and molecular characterization of the giant African land snail in its invasive range in Asia shows low genetic diversity, new haplotypes and the emergence of another haplotype from the Indian Ocean Islands
Native to East Africa, the giant African snail Lissachatina [=Achatina] fulica (Bowdich, 1822) is a tropical crop pest and one of the world’s top 100 invasive species. It is now present in at least 52 countries worldwide, with an actively expanding range. Lissachatina fulica was first introduced to India in 1847, but subsequent arrivals in India and local patterns of spread remain unclear. This study uses the 16S rRNA gene to identify the extent of genetic variation in India by sampling Indian populations and comparing them with published sequence data. A total of 307 snails were collected from 178 localities in India and from a single locality in the UAE, and the 16S rRNA gene was amplified and sequenced. Eight haplotypes were identified from India of which four are newly recognized. The new haplotypes identified in this study have increased the number of L. fulica 16S rRNA haplotypes from 19 to 23. Examination of haplotype and nucleotide diversities revealed that genetic variation is low in India, the UAE and across Asia as a whole. The number of haplotypes was higher in India when compared to other invasive regions but all of the Asian haplotypes appear to be closely related to the most common haplotypes in the Indian Ocean Islands. Heavy trade between the snail-infested and native-range countries suggests that the variation observed in India might be traced back to its native range, but the lack of sampling and paucity of sequences from East Africa currently prevents a comparison. Tracing back the emergent haplotypes by additional sampling could throw more light on the spread of L. fulica
Competition matters: Determining the drivers of land snail community assembly among limestone karst areas in northern Vietnam
The insular limestone karsts of northern Vietnam harbor a very rich biodiversity. Many taxa are strongly associated with these environments, and individual species communities can differ considerably among karst areas. The exact processes that have shaped the biotic composition of these habitats, however, remain largely unknown. In this study, the role of two major processes for the assembly of snail communities on limestone karsts was investigated, interspecific competition and filtering of taxa due to geographical factors. Communities of operculate land snails of the genus Cyclophorus were studied using the dry and fluid‐preserved specimen collections of the Natural History Museum, London. Phylogenetic distances (based on a Bayesian analysis using DNA sequence data) and shell characters (based on 200 semilandmarks) were used as proxies for ecological similarity and were analyzed to reveal patterns of overdispersion (indicating competition) or clustering (indicating filtering) in observed communities compared to random communities. Among the seven studied karst areas, a total of 15 Cyclophorus lineages were found. Unique communities were present in each area. The analyses revealed phylogenetic overdispersion in six and morphological overdispersion in four of seven karst areas. The pattern of frequent phylogenetic overdispersion indicated that competition among lineages is the major process shaping the Cyclophorus communities studied. The Coastal Area, which was phylogenetically overdispersed, showed a clear morphological clustering, which could have been caused by similar ecological adaptations among taxa in this environment. Only the community in the Cuc Phuong Area showed a pattern of phylogenetic clustering, which was partly caused by an absence of a certain, phylogenetically very distinct group in this region. Filtering due to geographical factors could have been involved here. This study shows how museum collections can be used to examine community assembly and contributes to the understanding of the processes that have shaped karst communities in Vietnam.© 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Land snails from archaeological sites in the Marshall Islands, with remarks on prehistoric translocations in tropical oceania
We report the recovery of 11 taxa of nonmarine mollusks from archaeological sites on Majuro, Maloelap, and Ebon Atolls, Republic of the Marshall Islands. Pupina complanata (Pupinidae), Omphalotropis fragilis (Assimineidae), Truncatella guerinii (Truncatellidae), Lamellidea pusilla and Pacificella variabilis (Achatinellidae), Gastrocopta pediculus (Gastrocoptidae), Nesopupa sp. (Vertiginidae), "Succinea" sp. (Succineidae), Allopeas gracile (Subulinidae), and Liardetia samoensis (Helicarionidae) arrived in these islands prehistorically; Liardetia sculpta (Helicarionidae) has not yet been recovered from levels of confirmed prehistoric age. Pupina complanata, O. fragilis, and probably also Nesopupa sp., and "Succinea" sp. are Micronesian endemics. Al other species are widely distributed in Micronesia and Polynesia and (except for the strand-line species T. guerinii) were undoubtedly translocated to the Marshall Islands by the prehistoric voyages of Pacific islanders. The precise role of human transport in the dispersal of the Micronesian endemics remains unclear, but because these atolls have been emergent for a mere 3,000 yr or so, human transport is likely in view of the known rarity of natural interarchipelagic dispersal of nonmarine mollusks