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1.
PeerJ ; 12: e17763, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39221261

RESUMO

Mesophotic Coral Ecosystems (MCEs) represent unique ecological habitats that range from 30 to 150 m deep, harbouring phylogenetically distinct species and offering refuge for many taxa during times of environmental stress. Yet owing to inaccessibility of ecosystems at these depths, most MCEs remain unexplored, with quantifications of ecological communities in these habitats lacking across many regions. Here, using open- and closed-circuit technical diving, we quantified benthic and fish community composition at four mesophotic reef sites (45 m depth) in Grand Cayman. We show significant differences in benthic community composition over a small spatial scale driven by disparate coverage of sponges, crustose coralline algae, and sand/rubble, yet consistent patterns of macroalgal dominance representing >50% coverage at each site and low hard coral cover at an average of 2.4%. Reef fish species richness, biomass, and density was consistent across sites, however the relative contribution of individual species to community composition differed significantly. Macrocarnivores were found to be the dominant contributors to biomass, with invertivores the most speciose, and omnivores and planktivores at the highest densities, consistent with previous descriptions of mesophotic fish assemblages in other regions. Similarly, the low hard coral cover and high macroalgae and sponge cover of the benthic communities also appear ecologically similar to several described mesophotic reefs yet is not uniform across the Caribbean. The ecological organisation of Grand Cayman's MCEs may result from a variety of factors such as isolation from other major land masses, geology, local geography, and anthropogenic activity at both the local and global scale and highlight the importance of continued exploration and documentation of MCE communities.


Assuntos
Recifes de Corais , Peixes , Animais , Biodiversidade , Biomassa , Ecossistema , Poríferos/classificação , Poríferos/fisiologia , Alga Marinha/genética , Alga Marinha/fisiologia , Região do Caribe
2.
Int J Parasitol Parasites Wildl ; 25: 100974, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39257917

RESUMO

The Argentine shortfin squid Illex argentinus is one of the most important commercial species for the Argentine fisheries. The understanding of its stock structure is therefore necessary to ensure fishery sustainability and, given the relevance of squids in the regional food web, for biodiversity conservation. An overlap between parasitology and fisheries lies in the use of parasites as biological tags to identify the stock composition of exploited resources, however, the efficiency of this methodology has been questioned for stock assessment in cephalopods. In this work, the value of parasite assemblages of I. argentinus to discriminate between the co-occurring summer spawning stock (SSS) and south patagonic stock (SPS) in a mixing area over the Patagonian continental shelf during summer was evaluated for two cohorts. Five shortfin squid samples corresponding to SSS and SPS were examined for metazoan parasites. The squid size affected the parasite assemblage similarities, conversely, no gender effect on the infracommunities was observed. Multivariate analysis evidenced similarity in parasite assemblage composition and structure between both stocks captured in the mixing area on the same date. This similarity was related to the presence of short-lived trophically transmitted parasites, which are associated with their recently consumed food items and, indirectly, to the oceanographic conditions. The same set of host and environmental variables were identified as the most probable causes of the temporal variability observed in parasite assemblages between SPS cohorts and even intra-cohort. Despite the value of parasites as tags for discriminating squid stocks may have little value when cohabiting stocks are analysed, their variability could serve as a valuable indicator of environmental conditions. The use of parasites as biological tags to discriminate stocks needs to be verified at different spatiotemporal scales, including samples from other non-sympatric stocks in the analyses.

3.
R Soc Open Sci ; 11(8): 240797, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39144497

RESUMO

The waters of Greenland harbour a high species richness and biomass of gelatinous zooplankton (GZP); however, their role in the diet of the many fish species, including commercially exploited species, has not yet been verified. Traditionally, GZP was considered to be a trophic dead end, i.e. with a limited contribution as prey for higher trophic levels. We applied DNA metabarcoding of two gene fragments (COI, 18S V1-V2) to the stomach contents of seven pelagic and demersal fish species in Greenland waters, to identify their prey composition as well as the occurrence of GZP predation. We detected GZP DNA reads in the stomachs of all investigated fish species, with frequency of occurrences ranging from 12.5% (for Melanogrammus aeglefinus) to 50% (for Argentina silus). GZP predation had not yet been reported for several of these species. GZP were found to majorly contribute to the diet of A. silus and Anarhichas denticulatus, particularly, the siphonophore Nanomia cara and the scyphozoan Atolla were of a high importance as prey, respectively. The use of multiple genetic markers enabled us to detect a total of 59 GZP taxa in the fish stomachs with several GZP species being detected only by one of the markers.

4.
Parasite ; 31: 50, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39212527

RESUMO

Captive and free-living wildlife serve as significant hosts for Giardia duodenalis. Asiatic black bears, valued for their economic and medicinal importance, are extensively farmed in China and also prevalent in zoos. However, studies on G. duodenalis in these animals in China are limited. Here, 218 feces samples of Asiatic black bears were collected: 36 from a zoo in Heilongjiang Province, and 182 from a farm in Fujian Province. Nested PCR of the SSU rRNA gene, followed by sequencing, was employed to determine the frequency and assemblage distribution of G. duodenalis. Positive samples underwent further analysis through multilocus genotyping (MLG) by amplifying the genes for glutamate dehydrogenase (gdh), ß-giardin (bg), and triosephosphate isomerase (tpi). Of the 218 samples, G. duodenalis was detected in 22 cases at the SSU rRNA gene locus, including three from Heilongjiang and 19 from Fujian. Three assemblages were identified: A (n = 1), B (n = 16), and E (n = 2) in Fujian; and B (n = 3) in Heilongjiang. Out of the 22 positive samples, 20, 19, and 9 were effectively amplified and sequenced across the tpi, gdh, and bg loci, respectively. Seven samples were genotyped successfully at all three loci, identifying MLG-B1 (n = 1), MLG-B2 (n = 1), and MLG-B3 (n = 1), MLG-B4 (n = 1), MLG-B5 (n = 2), and MLG-B6 (n = 1) as the six assemblage B MLGs. This study marks the first documentation of G. duodenalis in Asiatic black bears in captivity in Fujian and Heilongjiang. The identification of zoonotic assemblages A and B, along with E, underscores potential public health concerns.


Title: Prévalence et assemblages de Giardia duodenalis chez les ours noirs d'Asie (Ursus thibetanus) d'élevage et de zoos dans les provinces chinoises du Heilongjiang et du Fujian. Abstract: Les faunes captive et libre incluent des hôtes importants pour Giardia duodenalis. Les ours noirs d'Asie, appréciés pour leur importance économique et médicinale, sont couramment élevés en Chine et répandus dans les zoos. Cependant, les études sur G. duodenalis chez ces animaux en Chine sont limitées. Ici, 218 échantillons d'excréments d'ours noirs d'Asie ont été collectés, 36 dans un zoo de la province du Heilongjiang et 182 dans une ferme de la province du Fujian. La PCR imbriquée de l'ARNr SSU, suivie d'un séquençage, a été utilisée pour déterminer la fréquence et la distribution des assemblages de G. duodenalis. Les échantillons positifs ont subi une analyse plus approfondie par génotypage multilocus (MLG) en amplifiant les gènes de la glutamate déshydrogénase (gdh), de la ß-giardine (bg) et de la triosephosphate isomérase (tpi). Sur les 218 échantillons, G. duodenalis a été détecté dans 22 cas par le locus du gène de l'ARNr SSU, dont trois du Heilongjiang et 19 du Fujian. Trois assemblages ont été identifiés : A (n = 1), B (n = 16) et E (n = 2) dans le Fujian, et B (n = 3) dans le Heilongjiang. Sur les 22 échantillons positifs, 20, 19 et 9 ont été efficacement amplifiés et séquencés respectivement pour les loci tpi, gdh et bg. Sept échantillons ont été génotypés avec succès sur les trois loci, identifiant MLG-B1 (n = 1), MLG-B2 (n = 1) et MLG-B3 (n = 1), MLG-B4 (n = 1), MLG- B5 (n = 2) et MLG-B6 (n = 1) comme les six assemblages MLG B. Cette étude marque la première investigation de G. duodenalis chez les ours noirs d'Asie en captivité au Fujian et au Heilongjiang. L'identification des assemblages zoonotiques A et B, ainsi que E, souligne des problèmes potentiels de santé publique.


Assuntos
Animais de Zoológico , Fezes , Giardia lamblia , Giardíase , Ursidae , Animais , China/epidemiologia , Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Giardia lamblia/classificação , Giardíase/veterinária , Giardíase/parasitologia , Giardíase/epidemiologia , Animais de Zoológico/parasitologia , Prevalência , Ursidae/parasitologia , Fezes/parasitologia , Genótipo , Filogenia , Triose-Fosfato Isomerase/genética , Fazendas , Glutamato Desidrogenase/genética , DNA de Protozoário , Proteínas de Protozoários/genética , Reação em Cadeia da Polimerase/veterinária , Tipagem de Sequências Multilocus , Proteínas do Citoesqueleto/genética
5.
Mar Environ Res ; 200: 106631, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38986234

RESUMO

The use of Artificial substrates (AS) as sampling devices addresses challenges in macrofaunal quantitative sampling. While effectively capturing biodiversity patterns, the time-intensitive identification process at the species level remains a substantial challenge. The Taxonomic Sufficiency approach (TS), where only taxa above species level are identified, arises as a potential solution to be tested across different environmental monitoring scenarios. In this paper, we analyzed three AS macrobenthic datasets to evaluate the odds of TS in improving the cost-effective ratio in AS monitoring studies and establish the highest resolution level to detect assemblage changes under different environmental factors. Results indicated that the family level emerged as a pragmatic compromise, balancing precision and taxonomic effort. Cost/benefit analysis supported TS efficiency, maintaining correlation stability until the family level. Results also showed that reducing resolution to family does not entail a significant Loss of Information. This study contributes to the discourse on TS applicability, highlighting its practicality in monitoring scenarios, including spatial-temporal studies, and rapid biodiversity assessments. Additionally, it highlights the "second best approach" of family-level practicality depending on the specific monitoring scenario and recognizes the importance of the species-level "best approach" before applying TS in monitoring studies.


Assuntos
Biodiversidade , Ecossistema , Monitoramento Ambiental , Monitoramento Ambiental/métodos , Animais , Classificação/métodos , Organismos Aquáticos/fisiologia , Invertebrados/fisiologia
6.
Glob Chang Biol ; 30(7): e17426, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39049564

RESUMO

The ecological impact of non-native species arises from their establishment in local assemblages. However, the rates of non-native spread in new regions and their determinants have not been comprehensively studied. Here, we combined global databases documenting the occurrence of non-native species and residence of non-native birds, mammals, and vascular plants at regional and local scales to describe how the likelihood of non-native occurrence and their proportion in local assemblages relate with their residence time and levels of human usage in different ecosystems. Our findings reveal that local non-native occurrence generally increases with residence time. Colonization is most rapid in croplands and urban areas, while it is slower and variable in natural or semi-natural ecosystems. Notably, non-native occurrence continues to rise even 200 years after introduction, especially for birds and vascular plants, and in other land-use types rather than croplands and urban areas. The impact of residence time on non-native proportions is significant only for mammals. We conclude that the continental exchange of biotas requires considerable time for effects to manifest at the local scale across taxa and land-use types. The unpredictability of future impacts, implied by the slow spread of non-native species, strengthens the call for stronger regulations on the exchange of non-native species to reduce the long-lasting invasion debt looming on ecosystems' future.


Assuntos
Aves , Espécies Introduzidas , Mamíferos , Animais , Plantas , Ecossistema , Biodiversidade , Conservação dos Recursos Naturais
7.
Sociol Health Illn ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965749

RESUMO

The use of restrictive practices within health and social care has attracted policy and practice attention, predominantly focusing on children and young people with mental health conditions, learning disabilities and autism. However, despite growing appreciation of the need to improve care quality for people living with dementia (PLWD), the potentially routine use of restrictive practices in their care has received little attention. PLWD are at significant risk of experiencing restrictive practices during unscheduled acute hospital admissions. In everyday routine hospital care of PLWD, concerns about subtle and less visible forms of restrictive practices and their impacts remain. This article draws on Deleuze's concepts of 'assemblage' and 'event' to conceptualise restrictive practices as institutional, interconnection social and political attitudes and organisational cultural practices. We argue that this approach illuminates the diverse ways restrictive practices are used, legitimatised and perpetuated in the care of PLWD. We examine restrictive practices in acute care contexts, understanding their use requires examining the wider socio-political, organisational cultures and professional practice contexts in which clinical practices occurs. Whereas 'events' and 'assemblages' have predominantly been used to examine embodied entanglements in diverse health contexts, examining restrictive practices as a structural assemblage extends the application of this theoretical framework.

8.
Glob Chang Biol ; 30(7): e17421, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39034889

RESUMO

Current knowledge about the impacts of urbanisation on bird assemblages is based on evidence from studies partly or wholly undertaken in the breeding season. In comparison, the non-breeding season remains little studied, despite the fact that winter conditions at higher latitudes are changing more rapidly than other seasons. During the non-breeding season, cities may attract or retain bird species because they offer milder conditions or better feeding opportunities than surrounding habitats. However, the range of climatic, ecological and anthropogenic mechanisms shaping different facets of urban bird diversity in the non-breeding season are poorly understood. We explored these mechanisms using structural equation modelling to assess how urbanisation affects the taxonomic, phylogenetic and functional diversity of avian assemblages sampled worldwide in the non-breeding season. We found that minimum temperature, elevation, urban area and city age played a critical role in determining taxonomic diversity while a range of factors-including productivity, precipitation, elevation, distance to coasts and rivers, socio-economic (as a proxy of human facilitation) and road density-each contributed to patterns of phylogenetic and functional diversity. The structure and function of urban bird assemblages appear to be predominantly shaped by temperature, productivity and city age, with effects of these factors differing across seasons. Our results underline the importance of considering multiple hypotheses, including seasonal effects, when evaluating the impacts of urbanisation on biodiversity.


Assuntos
Biodiversidade , Aves , Cidades , Estações do Ano , Urbanização , Animais , Aves/fisiologia , Filogenia
9.
Sci Total Environ ; 946: 174148, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38906285

RESUMO

Environmental DNA (eDNA) analysis has now become a core approach in marine biodiversity research, which typically involves the collection of water or sediment samples. Yet, recently, filter-feeding organisms have received much attention for their potential role as natural eDNA samplers. While the indiscriminate use of living organisms as 'sampling tools' might in some cases raise conservation concerns, there are instances in which highly abundant sessile organisms may become a nuisance as biofouling on artificial marine structures. Here we demonstrate how a sea sponge species that colonizes the moorings of the world's largest curtain of hydroacoustic receivers can become a powerful natural collector of fish biodiversity information. By sequencing eDNA extracted from Vazella pourtalesii retrieved from moorings during routine biofouling maintenance, we detected 23 species of marine fish and mammals, compared to 19 and 15 species revealed by surface and bottom water eDNA respectively, and 28 species captured by groundfish survey in the surrounding area, which are more ecologically impactful and involve higher additional costs. Sponge-based species inventories proved at least as informative as those obtained by traditional survey methods, and are also able to detect seasonal differences in fish assemblages. We conclude that opportunistic sampling of marine sponge biofouling may become an efficient way to document and monitor biodiversity in our rapidly changing oceans.


Assuntos
Biodiversidade , Incrustação Biológica , DNA Ambiental , Monitoramento Ambiental , Poríferos , Animais , Monitoramento Ambiental/métodos , DNA Ambiental/análise , Organismos Aquáticos/genética , Peixes
10.
Ecol Appl ; 34(5): e2964, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38842210

RESUMO

Scientists increasingly draw on fishers' ecological knowledge (FEK) to gain a better understanding of fish biology and ecology, and inform options for fisheries management. We report on a study of FEK among fishers along the Lower Ucayali River in Peru, a region of exceptional productivity and diversity, which is also a major supplier of fish to the largest city in the Peruvian Amazon. Given a lack of available scientific information on stock status, we sought to identify temporal changes in the composition and size of exploited species by interviewing fishers from 18 communities who vary in years of fishing experience since the mid-1950s. We develop four FEK-based indicators to assess changes in the fish assemblage and compare findings with landings data. We find an intensification of fishing gear deployed over time and spatiotemporal shifts in the fish assemblage and reported declines in species weight, which point to a fishing-down process with declines across multiple species. This finding is reflected in a shifting baseline among our participants, whereby younger generations of fishers have different expectations regarding the distribution and size of species. Our study points to the importance of spillover effects from the nearby Pacaya-Samira National Reserve and community initiatives to support the regional fishery. Reference to fishers' knowledge also suggests that species decline is likely underreported in aggregated landings data. Despite the dynamism and diversity of Amazonian floodplain fisheries, simple FEK-based indicators can provide useful information for understanding fishing-induced changes in the fish assemblage. Fishers hold valuable knowledge for fishery management and conservation initiatives in the region.


Assuntos
Pesqueiros , Peixes , Peru , Animais , Peixes/fisiologia , Humanos , Conservação dos Recursos Naturais/métodos , Fatores de Tempo , Rios
11.
Vet Parasitol Reg Stud Reports ; 52: 101042, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38880565

RESUMO

Giardiasis is a small intestinal disease caused by the zoonotic parasite, Giardia duodenalis. This study presents the molecular findings of G. duodenalis infection in companion dogs, domestic livestock and wildlife in the Northern Jordan Basin, Israel. Identification of G. duodenalis was accomplished by nested PCR (nPCR) targeting the 18S rRNA gene. Samples were collected from water (five samples from four sources of which one was recycled water), as well as feces from wolves (Canis lupus) (n = 34), jackals (Canis aureus) (n = 24), wild boars (Sus scrofa) (n = 40), cattle (Bos taurus) (n = 40), dogs (Canis lupus familiaris) (n = 37) and nutria (Mayocastor coypus) (n = 100). All positive samples were sequenced and a phylogenetic tree was drawn using the Bayesian Inference (BI) algorithm. Differences in G. duodenalis prevalence between the different hosts were analyzed by Pearson's chi-square (p < 0.05). Of the total 275 fecal samples, 36 were positive for G. duodenalis (13%). Frequency rates among different animal species was highest in wolves (32.3%), whilst rates in wild boars (22.5%), dogs (16.2%), cattle (12.5%) and jackals (4.2%), were observed to be significantly lower (p < 0.001). Three out of 5 recycled water (RW) samples were G. duodenalis positive. Three clusters with high posterior probabilities (PP) were found in the BI: Cluster 1: samples from wolves, wild boars, water and cattle together with database sequences of assemblages A, B and F, Cluster 2: samples from dogs, nutria and a jackal with sequences from assemblage D and Cluster 3: samples from cattle, wild boars, wolves and dogs with sequences from assemblage C and D. We suggest that wolves serve as reservoirs of G. duodenalis in this region. The finding of Giardia in RW suggests that this vehicle may further contaminate crops intended for human consumption as this water source is used for agricultural irrigation.


Assuntos
Animais Selvagens , Doenças do Cão , Fezes , Giardia lamblia , Giardíase , Filogenia , Animais , Cães , Giardíase/veterinária , Giardíase/epidemiologia , Giardíase/parasitologia , Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Giardia lamblia/classificação , Prevalência , Fezes/parasitologia , Doenças do Cão/parasitologia , Doenças do Cão/epidemiologia , Israel/epidemiologia , Animais Selvagens/parasitologia , Gado/parasitologia , RNA Ribossômico 18S/análise , RNA Ribossômico 18S/genética , Bovinos , Reação em Cadeia da Polimerase/veterinária , Animais de Estimação/parasitologia
12.
Mar Environ Res ; 199: 106623, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38917660

RESUMO

Marine phytoplankton are widely used to monitor the state of the water column due to their rapid changes in response to environmental conditions. In this study, we aimed to investigate the coastal phytoplankton assemblages, including bloom-forming species using high-throughput sequencing of 18S rRNA genes targeting the V4 region and their relationship with environmental variables along the Istanbul coasts of the Sea of Marmara. A total of 118 genera belonging to six phyla were detected. Among them, Dinoflagellata (36) and Bacillariophyta (26) were represented with the highest number of genera. According to the relative abundance of DNA reads, the most abundant taxa were Dinoflagellata_phylum (18.1%), Emiliania (8.4%), Biecheleria (8.4), and Noctiluca (8.1%). The ANOSIM test showed that there was a significant temporal difference in the assemblages, while the driving environmental factors were pH, water temperature, and salinity. According to the TRIX index, the trophic state of the coasts was highly mesotrophic and eutrophic. In addition, 45 bloom-forming and HAB taxa were detected and two species of Noctiluca and Emiliania, which frequently cause blooms in the area, were recorded in high abundance. Our results provide insight into the phytoplankton assemblages along the urbanized coastlines by analysing the V4 region of 18S rRNA. This data can support future studies that use both traditional methods and metabarcoding, employing various primers and targeting different genes and regions.


Assuntos
Código de Barras de DNA Taxonômico , Monitoramento Ambiental , Fitoplâncton , Fitoplâncton/genética , Monitoramento Ambiental/métodos , Turquia , RNA Ribossômico 18S/genética , DNA Ambiental/genética , DNA Ambiental/análise , Proliferação Nociva de Algas , Dinoflagellida/genética , Biodiversidade
13.
Vet Parasitol ; 329: 110192, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38749124

RESUMO

Giardia duodenalis (syn. G. intestinalis or G. lamblia) is a parasitic protozoan that infects the upper intestinal tract of a broad range of hosts, including humans and domestic animals. Thus, it has raised concerns about the public health risk due to companion animals. Recently, with the improvement of living standards and increasing contacts between pets and humans, the zoonotic transmission of Giardia has dramatically increased. From a genetic point of view, G. duodenalis should be viewed as a complex species that includes eight different species-specific genetic assemblages. The laboratory diagnosis is mainly based on the finding of microscopic cysts in stool samples by coprological examination. Other methods include the detection of antigens, immunoassays or PCR protocols, which allow the identification of Giardia assemblages. The study aimed to compare the performance of Direct Fluorescence Antibody test (DFA), zinc sulfate flotation technique (ZnSO4), rapid diagnostic test (RDT), end-point PCR amplification (PCR) for the detection of Giardia and to identify the concerning assemblages in a canine population from Central Italy. Direct fluorescence antibody test is the reference standard for laboratory diagnosis of Giardia in fecal samples from dogs, despite the microscopic examination after flotation remains the most useful method in many veterinary diagnostic centers. The present findings demonstrate the high performance of DFA and ZnSO4 in detecting Giardia, while RDT may be useful as alternative or complementary method to the DFA and ZnSO4. PCR performance was low, but it allowed determining Giardia B zoonotic assemblage in 25% of the PCR-positive specimens (15 out of 60), while the remaining PCR-positive isolates belonged to the dog-specific assemblage C. The 26% prevalence of G. duodenalis detected by DFA in owned dogs and the identification of potentially zoonotic assemblages underline the potential risk for public health and indicate frequent cross-species transmission of the parasite between humans and dogs.


Assuntos
Doenças do Cão , Fezes , Giardíase , Zoonoses , Animais , Cães , Giardíase/veterinária , Giardíase/diagnóstico , Giardíase/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Zoonoses/diagnóstico , Zoonoses/parasitologia , Fezes/parasitologia , Humanos , Reação em Cadeia da Polimerase/veterinária , Reação em Cadeia da Polimerase/métodos , Giardia/isolamento & purificação , Giardia/genética , Giardia lamblia/isolamento & purificação , Giardia lamblia/genética , Técnica Direta de Fluorescência para Anticorpo/veterinária , Itália/epidemiologia , Sensibilidade e Especificidade
14.
Int J Parasitol Parasites Wildl ; 24: 100938, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38699516

RESUMO

A total of 333 vials of nematodes collected from three species of Isoodon (representing three individuals of I. auratus, 63 of I. fusciventer and 92 of I. obesulus) held in the Australian Helminthological Collection of the South Australian Museum were examined. Nematodes were identified and the nematode assemblages of the three hosts were compared with each other and with the assemblage of Isoodon macrourus. Two fully identified species were recovered from I. auratus, eight from I. fusciventer and 14 from I. obesulus. None of the species occurred in all three hosts; Labiobulura inglisi (Subuluridae), Peramelistrongylus skedastos (Dromaeostrongylidae) and Asymmetracantha tasmaniensis (Mackerrastrongylidae) all occurred in I. fusciventer and I. obesulus. Only Pe. skedastos was also found in I. macrourus. Sorensen's index of similarity, 27.2 %, showed that I. fusciventer and I. obesulus did not have similar nematode communities and neither were their communities similar to that of I. macrourus, 17.1 % and 39.0 % respectively. Labiobulura inglisi and Linstowinema inglisi were the dominant nematodes in the assemblage of I. fusciventer and La. inglisi was dominant in I. obesulus. The two hosts had nematode assemblages with unique species profiles; one species of Linstowinema in I. fusciventer, three in I. obesulus; a species of Physaloptera in I. obesulus, none in I. fusciventer; four species of strongylid; Asymmetracantha tasmaniensis the most prevalent in I. fusciventer, Peramelistrongylus skedastos the most prevalent in I.obesulus. The size of the geographic range is a probable determinant of the species richness of the nematode assemblages.

15.
Glob Chang Biol ; 30(4): e17282, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38619685

RESUMO

Given the current environmental crisis, biodiversity protection is one of the most urgent socio-environmental priorities. However, the effectiveness of protected areas (PAs), the primary strategy for safeguarding ecosystems, is challenged by global climate change (GCC), with evidence showing that species are shifting their distributions into new areas, causing novel species assemblages. Therefore, there is a need to evaluate PAs' present and future effectiveness for biodiversity under the GCC. Here, we analyzed changes in the spatiotemporal patterns of taxonomic and phylogenetic diversity (PD) of plants associated with the Neotropical seasonally dry forest (NSDF) under GCC scenarios. We modeled the climatic niche of over 1000 plant species in five representative families (in terms of abundance, dominance, and endemism) of the NSDF. We predicted their potential distributions in the present and future years (2040, 2060, and 2080) based on an intermediate scenario of shared socio-economic pathways (SSP 3.70), allowing species to disperse to new sites or constrained to the current distribution. Then, we tested if the current PAs network represents the taxonomic and phylogenetic diversities. Our results suggest that GCC could promote novel species assemblages with local responses (communities' modifications) across the biome. In general, models predicted losses in the taxonomic and phylogenetic diversities of all the five plant families analyzed across the distribution of the NSDF. However, in the northern floristic groups (i.e., Antilles and Mesoamerica) of the NSDF, taxonomic and PD will be stable in GCC projections. In contrast, across the NSDF in South America, some cores will lose diversity while others will gain diversity under GCC scenarios. PAs in some NSDF regions appeared insufficient to protect the NSDF diversity. Thus, there is an urgent need to assess how the PA system could be better reconfigured to warrant the protection of the NSDF.


Dada la actual crisis ambiental, la protección de la biodiversidad se presenta como una de las prioridades socio ambientales más urgentes. Sin embargo, la efectividad de las áreas protegidas (AP), la estrategia principal para salvaguardar los ecosistemas, se ve desafiada por el cambio climático global (CCG), con evidencia que muestra que las especies están desplazando sus distribuciones hacia nuevas áreas, provocando conjuntos de especies novedosos. Por lo tanto, es necesario evaluar la efectividad actual y futura de las AP para la biodiversidad bajo el CCG. En este contexto, analizamos cambios en los patrones espacio­temporales de diversidad taxonómica y filogenética de plantas asociadas al bosque estacionalmente seco neotropical (BES) bajo escenarios de CCG. Modelamos el nicho climático de más de 1,000 especies de plantas en cinco familias representativas (en términos de abundancia, dominancia y endemismo) del BES. Pronosticamos sus distribuciones potenciales en los años actuales y futuros (2040, 2060 y 2080) basándonos en un escenario intermedio de trayectorias socioeconómicas compartidas (SSP 3.70), permitiendo que las especies se dispersen a nuevos sitios o estén limitadas a la distribución actual. Luego, evaluamos si la red actual de AP representa las diversidades taxonómicas y filogenéticas. Nuestros resultados sugieren que el CCG podría promover conjuntos de especies novedosos con respuestas locales (modificaciones en las comunidades) en todo el bioma. En general, los modelos pronosticaron pérdidas en las diversidades taxonómicas y filogenéticas de las cinco familias de plantas analizadas en la distribución del BES. Sin embargo, en los grupos florísticos del norte (es decir, Antillas y Mesoamérica) del BSDN, la diversidad taxonómica y filogenética se mantendrá estable en las proyecciones de CCG. En cambio, en toda la región del BES en América del Sur, algunos núcleos perderán diversidad mientras que otros ganarán diversidad bajo escenarios de CCG. Algunas AP en regiones del BES parecen ser insuficientes para proteger la diversidad del bioma. Por lo tanto, es urgente evaluar cómo se podría reconfigurar mejor el sistema de AP para garantizar la protección del BES.


Assuntos
Ecossistema , Florestas , Filogenia , Biodiversidade , Mudança Climática
16.
Iran J Parasitol ; 19(1): 98-104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38654947

RESUMO

Background: We aimed to investigate the molecular genotyping of Giardia duodenalis in Humans in the Yazd County, Central, Iran. Methods: Total of 35 fecal samples were collected from patients referred to Yazd Central Laboratory, Yazd, Iran from February to July 2022. All the samples were included in this study after microscopic observation of G. duodenalis. DNA samples were extracted using related kit and were analyzed by Nano Drop. The molecular assessment was carried out using semi-nested PCR using the target gene of gdh. All amplified samples were sequenced using Sanger method. BLAST analyzed the sequences for assemblage identification. Results: Out of 35 samples, 24 (68.57%) and 11 (31.43%) were male and female, respectively. All included samples were amplified using the specific gdh primer pair. The molecular analysis showed 17 isolates (48.57%) as assemblage BIV, 8 isolates (22.86%) as assemblage BIII, 6 isolates (17.14%) as assemblage AII and 4 isolates (11.43%) as assemblage AIII (P<0.05). Conclusion: Assemblages A and B are the most prevalent in Central Iran. The molecular identification of G. duodenalis isolates from animals and implementing control programs.

17.
J Hazard Mater ; 471: 134342, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678705

RESUMO

The accumulation of microplastics in reservoirs due to river damming has drawn considerable attention due to their potential impacts on elemental biogeochemical cycling at the watershed scale. However, the effects of plastisphere communities on the sulfur cycle in the large deep-water reservoir remain poorly understood. Here, we collected microplastics and their surrounding environmental samples in the water and sediment ecosystems of Xiaowan Reservoir and found a significant spatiotemporal pattern of microplastics and sulfur distribution in this Reservoir. Based on the microbial analysis, plastic-degrading taxa (e.g., Ralstonia, Rhodococcus) involved in the sulfur cycle were enriched in the plastisphere of water and sediment, respectively. Typical thiosulfate oxidizing bacteria Limnobacter acted as keystone species in the plastisphere microbial network. Sulfate, oxidation reduction potential and organic matter drove the variations of the plastisphere. Environmental filtration significantly affected the plastisphere communities, and the deterministic process dominated the community assembly. Furthermore, predicted functional profiles related to sulfur cycling, compound degradation and membrane transport were significantly enriched in the plastisphere. Overall, our results suggest microplastics as a new microbial niche exert different effects in water and sediment environments, and provide insights into the potential impacts of the plastisphere on the sulfur biogeochemical cycle in the reservoir ecosystem.


Assuntos
Sedimentos Geológicos , Microplásticos , Enxofre , Poluentes Químicos da Água , Enxofre/metabolismo , Microplásticos/metabolismo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/análise , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Bactérias/metabolismo , Bactérias/classificação , China
18.
Mar Environ Res ; 197: 106468, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537361

RESUMO

Chondrichthyans (sharks, rays, and chimaeras) are highly susceptible to the impacts of fisheries due to their vulnerable life-history traits. Over the last 100 years, several cases of local extinction have been documented in heavily fished areas across the Mediterranean Sea. In the Strait of Sicily (SoS), one of the main demersal fishing grounds of the Mediterranean, chondrichthyans constitute a significant component of both commercial and discarded bycatch. In this area, the lack of long-term data series on these species hinders our ability to fully comprehend the extent of changes due to both overfishing and climate variations. Here we aim to use historical data from the end of the 19th century, provided by Döderlein, to uncover evidence of long-term changes in the occurrence and diversity of these fishes. We employ a semi-quantitative approach to compare past data with recent frequency of occurrence estimates, to improve our ability to propose management advice. We report a decline in both the number of species and the frequency of occurrence of sharks and ray species in the study region over the past 150 years. Our findings shed light on the current status of sharks and rays compared to the historical data from the 19th century and highlight the urgent need to develop management strategies to mitigate the impact of harvesting on these vulnerable species.


Assuntos
Conservação dos Recursos Naturais , Tubarões , Animais , Pesqueiros , Mar Mediterrâneo , Clima , Ecossistema
19.
Insects ; 15(3)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38535344

RESUMO

The Toce River (Northern Italy) is characterized by legacy contamination of dichloro-diphenyl-trichloroethane (DDT), mercury, and arsenic deriving from an industrial plant active between ca. 1915 and 1996. Chironomidae taxa assemblages and sediments were collected in 2014 and 2019 upstream and downstream of the industrial area to analyze species responses to toxic substances in a river stretch with relatively uniform natural (i.e., hydro-morphological) characteristics. A total of 32 chironomid taxa were identified. Sediment concentrations reached levels potentially toxic for benthic invertebrates: 15.7 µg kg-1 1% organic carbon for DDT, 197 µg kg-1 dry weight (d.w.) for Hg, and 55.7 mg kg-1 d.w. for As. Canonical Correspondence Analysis (CCA) revealed a predominant seasonal gradient, followed by an upstream-downstream gradient. Partial CCA indicated that 5.2% of the total variation was associated with sediment contamination. Self-Organizing Maps (SOMs) were used to represent species responses to toxicants. Most species appeared to be tolerant, e.g., Chironomus riparius, Micropsectra atrofasciata, Conchapelopia pallidula, and Polypedilum spp. Sensitivity to contaminants was observed in only a few species: Diamesa spp., Sympotthastia spinifera, and Prodiamesa olivacea to DDT; Potthastia longimanus to Hg; Odontomesa fulva and Microtendipes pedellus to As. The chironomid community was characterized in presence of contamination levels commonly observed in freshwater ecosystems.

20.
Ecol Evol ; 14(2): e10947, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38357589

RESUMO

Understory assemblages associated with canopy-forming species such as trees, kelps, and rockweeds should respond strongly to climate stressors due to strong canopy-understory interactions. Climate change can directly and indirectly modify these assemblages, particularly during more stressful seasons and climate scenarios. However, fully understanding the seasonal impacts of different climate conditions on canopy-reliant assemblages is difficult due to a continued emphasis on studying single-species responses to a single future climate scenario during a single season. To examine these emergent effects, we used mesocosm experiments to expose seaweed assemblages associated with the canopy-forming golden rockweed, Silvetia compressa, to elevated temperature and pCO2 conditions reflecting two projected greenhouse emission scenarios (RCP 2.6 [low] & RCP 4.5 [moderate]). Assemblages were grown in the presence and absence of Silvetia, and in two seasons. Relative to ambient conditions, predicted climate scenarios generally suppressed Silvetia biomass and photosynthetic efficiency. However, these effects varied seasonally-both future scenarios reduced Silvetia biomass in summer, but only the moderate scenario did so in winter. These reductions shifted the assemblage, with more extreme shifts occurring in summer. Contrarily, future scenarios did not shift assemblages within Silvetia Absent treatments, suggesting that climate primarily affected assemblages indirectly through changes in Silvetia. Mesocosm experiments were coupled with a field Silvetia removal experiment to simulate the effects of climate-mediated Silvetia loss on natural assemblages. Consistent with the mesocosm experiment, Silvetia loss resulted in season-specific assemblage shifts, with weaker effects observed in winter. Together, our study supports the hypotheses that climate-mediated changes to canopy-forming species can indirectly affect the associated assemblage, and that these effects vary seasonally. Such seasonality is important to consider as it may provide periods of recovery when conditions are less stressful, especially if we can reduce the severity of future climate scenarios.

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