Multiple Invasions Research Articles

First molecular evidence of Penthaleus major (Dugés) (Penthaleidae) in Brazil

Penthaleus major (Dugés) (Penthaleidae) is an invasive pest in Brazil, first detected in 2009, attacking oat plants in Rio Grande do Sul, southern Brazil. This pest went unnoticed for almost 12 years until 2020 when suspected specimens of a blue mite were collected on oat plants in the municipalities of André da Rocha and Cachoeira do Sul, Rio Grande do Sul state, Brazil. Genomic DNA was extracted from these specimens and used for PCR amplification of a region of the mitochondrial gene Cytochrome Oxidase I (COI). The amplified fragments were sequenced, and the genetic sequences obtained were compared with those in GenBank. The results confirm, for the first time, the presence of the species P. major in Brazil using DNA barcoding. Further analysis revealed the presence of a single and specific haplotype in the country, suggesting either a single invasion or multiple invasions with the same maternal lineage.

Disentangling the worldwide invasion process of Halyomorpha halys through approximate Bayesian computation.

Halyomorpha halys is a polyphagous insect pest, which was first found outside its native regions in 1996, and since then it has rapidly spread worldwide causing damage to agriculture. Investigating the genetic diversity among H. halys populations is essential to understand the colonization history out of its native areas. Analyses based on mtDNA indicate multiple invasions from Asia to European and American continents, as well as serial invasions within invaded countries, but the colonization dynamics are still debated. Recently, genome-wide data (ddRAD) have been published to investigate the genomic structure of H. halys, proposing China as a putative source of multiple serial invasion events to Europe and the Americas. In this study we re-analyze published ddRAD sequences from worldwide populations of H. halys to better elucidate the colonization process. We assessed the genetic diversity in native populations identifying genetic differentiation between populations in China. Furthermore, we observed a complex pattern of population structure in the invaded countries, that may have originated from the occurrence of multiple independent colonization waves through time, from sub-populations present in the native range to Europe and the Americas. We tested alternative colonization hypotheses through Approximate Bayesian Computation comparison of demographic scenarios. Our results support multiple waves of migration from East China to invaded territories and the occurrence of European and American bridgehead effects. These results underline the importance of demographic inference through genome-wide data to investigate biological invasions, whose knowledge become fundamental to establish new strategies of management and control of invasive species.

Multiple origins of freshwater invasion and parental care reflecting ancient vicariances in the bivalve family Cyrenidae (Mollusca)

Habitat transitions in living organisms are key innovations often coupled with species diversification after their successful adaptation to new environment. The Cyrenidae is among the most well-known heterodont bivalve groups that have successfully invaded freshwater systems from brackish water environments and display diverse lineage-specific developmental modes. Phylogenetic and molecular clock-based divergence time analyses using 12 complete mitochondrial genome sequences suggest that Cyrenidae species independently colonized freshwater habitats during three distinct spatial and geological periods: one from the American continents approximately in the Early Jurassic and the two others from Australasian/East Asian continents in the Early/Middle Cretaceous and the Paleogene-Neogene boundary, respectively. This study provides significant insight into the temporal and spatial patterns of multiple freshwater invasions, aligning with ancient vicariance events inferred from different geological timelines of plate tectonics. Additionally, mitogenome phylogeny confirms the earlier hypothesis of the repeated parallel evolution of parental care system within this bivalve group.

Minimally invasive elective gastrectomy after preoperative chemotherapy in a patient with frailty who presented with locally far advanced-stage gastric cancer: a case report

BackgroundHerein, we report a case of gastric antrum cancer with multiple invasions to other organs that was completely cured with laparoscopic distal gastrectomy after preoperative chemotherapy in a patient with poor general condition.Case presentationAn 80-year-old male patient was diagnosed with anemia during follow-up for cerebral lacunar infarction at another hospital. He was diagnosed with advanced-stage gastric antrum cancer and was referred to our hospital. On esophagogastroduodenoscopy, type 2 advanced-stage gastric cancer was detected at the greater curvature of the antrum, and the biopsy results revealed tubular adenocarcinoma. Contrast-enhanced computed tomography scan revealed multiple invasions to other organs, thick gastric wall with contrast effect, and superior mesenteric vein tumor thrombus. However, there was no evidence of distant metastasis on positron emission tomography/computed tomography scan. The clinical diagnosis was stage IVA gastric cancer. Pancreatoduodenectomy with portal vein resection could be important at this point. However, preoperative chemotherapy with S-1 and oxaliplatin was administered instead of performing extended surgery because the patient had poor general condition (performance status score of 3). The patient received three cycles of preoperative chemotherapy at the hospital along with rehabilitation and nutritional management with oral nutritional supplements. After treatment, the performance status score of the patient improved from 3 to 1. Furthermore, in terms of clinical therapeutic effect, the patient achieved partial response. Hence, laparoscopic distal gastrectomy with D2 lymph node dissection and partial transverse colectomy was performed. After surgery, the patient was admitted for oral intake on postoperative day 6 and was discharged on postoperative day 21. Based on the histopathological examination, gastric cancer had disappeared, and there were no evident malignant findings. Therefore, gastric cancer was classified as grade 3 according to the histological treatment efficacy criteria. The patient did not present with recurrence at 2 years after surgery.ConclusionsBy actively administering preoperative chemotherapy, minimally invasive radical surgery with maximum preservation of the surrounding organs can be performed for locally far advanced-stage gastric cancer in older patients with poor general condition.

Hot springs viruses at Yellowstone National Park have ancient origins and are adapted to thermophilic hosts

Geothermal springs house unicellular red algae in the class Cyanidiophyceae that dominate the microbial biomass at these sites. Little is known about host-virus interactions in these environments. We analyzed the virus community associated with red algal mats in three neighboring habitats (creek, endolithic, soil) at Lemonade Creek, Yellowstone National Park (YNP), USA. We find that despite proximity, each habitat houses a unique collection of viruses, with the giant viruses, Megaviricetes, dominant in all three. The early branching phylogenetic position of genes encoded on metagenome assembled virus genomes (vMAGs) suggests that the YNP lineages are of ancient origin and not due to multiple invasions from mesophilic habitats. The existence of genomic footprints of adaptation to thermophily in the vMAGs is consistent with this idea. The Cyanidiophyceae at geothermal sites originated ca. 1.5 Bya and are therefore relevant to understanding biotic interactions on the early Earth.

Genomes of historical specimens reveal multiple invasions of LTR retrotransposons in Drosophila melanogaster during the 19th century

Transposable element invasions have a profound impact on the evolution of genomes and phenotypes. It is thus an important open question how often such TE invasions occur. To address this question, we utilize the genomes of historical specimens, sampled about 200 y ago. We found that the LTR retrotransposons Blood, Opus, and 412 spread in Drosophila melanogaster in the 19th century. These invasions constitute second waves, as degraded fragments were found for all three TEs. The composition of Opus and 412, but not of Blood, shows a pronounced geographic heterogeneity, likely due to founder effects during the invasions. Finally, we identified species from the Drosophila simulans complex as the likely origin of the TEs. We show that in total, seven TE families invaded D. melanogaster during the last 200y, thereby increasing the genome size by up to 1.2Mbp. We suggest that this high rate of TE invasions was likely triggered by human activity. Based on the analysis of strains and specimens sampled at different times, we provide a detailed timeline of TE invasions, making D. melanogaster the first organism where the invasion history of TEs during the last two centuries could be inferred.

Multiple invasions and predation: The impact of the crayfish Cherax quadricarinatus on invasive and native snails.

The pace of biological invasions has increased in recent decades, leading to multiple invasions and the potential dominance of invasive species, destabilizing local ecological networks. This provides opportunities to study new ecological species interactions, including predation. Tropical freshwaters have been particularly concerned by aquatic invasions and we focused here on the Martinique island (Lesser Antilles). We examined the predator-prey relationships involving invasive Thiarid snails (Tarebia granifera and Melanoides tuberculata) and the native Neritina punctulata, both confronted with a newcomer predator, the redclaw crayfish (Cherax quadricarinatus). We conducted several mesocosm experiments to assess the impact of crayfish predation on snail survival and the passive and active antipredator responses of snails. A first experiment indicated snail survival rates between 50% and 80%, depending on crayfish size and sex. Notably, there was a negative correlation between snail survival and male crayfish size and the predation method (shell crushing vs. "body sucking") varied with crayfish size. The second experiment suggested no refuge size for snails, with both very small (<5 mm) and very large (>5 mm) unable to escape predation, regardless of crayfish size (from 77 to 138 mm) or sex. Finally, we investigated the escape behavior of Thiarids regarding three crayfish cues. Melanoides tuberculata tend to bury in the substrate and T. granifera to climb up aquarium walls, what was expected from their shell morphologies, and both responding to crayfish cues within minutes. Overall, C. quadricarinatus proves to be an efficient snail predator with limited escape options for snails, potentially contributing to the decline of certain snail populations in Martinique. This omnivorous predator might impact other native species across different groups, including shrimps and fish. Our study underscores the urgent need for monitoring efforts, solidifying the redclaw crayfish reputation as a dangerous invasive species for freshwater macrobenthic faunas worldwide.

DNA barcoding indicates multiple invasions of the freshwater snail Melanoides tuberculata sensu lato in Florida.

Melanoides tuberculata sensu lato (Thiaridae) are polymorphic female-clonal snails of Asian and African origins that have invaded freshwaters worldwide, including those in Florida. Although the snails have been documented in Florida for at least 70 years, no studies have investigated whether the observed distribution is due to a single introduction or multiple independent invasions. Here, cytochrome oxidase I was used to measure genetic diversity within and among sites in Florida and compare genetic diversity between Florida and other regions of the world. We also examined the relationship between shell morphology and haplotype diversity to determine if shell morphs can serve as a proxy for haplotypes. In total, we recovered 8 haplotypes randomly distributed across populations in Florida. Phylogenetic reconstruction supported the hypothesis of multiple invasions by diverse representatives of the M. tuberculata species complex. In contrast, shell morphology was not found to be a useful phylogeographic character, with divergent haplotypes represented by similar shell forms. These results suggest that the observed invasion patterns in Florida are best explained by serial introductions, and that shell morphology cannot be used to predict haplotypes or reconstruct invasion history of Melanoides tuberculata s.l. and that extensive taxonomic revisions are needed to investigate invasion dynamics.

The Theme of Indianism in the Selected Works of Upamanyu Chatterjee

One of the most accomplished and prolific contemporary Indian writers of English is Upamanyu Chatterjee. With a strong sociocultural and Indian foundation, Chatterjee’s fields of expertise encompass a wide range of subjects while remaining deeply influenced by the rich legacy of Indian culture. The Spiritualism and nationalism are included on this list. For him, just like for Aurobindo Ghosh, nationalism entails a genuine dedication to one’s country and its people, regardless of their race, gender, caste, or place in society. India is a nation that embraces many languages, cultures, and religions. Religion- and culture-related disputes have always arisen. The conservative and narrow-minded religious leaders and politicians frequently have mislead the populace, which occasionally have caused riots. Upamanyu Chatterjee asserts that in a country with as many cultures as India, riots are inevitable. India has continued to expand over time despite being the target of multiple invasions and incursions. India’s greatest asset is its spirituality. It has been reinforced by them in all attacks, both internal and external. According to Upamanyu Chatterjee, the evil forces endangering the peace and harmony of the nation can be vanquished by grasping the core values of Indian culture. The comparison and analysis of the nationalistic and spiritualist ethos found in the selected works of Upamanyu Chatterjee is the main goal of this research project.

Defaunated and invaded insular tropical rainforests will not recover alone: Recruitment limitation factors disentangled by hierarchical models of spontaneous and assisted regeneration

Abstract Most tropical forests are now severely degraded and their ability to recover is highly dependent on frugivores which ensure seed dispersal for most woody plants. The global collapse of large vertebrates therefore raises major concerns about tropical forest succession, but few field studies have been conducted to disentangle recruitment limitations during disrupted succession. This study took place on Réunion (Mascarenes) where all large native frugivores have been extinct since human colonisation in 1665 and where multiple invasions threaten native ecosystems. We set up 20 experimental blocks on a lava flow dated back to 1800, in plant‐impoverished post‐defaunation vegetation bordered by old‐growth forests. We assessed fecundity, seed dispersal and seedling recruitment of the complete fleshy‐fruited plant community and used Bayesian analyses to disentangle the impact of multiple factors on these key processes. In the same blocks, we sowed four native trees assumed to be disperserless to test their capacity to establish, controlling for two additional post‐dispersal limitations (seed predation and competition with invasive plants). On the flow, small‐seeded native plants were fairly dispersed but did not recruit, probably due to strong competition with invasive plants; the few native species that recruited somehow were mostly medium‐seeded plants that were still dispersed; large‐seeded plants were absent from seed rain (which shows that invasive frugivores did not replace extinct ones) and subsequently from spontaneous recruitment. Instead, some alien plants, notably the tiny‐seeded highly dispersed Clidemia hirta and the medium‐seeded Psidium cattleianum largely dominated seedling recruitment. Native plants recruited better at the forest margin, including some large‐seeded species nearby mother trees. Sown large‐seeded species were able to emerge and survive in all plots whatever the treatment, which demonstrates that dispersal loss was the primary cause of regeneration failure on the flow. Synthesis. The strong modulation of the establishment capacity of native plants by seed mass shows that invasive plants win by forfeit of large‐seeded plants after native frugivores loss. Our study emphasises the fundamental role of dispersal loss and competition with invasive plants in the disruption of ecological succession, as well as the urgency of restoring seed dispersal and strengthening biosecurity regulations.

Genomic Basis of Freshwater Adaptation in the Palaemonid Prawn GenusMacrobrachium: Convergent Evolution Following Multiple Independent Colonization Events.

Adaptation to different salinity environments can enhance morphological and genomic divergence between related aquatic taxa. Species of prawns in the genus Macrobrachium naturally inhabit different osmotic niches and possess distinctive lifecycle traits associated with salinity tolerance. This study was conducted to investigate the patterns of adaptive genomic divergence during freshwater colonization in 34 Macrobrachium species collected from four continents; Australia, Asia, North and South America. Genotyping-by-sequencing (GBS) technique identified 5018 loci containing 82,636 single nucleotide polymorphisms (SNPs) that were used to reconstruct a phylogenomic tree. An additional phylogeny was reconstructed based on 43 candidate genes, previously identified as being potentially associated with freshwater adaptation. Comparison of the two phylogenetic trees revealed contrasting topologies. The GBS tree indicated multiple independent continent-specific invasions into freshwater by Macrobrachium lineages following common marine ancestry, as species with abbreviated larval development (ALD), i.e., species having a full freshwater life history, appeared reciprocally monophyletic within each continent. In contrast, the candidate gene tree showed convergent evolution for all ALD species worldwide, forming a single, well-supported clade. This latter pattern is likely the result of common evolutionary pressures selecting key mutations favored in continental freshwater habitats Results suggest that following multiple independent invasions into continental freshwaters at different evolutionary timescales, Macrobrachium taxa experienced adaptive genomic divergence, and in particular, convergence in the same genomic regions with parallel shifts in specific conserved phenotypic traits, such as evolution of larger eggs with abbreviated larval developmental.

Epidemiology, clinical manifestations, and laboratory findings of 1,590 human brucellosis cases in Ningxia, China

IntroductionEpidemiological and clinical analyses of brucellosis are vital for public health leaders to reinforce disease surveillance and case management strategies.MethodsIn this study, we aimed to analyse the epidemiology and clinical features of 1,590 cases of human brucellosis.ResultsApproximately 72.08% (1,146) of the patients were male and 27.92% (444) were female. At least 88.18% (1,402/1,590) of the patients had a history of contact with sheep/goats and cattle, which was identified as the main risk factor for infection. The most common age group affected was 30–69 years, comprising 83.90% of all cases, with a median age of 47.3 years. Meanwhile, 75.03% (1,193/1,590) of the patients were farmers, followed by workers (10.50%, 167/1,590). The spectrum of clinical manifestations varied, and the major symptoms were fatigue (42.96%), joint pain (37.30%), and fever (23.33%). Arthritis was diagnosed in 989 patients, spondylitis was diagnosed in 469 patients, and external genital complications were found in at least 53.96% (858/1,590) of patients. In addition, approximately 41.25% (625/1,515) and 24.53% (390/1,590) of cases exhibited elevated CRP and D-dimer levels, respectively. Conversely, a significant decrease was observed in fibrinogen, total protein, and albumin levels, affecting 48.36% (769/1,590), 77.30% (1,226/1,586), and 91.80% (1,456/1,586) of the patients, respectively. These data demonstrate that brucellosis is a severe wasting disease that leads to an imbalance in nutritional metabolism and a decline in immunity. In total, 86.73% (1,379/1,590) of patients showed improvement with antibiotic therapy, while 13.27% (211/1,590) of patients experienced relapses or treatment failure.ConclusionBrucellosis often presents with non-specific symptoms and laboratory findings, accompanied by multiple organ invasions, as well as being a vital challenge for diagnosis and treatment; thus, it is essential for a high degree of suspicion to be placed on brucellosis for a timely diagnosis and treatment. This study provides basic data and resources for developing tailored countermeasures to curb its further spread.

Genetic variability of the honey bee mite, Varroa destructor, from a humid continental climatic region of Canada, and temperate and tropical climatic regions of Mexico.

Varroa destructor is a damaging mite of Western honey bees (Apis mellifera). Genetic variability of the mite in different regions of the world could be related to the movement of infested bees or other factors, such as climate. In this study, V. destructor samples were collected from tropical and temperate climate regions of Mexico, and a humid continental climate region of Canada. COX-1 AFLPs showed that all the mites were the Korean haplotype. Four microsatellites revealed nine haplogroups from the continental climate region of Canada, compared to three haplogroups from the tropical and temperate climate regions of Mexico. CytII-ATP sequences showed seven haplogroups from the humid continental climate region vs. two haplogroups from the temperate region and one haplogroup from the tropical region. CytB sequences revealed seven haplogroups from Canada vs. three from Mexico. A comparison of the cytB sequences of the samples from Canada and Mexico to those from a worldwide collection showed that one sequence, designated the cytB1 type, predominated, comprising 57% of the 86 sequences; it clustered with similar sequences that comprised 80% of the sequences, designated family A. CytB1 was predominant in Mexico, but not in Canada. The other 20% of sequences were in families B and C, and all those samples originated from East and Southeast Asia. The microsatellite, cytII-ATP, and cytB markers, all showed higher variability in mites collected in Canada than in Mexico, which could be related to the cooler climate or an earlier invasion and/or multiple mite invasions in Canada.

Distribution, drivers and restoration priorities of plant invasions in India

Abstract Biological invasions threaten biodiversity and human wellbeing, with developing tropical countries being more vulnerable. Despite the urgency to reduce impacts of invasions, management interventions are constrained by unavailability of timely information on invasive species occurrence, potential drivers and restoration priorities. Generating this information at biogeographic scales can be costly, unless integrated with multi‐objective biodiversity monitoring. Invasive plant monitoring is integrated with India's national‐scale tiger population assessment, wherein natural areas are sampled at 25 km2 scale to inventory plants. In 2018, a total of 158,979 plots were sampled covering ~358,550 km2. We used 206,393 locations of high concern invasive plants to model their distribution using socio‐ecological covariates and identify potential drivers of invasions. Considering the invasion magnitude and financial constraints in management, we further identified priority restorations sites at national‐scale to maximise biodiversity outcomes. High‐concern invasive plants were recorded from ~254,880 km2 (72% sampled area) and modelled to invade in total ~750,905 km2 (66%) Indian natural systems. While open and deciduous ecosystems were the highest invaded by woody plants, areas with extreme climate and less anthropic pressure were least invaded. Since managing invasions across their range seemed futile due to costly (~13.5 billion USD for one‐time management) and ineffective strategies, restoration priority was assigned to least invaded areas (11% protected areas, 23% multi‐use) to maximise biodiversity returns. Synthesis and applications: India implemented national‐scale invasive plant monitoring by integrating it with the umbrella project on tiger assessment. Embarking on this big data, we show that two‐thirds of India's natural areas are under multiple plant invasions, owing to the legacy of anthropogenic modifications. Our study offers a restoration priority model, empowering policymakers to devise adaptive strategies for restoring invaded biomes and maximizing biodiversity returns.

Prevalence of Amphistomes and Fasciola in large ruminants reared by smallholders in Lampung and Banten Provinces, Indonesia.

Parasitic diseases, including trematode invasions, result in losses to livestock in Indonesia, hindering the government's efforts to achieve meat self-sufficiency. This study aimed to estimate the prevalence of Amphistomes and Fasciola in large ruminants reared by smallholder farmers. Fecal samples from 199 buffalo and cattle were collected from the districts of East Lampung (Lampung Province) and Lebak (Banten Province). Fecal samples were examined for the presence of trematode eggs using a sedimentation technique. Parasite invasion rate was 48.2% (95% confidence interval [CI]: 41.3%-55.2%). Rate of invasion was 63.3% (95% CI: 52.7%-73.9%) in Lampung and 38.3% (95% CI: 29.6%-47.0%) in Lebak-Banten. The prevalence of multiple invasions of both Amphistomes and Fasciola was 20% in buffalo and local cattle, whereas invasion rate was 12.8% in crossbred cattle. Invasion rate of Amphistomes alone was 27.1%, and that of Fasciola was 4.5%. A higher invasion rate of Amphistomes (29.8%) occurred in crossbred animals. There were no significant differences between age groups for trematode invasion. The Chi-square test showed that the prevalence of trematode invasion in females was significantly higher than in males (51.5% and 30.0%, respectively). Amphistomes more commonly infected females than males (29.0% and 16.7%, respectively). All breeds were vulnerable to invasion by both trematode species and single invasions with different invasion rates. These findings contribute to determining the magnitude of the disease and provide a basis for studies on prevention and treatment of trematode invasion.

Niche dynamics along two centuries of multiple crayfish invasions.

The realised ecological niches of species may change in response to dynamic abiotic and biotic environments, particularly under fast global change. To fully understand the dynamics of niche features and their drivers, it is essential to have a long-term view of species distributions and the factors that may have influenced them. Here, we analysed the distribution and niche dynamics of the Italian crayfish (Austropotamobius fulcisianus) in the Iberian Peninsula over the past 200 years. The Italian crayfish was introduced to Spain in the 16th century, and spread due to multiple stocking events until the 1970s, when two North American crayfish (red swamp crayfish Procambarus clarkii, and signal crayfish Pacifastacus leniusculus) were introduced. Both North American species are carriers of a pathogen (Aphanomyces astaci, the causal agent of crayfish plague) lethal to the Italian crayfish. We hypothesised that the realised niche of the Italian crayfish, both in breadth and in position, has changed over time following changes in its range. The distribution of the Italian crayfish expanded from the mid-19th century until the mid-20th century, in association with an enlargement of its realised niched, mostly towards less abrupt and more coastal-influenced areas. After the introduction of the North American crayfishes, the collapse of the Italian crayfish involved a niche shift towards rough terrains in mountain areas. North American crayfish have eventually occupied most of the Italian crayfish's niche space, with the few no-coexistence areas being relegated to the most abrupt and high-elevation territories. Our historical approach allowed us to document and understand the highly dynamic distribution and niche of the Italian crayfish in the presence of invader counterparts, and to explore the environmental conditions under which their coexistence is minimised.

Diversity, phylogeny, and bathymetric zonation of Sirsoe (Annelida: Hesionidae) from colonization experiments in the South China Sea, with the description of three new species.

The South China Sea (SCS) basin is hypothesized to host distinct and bathymetrically differentiated fauna due to its semi-enclosed basin and three-layer circulation system. To test this hypothesis, three cow falls are artificially deployed at separate depths (655, 1604, and 3402 m) on Zhongnan seamount in the middle SCS, and the associated worms, Sirsoe spp. are selected as targets to explore their diversity, phylogeny, and zonation pattern. Analyses of collected specimens reveal three new Sirsoe species, which were then nominally described and named as S. polita sp. nov. (655 m), S. nanhaiensis sp. nov. (1604 and 3402 m), and S. feitiana sp. nov. (3402 m), and one known species (S. balaenophila lineage II). Metabarcoding analyses on cow-fall sediments reveal seven additional Operated Taxonomic Units (OTUs) assigned to Sirsoe, increasing the Sirsoe diversity to 10 species/OTUs in the middle SCS. Their distribution along depth shows increasing diversity toward the deeper sites. Phylogenetic inferences recover S. polita closely related to S. alucia from the Southwest Atlantic, forming a lineage deeply divergent from others. The nine deep-water species/OTUs are scattered in three distinct lineages showing closer phylogenetic relationships between 1604- and 3402-m counterparts. The lineage formed by S. naihaiensis and S. feitiana is distinct from other non-SCS congeners both morphologically and genetically. These results suggest multiple independent invasions of Sirsoe to the SCS, a new lineage potentially endemic to the SCS, and a strong zonation pattern related to depth, especially between the shallow (655 m) and the deep (1604 and 3402 m) sites. The semi-enclosed feature combined with the physical structure of the SCS may contribute to such a pattern. This work is registered in ZooBank under: urn:lsid:zoobank.org:pub:317771C8-42D717-4765-A168-B3BE99B09FBF.

Evolution of piggyBac Transposons in Apoidea

In this study, we investigated the presence of piggyBac (PB) transposons in 44 bee genomes from the Apoidea order, which is a superfamily within the Hymenoptera, which includes a large number of bee species crucial for pollination. We annotated the PB transposons in these 44 bee genomes and examined their evolution profiles, including structural characteristics, distribution, diversity, activity, and abundance. The mined PB transposons were divided into three clades, with uneven distribution in each genus of PB transposons in Apoidea. The complete PB transposons we discovered are around 2.23-3.52 kb in length and encode transposases of approximately 580 aa, with terminal inverted repeats (TIRs) of about 14 bp and 4 bp (TTAA) target-site duplications. Long TIRs (200 bp, 201 bp, and 493 bp) were also detected in some species of bees. The DDD domains of the three transposon types were more conserved, while the other protein domains were less conserved. Generally, most PB transposons showed low abundance in the genomes of Apoidea. Divergent evolution dynamics of PB were observed in the genomes of Apoidea. PB transposons in some identified species were relatively young, whiles others were older and with some either active or inactive. In addition, multiple invasions of PB were also detected in some genomes of Apoidea. Our findings highlight the contribution of PB transposons to genomic variation in these species and suggest their potential as candidates for future gene transfer tools.

Twenty-eight years of ecosystem recovery and destabilisation: Impacts of biological invasions and climate change on a temperate river

Most river ecosystems are exposed to multiple anthropogenic stressors affecting the composition and functionality of benthic communities. Identifying main causes and detecting potentially alarming trends in time depends on the availability of long-term monitoring data sets. Our study aimed to improve the knowledge about community effects of multiple stressors that is needed for effective, sustainable management and conservation. We conducted a causal analysis to detect the dominant stressors and hypothesised that multiple stressors, such as climate change and multiple biological invasions, reduce biodiversity and thus endanger ecosystem stability. Using a data set from 1992 to 2019 for the benthic macroinvertebrate community of a 65-km stretch of the upper Elbe river in Germany, we evaluated the effects of alien species, temperature, discharge, phosphorus, pH and abiotic conditional variables on the taxonomic and functional composition of the benthic community and analysed the temporal behaviour of biodiversity metrics. We observed fundamental taxonomic and functional changes in the community, with a shift from collectors/gatherers to filter feeders and feeding opportunists preferring warm temperatures. A partial dbRDA revealed significant effects of temperature and alien species abundance and richness. The occurrence of distinct phases in the development of community metrics suggests a temporally varying impact of different stressors. Taxonomic and functional richness responded more sensitively than the diversity metrics whereas the functional redundancy metric remained unchanged. Especially the last 10-year phase, however, showed a decline in richness metrics and an unsaturated, linear relationship between taxonomic and functional richness, which rather indicates reduced functional redundancy. We conclude that the varying anthropogenic stressors over three decades, mainly biological invasions and climate change, affected the community severely enough to increase its vulnerability to future stressors. Our study highlights the importance of long-term monitoring data and emphasises a careful use of biodiversity metrics, preferably considering also community composition.

Contrasting Patterns of Single Nucleotide Polymorphisms and Structural Variation Across Multiple Invasions.

Genetic divergence is the fundamental process that drives evolution and ultimately speciation. Structural variants (SVs) are large-scale genomic differences within a species or population and can cause functionally important phenotypic differences. Characterizing SVs across invasive species will fill knowledge gaps regarding how patterns of genetic diversity and genetic architecture shape rapid adaptation under new selection regimes. Here, we seek to understand patterns in genetic diversity within the globally invasive European starling, Sturnus vulgaris. Using whole genome sequencing of eight native United Kingdom (UK), eight invasive North America (NA), and 33 invasive Australian (AU) starlings, we examine patterns in genome-wide SNPs and SVs between populations and within Australia. Our findings detail the landscape of standing genetic variation across recently diverged continental populations of this invasive avian. We demonstrate that patterns of genetic diversity estimated from SVs do not necessarily reflect relative patterns from SNP data, either when considering patterns of diversity along the length of the organism's chromosomes (owing to enrichment of SVs in subtelomeric repeat regions), or interpopulation diversity patterns (possibly a result of altered selection regimes or introduction history). Finally, we find that levels of balancing selection within the native range differ across SNP and SV of different classes and outlier classifications. Overall, our results demonstrate that the processes that shape allelic diversity within populations is complex and support the need for further investigation of SVs across a range of taxa to better understand correlations between often well-studied SNP diversity and that of SVs.