Displaying publications 1 - 20 of 32 in total

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  1. Lum JY, Chiu MC, Tseng SP, Scotty Yang CC, Lee CY
    J Econ Entomol, 2023 Apr 24;116(2):520-528.
    PMID: 36715608 DOI: 10.1093/jee/toad010
    The longlegged ant Anoplolepis gracilipes (Smith) is a highly invasive tramp ant species known for its deleterious effects on native ecosystems. While tramp ants are associated with human activity, information on how different intensities of human activity affect their distribution is limited. This study investigated how anthropogenic activities affected the distribution of A. gracilipes in Penang, a tropical island in northern peninsular Malaysia. Three study sites (Youth Park, Sungai Ara, and Bukit Jambul/Relau) were selected, containing four sub-locations corresponding to different levels of human activity (low, moderate, high, and very high), determined by the average number of passersby observed over 30 min. Baited index cards were placed at each sub-location to evaluate ant abundance and distribution. The results demonstrated that A. gracilipes worker abundance was highest in areas of moderate human activity, as opposed to areas with low and higher human activity. The low abundance of A. gracilipes in comparatively undisturbed localities may be attributed to unsuitable microclimate, lack of propagule pressure, and diminished honeydew availability. In contrast, its exclusion from more urbanized localities could be explained by high interspecific competition with other tramp species and the absence of preferred nesting sites.
    Matched MeSH terms: Introduced Species
  2. Nguyen DTC, Tran TV, Nguyen TTT, Nguyen DH, Alhassan M, Lee T
    Sci Total Environ, 2023 Jan 20;857(Pt 2):159278.
    PMID: 36216068 DOI: 10.1016/j.scitotenv.2022.159278
    Above 1000 invasive species have been growing and developing ubiquitously on Earth. With extremely vigorous adaptability, strong reproduction, and spreading powers, invasive species have posed an alarming threat to indigenous plants, water quality, soil, as well as biodiversity. It was estimated that an economic loss of billions of dollars or equivalent to 1 % of gross domestic product as a consequence of lost crops, control efforts, and damage costs caused by invasive plants in the United States. While eradicating invasive plants from the ecosystems is practically infeasible, taking advantage of invasive plants as a sustainable, locally available, and zero-cost source to provide valuable phytochemicals for bionanoparticles fabrication is worth considering. Here, we review the harms, benefits, and role of invasive species as important botanical sources to extract natural compounds such as piceatannol, resveratrol, and quadrangularin-A, flavonoids, and triterpenoids, which are linked tightly to the formation and application of bionanoparticles. As expected, the invasive plant-mediated bionanoparticles have exhibited outstanding antibacterial, antifungal, anticancer, and antioxidant activities. The mechanism of biomedical activities of the invasive plant-mediated bionanoparticles was insightfully addressed and discussed. We also expect that this review not only contributes to efforts to combat invasive plant species but also opens new frontiers of bionanoparticles in the biomedical applications, therapeutic treatment, and smart agriculture.
    Matched MeSH terms: Introduced Species*
  3. Rane R, Walsh TK, Lenancker P, Gock A, Dao TH, Nguyen VL, et al.
    Sci Rep, 2023 Jan 12;13(1):660.
    PMID: 36635481 DOI: 10.1038/s41598-023-27501-x
    The fall armyworm (FAW) Spodoptera frugiperda is thought to have undergone a rapid 'west-to-east' spread since 2016 when it was first identified in western Africa. Between 2018 and 2020, it was recorded from South Asia (SA), Southeast Asia (SEA), East Asia (EA), and Pacific/Australia (PA). Population genomic analyses enabled the understanding of pathways, population sources, and gene flow in this notorious agricultural pest species. Using neutral single nucleotide polymorphic (SNP) DNA markers, we detected genome introgression that suggested most populations in this study were overwhelmingly C- and R-strain hybrids (n = 252/262). SNP and mitochondrial DNA markers identified multiple introductions that were most parsimoniously explained by anthropogenic-assisted spread, i.e., associated with international trade of live/fresh plants and plant products, and involved 'bridgehead populations' in countries to enable successful pest establishment in neighbouring countries. Distinct population genomic signatures between Myanmar and China do not support the 'African origin spread' nor the 'Myanmar source population to China' hypotheses. Significant genetic differentiation between populations from different Australian states supported multiple pathways involving distinct SEA populations. Our study identified Asia as a biosecurity hotspot and a FAW genetic melting pot, and demonstrated the use of genome analysis to disentangle preventable human-assisted pest introductions from unpreventable natural pest spread.
    Matched MeSH terms: Introduced Species
  4. Yek SH, Sethu Pathy T, Yeo DYC, Gan JYS
    PeerJ, 2023;11:e16157.
    PMID: 37868047 DOI: 10.7717/peerj.16157
    Anthropogenic disturbances and seasonal changes significantly impact diversity and community composition of ants, but their effects are often intertwined. We investigated these drivers on Lang Tengah Island, a location with a pronounced monsoon season and three resorts that close during this period. We surveyed four sites, two disturbed and two undisturbed, before and after the monsoon season, using pitfall traps to sample epigaeic ant communities. Undisturbed habitats had higher species diversity, but both habitats (undisturbed and disturbed sites) have a high proportion of ants with characteristics of being encroached by generalist and invasive/tramp ant species. Post-monsoon sampling yielded an increase in species richness and diversity. Seasonal changes, such as monsoonal rains, can temporarily alter ant interactions and resource distribution, potentially maintaining diversity. Future studies should validate these findings for ant communities under similar pressures, using ant composition and functional roles for conservation and management purposes.
    Matched MeSH terms: Introduced Species
  5. Vilizzi L, Copp GH, Hill JE, Adamovich B, Aislabie L, Akin D, et al.
    Sci Total Environ, 2021 Sep 20;788:147868.
    PMID: 34134389 DOI: 10.1016/j.scitotenv.2021.147868
    The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a 'very high risk' of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate 'rapid' management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement.
    Matched MeSH terms: Introduced Species*
  6. Juergens J, Bruslund S, Staerk J, Oegelund Nielsen R, Shepherd CR, Leupen B, et al.
    Data Brief, 2021 Jun;36:107093.
    PMID: 34041313 DOI: 10.1016/j.dib.2021.107093
    In this article we present a standardized dataset on 6659 songbirds (Passeriformes) highlighting information relevant to species conservation prioritization with a main focus to support the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Data were collected from both scientific and grey literature as well as several online databases. The data are structured into six knowledge categories: Conventions and Treaties, Human Use, Extinction Risk, Management Opportunities, Biological Information, and Intrinsic Values. The Conventions and Treaties category includes the listings for two international conventions, CITES and the Convention on the Conservation of Migratory Species of Wild Animals (CMS), as well as EU listings for the EU Wildlife Trade Regulations and the EU Birds Directive. The Human Use category contains information on both regulated trade collected from the CITES Trade Database and the United States' Law Enforcement Management Information System (LEMIS), and highly aggregated data on seizures which we obtained from TRAFFIC, the United Nations Office on Drugs and Crime (UNODC) and two data sources on traditional medicine. We also present, for the first time, the complete Songbirds in Trade Database (SiTDB), a trade database curated by taxon expert S. Bruslund based on expert knowledge, literature review, market surveys and sale announcements. Data on the types of human use, including traditional medicine are also provided. The knowledge area on Extinction Risk contains data on the species' IUCN Red List status, the Alliance for Zero Extinction Trigger Species status, site and population at the site, the species' IUCN Climate Change Vulnerability Assessment, and the listing of priority species at the Asian Songbird Crisis Summit. In the Management Opportunities category, we gathered data on ex-situ management from Species360 zoo holdings as well as species management plans from the European and North American Zoo Associations (EAZA and AZA, respectively). Biological Information includes data on body mass, clutch size, diet, availability of data from the IUCN Red List on habitat systems, extent of occurrence, generation length, migration pattern, distribution, and biological data from the Demographic Species Knowledge Index, number of occurrences recorded by the Global Biodiversity Information Facility (GBIF) as well as genomic data from the Bird 10 000K Genomes (B10K) project, Vertebrate Genome Project (VGP) and GenBank. Information on invasive species is also part of this knowledge area. The Intrinsic Value category refers to two measures of the species' intrinsic value, namely Ecological and Evolutionary Distinctiveness. In order to make these knowledge areas comparable, we standardized data following the taxonomy of the Handbook of the Birds of the World and Birdlife (Version 4, 2019). The data enable a broad spectrum of analyses and will be useful to scientists for further research and to policymakers, zoos and other conservation stakeholders for future prioritization decisions.
    Matched MeSH terms: Introduced Species
  7. Vythalingam LM, Hossain MAM, Bhassu S
    Mol Cell Probes, 2021 02;55:101683.
    PMID: 33259896 DOI: 10.1016/j.mcp.2020.101683
    Invasive alien fish species have become a silent treat towards the ecosystem especially the native fish population in Malaysia. There has been a need to develop rapid identification methods that can aid management teams in identifying fish species that are not native to our ecosystem. Current visual identification methods are highly tedious and require time, delaying action towards curbing the invasion. The LAMP assay successfully identified six popular invasive fish species in Malaysia. None of the LAMP assays showed false positives and the Limit of Detection of the LAMP primers were highly sensitive and could detect DNA samples up to 1 × 10-15 ng/μl. The LAMP primers designed were highly specific to the target species and did not amplify non target species. DNA sequencing was done to ensure the accuracy of LAMP assay results. This study demonstrates that LAMP is a suitable tool in species identification efforts of invasive fish species in Malaysia.
    Matched MeSH terms: Introduced Species*
  8. Saba AO, Ismail A, Zulkifli SZ, Halim MRA, Wahid NAA, Amal MNA
    Sci Rep, 2020 10 14;10(1):17205.
    PMID: 33057156 DOI: 10.1038/s41598-020-74168-9
    The ornamental fish trade has been considered as one of the most important routes of invasive alien fish introduction into native freshwater ecosystems. Therefore, the species composition and invasion risks of fish species from 60 freshwater fish pet stores in Klang Valley, Malaysia were studied. A checklist of taxa belonging to 18 orders, 53 families, and 251 species of alien fishes was documented. Fish Invasiveness Screening Test (FIST) showed that seven (30.43%), eight (34.78%) and eight (34.78%) species were considered to be high, medium and low invasion risks, respectively. After the calibration of the Fish Invasiveness Screening Kit (FISK) v2 using the Receiver Operating Characteristics, a threshold value of 17 for distinguishing between invasive and non-invasive fishes was identified. As a result, nine species (39.13%) were of high invasion risk. In this study, we found that non-native fishes dominated (85.66%) the freshwater ornamental trade in Klang Valley, while FISK is a more robust tool in assessing the risk of invasion, and for the most part, its outcome was commensurate with FIST. This study, for the first time, revealed the number of high-risk ornamental fish species that give an awareness of possible future invasion if unmonitored in Klang Valley, Malaysia.
    Matched MeSH terms: Introduced Species*
  9. Patil JG, Norazmi-Lokman NH, Kwan TN
    Comp Biochem Physiol B Biochem Mol Biol, 2020 07 22;248-249:110468.
    PMID: 32710933 DOI: 10.1016/j.cbpb.2020.110468
    Hormonal sex reversal can produce monosex fish stocks and provide insights into their gamity and reproductive physiology. However, paradoxical effects have been reported in several fish species that remain largely ignored as anomalies, particularly those of masculinisation. As a first step, this study examined reproductive viability of paradoxically masculinised Gambusia holbrooki produced following oral administration (20-100 mg/kg feed) of a feminizing hormone diethylstilbestrol (DES). Contrary to expectation, all treatment groups produced 100% male populations. Survival, mating behaviour, gamete production, breeding output as well as expression of anti-Mullerian hormone (amh), ovarian (cyp19a1a) and brain (cyp19a1b) aromatase of masculinised fish were also examined. Survival (≤ 54.1 ± 7.3%) at termination of DES treatment was significantly lower compared with controls (88.6 ± 4.3%) but remained unaffected post treatment. Gonopodium thrusting frequency (33 ± 9.8 per 10 min) was not significantly different to untreated males just as sperm abundance (3.9 ± 1.5 × 108/male) and their motility (88.6 ± 29.1%). Importantly, paradoxically masculinised fish mated with virgin females and produced clutch sizes (22 ± 4) and progeny survival (87.0 ± %) that were comparable to that of untreated males. Masculinised testes showed high amh and low cyp19a1a expression, a pattern resembling those of untreated males. Production of paradoxically sex-reversed males with a capability to produce viable offspring has not been reported previously in this or other fish species. The outcomes support a feed-back regulation of oestrogenic pathways in this viviparous fish and could be useful for ecological applications such as controlling invasive fish populations.
    Matched MeSH terms: Introduced Species
  10. Ahmed A, Abu Bakar MS, Hamdani R, Park YK, Lam SS, Sukri RS, et al.
    Environ Res, 2020 07;186:109596.
    PMID: 32361527 DOI: 10.1016/j.envres.2020.109596
    Biochar production from invasive species biomass discarded as waste was studied in a fixed bed reactor pyrolysis system under different temperature conditions for value-added applications. Prior to pyrolysis, the biomass feedstock was characterized by proximate, ultimate, and heating value analyses, while the biomass decomposition behavior was examined by thermogravimetric analysis. The heating values of the feedstock biomass ranged from 18.65 to 20.65 MJ/kg, whereas the volatile matter, fixed carbon, and ash content were 61.54-72.04 wt %, 19.27-26.61 wt % and 1.51-1.86 wt %, respectively. The elemental composition of carbon, hydrogen, and oxygen in the samples was reported to be in the range of 47.41-48.47 wt %, 5.50-5.88 wt % and 46.10-45.18 wt %, respectively, while the nitrogen and sulphur content in the biomass samples were at very low concentrations, making it more useful for valorization from environmental aspects. The biochar yields were reported in the range of 45.36-58.35 wt %, 28.63-44.38 wt % and 22.68-29.42 wt % at a pyrolysis temperature of 400 °C, 500 °C, and 600 °C, respectively. The biochars were characterized from ultimate analysis, heating value, energy densification ratio, energy yield, pH, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy and energy dispersive X-ray spectrometry (SEM and EDX), to evaluate their potential for value-added applications. The carbon content, heating value, energy densification ratio, and the porosity of the biochars improved with the increase in pyrolysis temperature, while the energy yield, hydrogen, oxygen, and nitrogen content of the biochars decreased. This study revealed the potential of the valorization of underutilized discarded biomass of invasive species via a pyrolysis process to produce biochar for value-added applications.
    Matched MeSH terms: Introduced Species*
  11. Ahmad AK, Nur-Hazwani MNR, Aisyah Syed Omar S, Aweng ER, Taweel A
    Pak J Biol Sci, 2020 Jan;23(11):1374-1379.
    PMID: 33274864 DOI: 10.3923/pjbs.2020.1374.1379
    BACKGROUND AND OBJECTIVE: Malaysia reported experiencing serious invasive species intrusion in various rivers and threatening some local species to distinct. A study was undertaken to estimate and compare their composition and species richness in two pristine and two disturbed freshwater ecosystems.

    MATERIALS AND METHODS: Invasive and local species growth pattern was also estimated using length-weight analysis. Sampling was conducted using cast net and electric shock in each river twice in 12 months. Fish collected were identified, photo captured and measured for their weight and length. The growth pattern was also estimated using length-weight analysis.

    RESULTS: A total of 188 fishes were caught, comprises of 8 families and 15 species (ten local species with 119 individuals and five alien species with 69 individuals). Sistomus binotatus was the most dominant local species, whereas Tilapia nilotica was the most dominant alien species. There is no significant difference in composition between local and invasive species occur indicates the raise of alien species in those ecosystems even local species still dominated. The growth pattern for Sistomus binotatus and Clarias batrachus is isometric in the pristine ecosystem but negative isometric in disturbed rivers. Contrary, Tilapia nilotica has isometric for both ecosystems.

    CONCLUSION: This study concluded the capability and potential of colonization of alien species in stress ecosystem especially Tilapia nilotica. Thus, there is potential colonization of alien in Malaysia freshwater systems and a threat to local species due to food competition, site preferences and survival ability.

    Matched MeSH terms: Introduced Species*
  12. Fauzi Mohamed Yusof, Mohd Hafiz Mohd, Yazariah Mohd Yatim, Ahmad Izani Md. Ismail
    MATEMATIKA, 2020;36(1):1-14.
    MyJurnal
    In this paper, the combined influences of biotic interactions, environmental components and harvesting strategy on the spread of Hantavirus are investigated. By employing a multi-species model consisting of (susceptible and infected) rodents and alien species, we show that interspecific competition from alien species has an effect in reducing the spread of infection, and this species could be employed as a potential biocontrol agent. Our analysis using numerical continuation and simulation also reveals the conditions under which Hantavirus infection occurs and disappears as the environmental conditions and the intensity of harvesting change. Without harvesting, infection emerges when environments are conducive. Inclusion of moderate harvesting in favourable environments can lead to disappearance of infection among rodent species. However, as the intensity of harvesting increases, this situation can cause extinction of all rodents species and consequently, jeopardise biodiversity. Overall, our results demonstrate how the interplay of different factors can combine to determine the spread of infectious diseases.
    Matched MeSH terms: Introduced Species
  13. Mohd Zaideen IM
    Mar Pollut Bull, 2019 Nov;148:3-4.
    PMID: 31422300 DOI: 10.1016/j.marpolbul.2019.07.041
    The strategic location of Malaysia along the world's busiest trade waterways underscores the need to cope ballast water issues for both domestic and international shipping. The adoption of Ballast Water Management Convention 2004 (BWMC) by the International Maritime Organization is suitable for management plans intended to prevent the introduction of invasive species through ballast water discharge. Malaysia has ratified the BWMC in September 2010 and the Convention has come into force in September 2017. However up to now, the BWMC has not been fully implemented by Malaysia for ships operating in its waters. This paper analyse the headway in implementing the provisions of the BWMC in Malaysia as well as the issues and challenges encountered for the implementation. The paper concludes that Malaysian government should promulgate laws and policies to clearly communicate on ballast water issues to the shipping industry communities.
    Matched MeSH terms: Introduced Species*
  14. Wasserman RJ, Dick JTA, Welch RJ, Dalu T, Magellan K
    Conserv Biol, 2019 08;33(4):969-971.
    PMID: 30417437 DOI: 10.1111/cobi.13250
    Matched MeSH terms: Introduced Species*
  15. Jarić I, Heger T, Castro Monzon F, Jeschke JM, Kowarik I, McConkey KR, et al.
    Trends Ecol Evol, 2019 04;34(4):291-302.
    PMID: 30661709 DOI: 10.1016/j.tree.2018.12.008
    Ecological effects of alien species can be dramatic, but management and prevention of negative impacts are often hindered by crypticity of the species or their ecological functions. Ecological functions can change dramatically over time, or manifest after long periods of an innocuous presence. Such cryptic processes may lead to an underestimation of long-term impacts and constrain management effectiveness. Here, we present a conceptual framework of crypticity in biological invasions. We identify the underlying mechanisms, provide evidence of their importance, and illustrate this phenomenon with case studies. This framework has potential to improve the recognition of the full risks and impacts of invasive species.
    Matched MeSH terms: Introduced Species*
  16. Lim VC, Ramli R, Bhassu S, Wilson JJ
    PeerJ, 2018;6:e4572.
    PMID: 29607265 DOI: 10.7717/peerj.4572
    Background: Intense landscaping often alters the plant composition in urban areas. Knowing which plant species that pollinators are visiting in urban areas is necessary for understanding how landscaping impacts biodiversity and associated ecosystem services. The cave nectar bat,Eonycteris spelaea, is an important pollinator for many plants and is often recorded in human-dominated habitats. Previous studies of the diet ofE. spelaearelied on morphological identification of pollen grains found in faeces and on the body of bats and by necessity disregarded other forms of digested plant material present in the faeces (i.e., plant juice and remnants). The main objective of this study was to examine the diet of the nectarivorous bat,E. spelaea,roosting in an urban cave at Batu Caves, Peninsular Malaysia by identifying the plant material present in the faeces of bats using DNA metabarcoding.

    Methods: Faeces were collected under the roost ofE. spelaeaonce a week from December 2015 to March 2016. Plant DNA was extracted from the faeces, Polymerase chain reaction (PCR) amplified atITS2andrbcLregions and mass sequenced. The resultant plant operational taxonomic units were searched against NCBI GenBank for identification.

    Results: A total of 55 species of plants were detected from faeces ofE. spelaeaincludingArtocarpus heterophyllus, Duabanga grandifloraandMusaspp. which are likely to be important food resources for the cave nectar bat.

    Discussion: Many native plant species that had not been reported in previous dietary studies ofE. spelaeawere detected in this study includingBauhinia strychnoideaandUrophyllum leucophlaeum, suggesting thatE. spelaearemains a crucial pollinator for these plants even in highly disturbed habitats. The detection of many introduced plant species in the bat faeces indicates thatE. spelaeaare exploiting them, particularlyXanthostemon chrysanthus,as food resources in urban area. Commercial food crops were detected from all of the faecal samples, suggesting thatE. spelaeafeed predominantly on the crops particularly jackfruit and banana and play a significant role in pollination of economically important plants. Ferns and figs were also detected in the faeces ofE. spelaeasuggesting future research avenues to determine whether the 'specialised nectarivorous'E. spelaeafeed opportunistically on other parts of plants.

    Matched MeSH terms: Introduced Species
  17. Rama Rao S, Liew TS, Yow YY, Ratnayeke S
    PLoS One, 2018;13(5):e0196582.
    PMID: 29734361 DOI: 10.1371/journal.pone.0196582
    Invasive snails in the genus Pomacea have spread across Southeast Asia including Peninsular Malaysia. Their effects on natural and agricultural wetlands are appreciable, but species-specific effects are less clear because of morphological similarity among the species. Our objective was to establish diagnostic characteristics of Pomacea species in Malaysia using genetic and morphological criteria. The mitochondrial COI gene of 52 adult snails from eight localities in Peninsular Malaysia was amplified, sequenced, and analysed to verify species and phylogenetic relationships. Shells were compared using geometric morphometric and covariance analyses. Two monophyletic taxa, P. canaliculata and P. maculata, occurred in our samples. The mean ratio of shell height: aperture height (P = 0.042) and shell height: shell width (P = 0.007) was smaller in P. maculata. P. maculata co-occurred with P. canaliculata in five localities, but samples from three localities contained only P. canaliculata. This study is the first to confirm the presence of two of the most invasive species of Pomacea in Peninsular Malaysia using a molecular technique. P. canaliculata appears to be the more widespread species. Despite statistical differences, both quantitative and qualitative morphological characteristics demonstrated much interspecific overlap and intraspecific variability; thus, shell morphology alone cannot reliably verify species identity. Molecular techniques for distinguishing between these two highly invasive Pomacea species are needed to understand their specific ecological niches and to develop effective protocols for their management.
    Matched MeSH terms: Introduced Species
  18. Pipatchartlearnwong K, Swatdipong A, Vuttipongchaikij S, Apisitwanich S
    BMC Genet, 2017 10 12;18(1):88.
    PMID: 29025415 DOI: 10.1186/s12863-017-0554-y
    BACKGROUND: Borassus flabellifer or Asian Palmyra palm is an important crop for local economies in the South and Southeast Asia for its fruit and palm sugar production. Archeological and historical evidence indicated the presence of this species in Southeast Asia dating back at least 1500 years. B. flabellifer is believed to be originated in Africa, spread to South Asia and introduced into Southeast Asia through commercial routes and dissemination of cultures, however, the nature of its invasion and settlement in Thailand is unclear.

    RESULTS: Here, we analyzed genetic data of 230 B. flabellifer accessions across Thailand using 17 EST-SSR and 12 gSSR polymorphic markers. Clustering analysis revealed that the population consisted of two genetic clusters (STRUCTURE K = 2). Cluster I is found mainly in southern Thailand, while Cluster II is found mainly in the northeastern. Those found in the central are of an extensive mix between the two. These two clusters are in moderate differentiation (F ST = 0.066 and N M = 3.532) and have low genetic diversity (HO = 0.371 and 0.416; AR = 2.99 and 3.19, for the cluster I and II respectively). The minimum numbers of founders for each genetic group varies from 3 to 4 individuals, based on simulation using different allele frequency assumptions. These numbers coincide with that B. flabellifer is dioecious, and a number of seeds had to be simultaneously introduced for obtaining both male and female founders.

    CONCLUSIONS: From these data and geographical and historical evidence, we hypothesize that there were at least two different invasive events of B. flabellifer in Thailand. B. flabellifer was likely brought through the Straits of Malacca to be propagated in the southern Thailand as one of the invasive events before spreading to the central Thailand. The second event likely occurred in Khmer Empire, currently Cambodia, before spreading to the northeastern Thailand.

    Matched MeSH terms: Introduced Species*
  19. Nally JE, Arent Z, Bayles DO, Hornsby RL, Gilmore C, Regan S, et al.
    PLoS Negl Trop Dis, 2016 12;10(12):e0005174.
    PMID: 27935961 DOI: 10.1371/journal.pntd.0005174
    The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.
    Matched MeSH terms: Introduced Species
  20. Gan HM, Gan HY, Lee YP, Grandjean F, Austin CM
    PMID: 25648916 DOI: 10.3109/19401736.2015.1007326
    The invasive freshwater crayfish Orconectes limosus mitogenome was recovered by genome skimming. The mitogenome is 16,223 base pairs in length consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The O. limosus mitogenome has an AT bias of 71.37% and base composition of 39.8% for T, 10.3% for C, 31.5% for A, and 18.4% for G. The mitogene order is identical to two other genera of northern hemisphere crayfish that have been sequenced for this organelle.
    Matched MeSH terms: Introduced Species
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