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1.
Proc Biol Sci ; 291(2026): 20241214, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38981524

RESUMO

Obligatory ant-plant symbioses often appear to be single evolutionary shifts within particular ant lineages; however, convergence can be revealed once natural history observations are complemented with molecular phylogenetics. Here, we describe a remarkable example of convergent evolution in an ant-plant symbiotic system. Exclusively arboreal, Myrmelachista species can be generalized opportunists nesting in several plant species or obligately symbiotic, live-stem nesters of a narrow set of plant species. Instances of specialization within Myrmelachista are known from northern South America and throughout Middle America. In Middle America, a diverse radiation of specialists occupies understory treelets of lowland rainforests. The morphological and behavioural uniformity of specialists suggests that they form a monophyletic assemblage, diversifying after a single origin of specialization. Using ultraconserved element phylogenomics and ancestral state reconstructions, we show that shifts from opportunistic to obligately symbiotic evolved independently in South and Middle America. Furthermore, our analyses support a remarkable case of convergence within the Middle American radiation, with two independently evolved specialist clades, arising nearly simultaneously from putative opportunistic ancestors during the late Pliocene. This repeated evolution of a complex phenotype suggests similar mechanisms behind trait shifts from opportunists to specialists, generating further questions about the selective forces driving specialization.


Assuntos
Formigas , Evolução Biológica , Filogenia , Simbiose , Formigas/fisiologia , Formigas/genética , Animais , América do Sul , América Central , Mirmecófitas
2.
Nat Commun ; 15(1): 6045, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39025837

RESUMO

Climate change is conjectured to endanger tropical species, particularly in biodiverse montane regions, but accurate estimates of extinction risk are limited by a lack of empirical data demonstrating tropical species' sensitivity to climate. To fill this gap, studies could match high-quality distribution data with multi-year transplant experiments. Here, we conduct field surveys of epiphyte distributions on three mountains in Central America and perform reciprocal transplant experiments on one mountain across sites that varied in elevation, temperature and aridity. We find that most species are unable to survive outside of their narrow elevational distributions. Additionally, our findings suggest starkly different outcomes from temperature conditions expected by 2100 under different climate change scenarios. Under temperatures associated with low-emission scenarios, most tropical montane epiphyte species will survive, but under emission scenarios that are moderately high, 5-36% of our study species may go extinct and 10-55% of populations may be lost. Using a test of tropical species' climate tolerances from a large field experiment, paired with detailed species distribution data across multiple mountains, our work strengthens earlier conjecture about risks of wide-spread extinctions from climate change in tropical montane ecosystems.


Assuntos
Mudança Climática , Ecossistema , Extinção Biológica , Clima Tropical , Temperatura , América Central , Altitude , Plantas
4.
Appetite ; 200: 107549, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38862079

RESUMO

BACKGROUND: The food choices of migrants are frequently limited by lack of access to sufficient and adequate food. Food insecurity (FI) during adolescence has potential negative health consequences, however the experiences of FI of adolescent in-transit migrants have seldom been reported. OBJECTIVE: To explore the experiences of FI of adolescent in-transit migrants and their ways of coping with it. METHODS: Qualitative study, with 19 semi-structured interviews with adolescents (ages 13-19 years), in shelters for migrants in Mexico in 2022-2023. We followed a reflexive thematic analysis strategy. RESULTS: Most participants had experienced FI during the journey, and responded by limiting intake, choosing food according to price, seeking temporary work or asking for food or money in the streets. We defined "solidarity through food" as a central theme that summarized participants' experiences of sharing food with other migrants, as givers or recipients. Solidarity through food was a response to FI, benefitting the more disadvantaged (e.g. young children, those who had been robbed). Despite their young age, interviewees took part in this, giving their food to others and restricting their intake to prioritize younger siblings. DISCUSSION/CONCLUSIONS: Solidarity through food was a form of generalized reciprocity, enacted not only among family members or friends, but extended to other migrants sharing the route. In further studies, it will be important to explore the role and nuances of food sharing as a practice of social exchange of responsibility and care, on adolescent migrants' health, and in their psychological and relational development into adulthood.


Assuntos
Insegurança Alimentar , Pesquisa Qualitativa , Migrantes , Humanos , Adolescente , México , Feminino , Masculino , Migrantes/psicologia , Adulto Jovem , América Central/etnologia , Adaptação Psicológica , Abastecimento de Alimentos
5.
Parasitol Int ; 102: 102916, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38936764

RESUMO

A new genus, Cordicestus, is proposed to accommodate proteocephalid tapeworms parasitising gars (Lepisosteiformes: Lepisosteidae) in North and Central America that were previously placed in the polyphyletic genus Proteocephalus Weinland, 1858. The new genus differs from other proteocephalid genera by the particular morphology of the scolex, which is small, protrudes apically but has no apical organ, and bears flat, heart-shaped (= cordis) suckers. In addition, the species of the new genus have an elongated cirrus sac with an almost straight internal vas deferens and wide, sinuous ventral osmoregulatory canals with secondary canals directed outwards. The type species of the new genus, Cordicestus singularis (La Rue, 1911) n. comb., is redescribed based on new material from the shortnose gar, Lepisosteus platostomus Rafinesque (type host), and the spotted gar, L. oculatus Winchell, in the United States. Cordicestus rafaeli n. sp. is described from the tropical gar, Atractosteus tropicus Gill, in Mexico. The new species differs from its relatives primarily by the presence of craspedote proglottids (acraspedote in other species) and some biometric features. All species of Cordicestus are revised, including unidentified specimens from A. tropicus and the Cuban gar A. tristoechus (Bloch and Schneider) in Nicaragua and Cuba, respectively, which may be new species, and a key to the identification of these taxa is provided. Molecular data available for two nominal species of the new genus indicate the possible existence of another species of Cordicestus in Lepisosteus in the USA.


Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Peixes , Peixes , Animais , Cestoides/classificação , Cestoides/anatomia & histologia , Cestoides/isolamento & purificação , Doenças dos Peixes/parasitologia , Infecções por Cestoides/veterinária , Infecções por Cestoides/parasitologia , Peixes/parasitologia , Fósseis , Estados Unidos , América Central , Filogenia
6.
Nat Commun ; 15(1): 4278, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778039

RESUMO

Toxoplasma gondii is a global protozoan pathogen. Clonal lineages predominate in Europe, North America, Africa, and China, whereas highly recombinant parasites are endemic in South/Central America. Far East Asian T. gondii isolates are not included in current global population genetic structure analyses at WGS resolution. Here we report a genome-wide population study that compared eight Japanese and two Chinese isolates against representative worldwide T. gondii genomes using POPSICLE, a novel population structure analyzing software. Also included were 7 genomes resurrected from non-viable isolates by target enrichment sequencing. Visualization of the genome structure by POPSICLE shows a mixture of Chinese haplogroup (HG) 13 haploblocks introgressed within the genomes of Japanese HG2 and North American HG12. Furthermore, two ancestral lineages were identified in the Japanese strains; one lineage shares a common ancestor with HG11 found in both Japanese strains and North American HG12. The other ancestral lineage, found in T. gondii isolates from a small island in Japan, is admixed with genetically diversified South/Central American strains. Taken together, this study suggests multiple ancestral links between Far East Asian and American T. gondii strains and provides insight into the transmission history of this cosmopolitan organism.


Assuntos
Genoma de Protozoário , Filogenia , Toxoplasma , Toxoplasma/genética , Toxoplasma/classificação , Humanos , América do Norte , Genoma de Protozoário/genética , Toxoplasmose/parasitologia , China , América Central , Japão , Haplótipos , Variação Genética , Recombinação Genética
7.
PeerJ ; 12: e17242, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38699180

RESUMO

Kiekie Polotow & Brescovit, 2018 is a Neotropical genus of Ctenidae, with most of its species occuring in Central America. In this study, we review the systematics of Kiekie and describe five new species and the unknown females of K. barrocolorado Polotow & Brescovit, 2018 and K. garifuna Polotow & Brescovit, 2018, and the unknown male of K. verbena Polotow & Brescovit, 2018. In addition, we described the female of K. montanense which was wrongly assigned as K. griswoldi Polotow & Brescovit, 2018 (both species are sympatric). We provided a modified diagnosis for previously described species based on the morphology of the newly discovered species and in situ photographs of living specimens. We inferred a molecular phylogeny using four nuclear (histone H3, 28S rRNA, 18S rRNA and ITS-2) and three mitochondrial genes (cytochrome c oxidase subunit I or COI, 12S rRNA and 16S rRNA) to test the monophyly of the genus and the evolutionary relationships of its species. Lastly, we reconstruct the historical biogeography and map diversity and endemism distributional patterns of the different species. This study increased the number of known species of Kiekie from 13 to 18, and we describe a new genus, Eldivo which is sister lineage of Kiekie. Most of the diversity and endemism of the genus Kiekie is located in the montane ecosystems of Costa Rica followed by the lowland rainforest of the Pacific side (Limon Basin). Kiekie originated in the North America Tropical region, this genus started diversifying in the Late Miocene and spread to Lower Central America and South America. In that region, Kiekie colonized independently several times the montane ecosystems corresponding to periods of uplifting of Talamanca and Central Cordilleras.


Assuntos
Filogenia , Aranhas , Animais , Aranhas/classificação , Aranhas/genética , América Central , Feminino , Masculino , Distribuição Animal , Filogeografia
8.
J Fish Biol ; 105(1): 314-325, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38757464

RESUMO

Phylogenetic analyses of mitochondrial and nuclear data of 31 specimens of Cyphocharax from trans-Andean rivers support the presence of one lineage of Cyphocharax aspilos in Lago Maracaibo and three cryptic lineages of Cyphocharax magdalenae: (1) Cauca-Magdalena and Ranchería, (2) León and Atrato, and (3) Chucunaque-Tuira, Santa María, and Chiriquí basins of Central America. Results suggest that the Serranía del Perijá facilitated Late Miocene cladogenetic events, whereas post-Isthmian C. magdalenae expansion was enabled by gene flow across the lower Magdalena valley and Central American lowlands. Time-calibrated phylogenetics indicate that the C. magdalenae colonized lower Central America in the Pliocene (3.7 MYA; Ma), the divergence Atrato-Magdalena occurred in Late Pliocene (3.0 Ma) and the split Ranchería-Magdalena during the Middle Pleistocene (1.3 Ma). Updated geographic distribution data support the hypothesis that the Cordillera de Talamanca functions as a barrier to northward expansion of C. magdalenae in Central America.


Assuntos
Filogenia , Filogeografia , Rios , Animais , América Central , DNA Mitocondrial/genética , Fluxo Gênico , Núcleo Celular/genética , Análise de Sequência de DNA
9.
PLoS One ; 19(5): e0304756, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38820545

RESUMO

Climate adaptation corridors are widely recognized as important for promoting biodiversity resilience under climate change. Central America is part of the Mesoamerican biodiversity hotspot, but there have been no regional-scale analyses of potential climate adaptation corridors in Central America. We identified 2375 potential corridors throughout Central America that link lowland protected areas (≤ 500 m) with intact, high-elevation forests (≥ 1500 m) that represent potential climate change refugia. Whereas we found potential corridors in all Central American countries, potential corridors in Panama, Belize, and Honduras were most protected (medians = 64%, 49%, and 47%, respectively) and potential corridors in El Salvador were least protected (median = 10%). We also developed a corridor priority index based on the ecological characteristics and protected status of potential corridors and their associated start and end points. Compared to low- and medium-priority corridors, high-priority corridors (n = 160; top 7% of all corridors) were generally more protected, forested, and distributed across wider elevational gradients and more Key Biodiversity Areas, but also generally linked larger lowland protected areas to target areas that were larger, more protected, and spanned wider elevational gradients. For example, based on median values, high-priority corridors were 9% more protected and overlapped with 2-3 more Key Biodiversity Areas than low- and medium-priority corridors. Although high-elevation targets spanned considerably wider elevational gradients than lowland protected areas (medians = 695 vs. 142 m, respectively) and thus may be more likely to support refugia, they were considerably smaller than lowland protected areas (medians = 11 vs. 50 km2 respectively) and mostly unprotected (median = 4% protection). This initial, regional assessment can help prioritize locations for finer-scale research, conservation, and restoration activities in support of climate adaptation corridors throughout Central America and highlights the need for greater conservation of potential high-elevation refugia.


Assuntos
Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais , América Central , Florestas , Refúgio de Vida Selvagem
11.
Sci Data ; 11(1): 349, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589396

RESUMO

The Caribbean & Mesoamerica Biogeochemical Isotope Overview (CAMBIO) is an archaeological data community designed to integrate published biogeochemical data from the Caribbean, Mesoamerica, and southern Central America to address questions about dynamic interactions among humans, animals, and the environment in the region over the past 10,000 years. Here we present the CAMBIO human dataset, which consists of more than 16,000 isotopic measurements from human skeletal tissue samples (δ13C, δ15N, δ34S, δ18O, 87Sr/86Sr, 206/204Pb, 207/204Pb, 208/204Pb, 207/206Pb) from 290 archaeological sites dating between 7000 BC to modern times. The open-access dataset also includes detailed chronological, contextual, and laboratory/sample preparation information for each measurement. The collated data are deposited on the open-access CAMBIO data community via the Pandora Initiative data platform ( https://pandoradata.earth/organization/cambio ).


Assuntos
Arqueologia , Isótopos , Chumbo , Animais , Humanos , Região do Caribe , América Central
12.
Vet Clin North Am Exot Anim Pract ; 27(3): 585-592, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38627108

RESUMO

This article provides an overview of the development of exotic animal medicine in Latin America (LATAM), highlighting its historical evolution, current evidence, and future considerations. The practice of exotic animal medicine began in the 1970s and 1980s. The lack of knowledge and scientific resources led to the extrapolation of veterinary care for exotic species from human and companion animal medicine. However, from the 21st century onwards, globalization and collaboration among veterinary professionals have allowed greater access to knowledge and techniques for the treatment of exotic species in LATAM.


Assuntos
Animais Exóticos , Medicina Veterinária , Animais , Medicina Veterinária/tendências , México , América do Sul , América Central , História do Século XX
13.
Toxins (Basel) ; 16(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38535808

RESUMO

Central America is home to one of the most abundant herpetofauna in the Americas, occupying only 7% of the continent's total area. Vipers and lizards are among the most relevant venomous animals in medical practice due to the consequences of envenomation from the bite of these animals. A great diversity of biomolecules with immense therapeutic and biotechnological value is contained in their venom. This paper describes the prominent leading representatives of the family Viperidae, emphasizing their morphology, distribution, habitat, feeding, and venom composition, as well as the biotechnological application of some isolated components from the venom of the animals from these families, focusing on molecules with potential anti-thrombotic action. We present the leading protein families that interfere with blood clotting, platelet activity, or the endothelium pro-thrombotic profile. In conclusion, Central America is an endemic region of venomous animals that can provide many molecules for biotechnological applications.


Assuntos
Trombose , Animais , América Central , Coagulação Sanguínea , Biotecnologia , Plaquetas
14.
Sci Rep ; 14(1): 2972, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453955

RESUMO

Humans have a long history of transporting and trading plants, contributing to the evolution of domesticated plants. Theobroma cacao originated in the Neotropics from South America. However, little is known about its domestication and use in these regions. In this study, ceramic residues from a large sample of pre-Columbian cultures from South and Central America were analyzed using archaeogenomic and biochemical approaches. Here we show, for the first time, the widespread use of cacao in South America out of its native Amazonian area of origin, extending back 5000 years, likely supported by cultural interactions between the Amazon and the Pacific coast. We observed that strong genetic mixing between geographically distant cacao populations occurred as early as the middle Holocene, in South America, driven by humans, favoring the adaptation of T. cacao to new environments. This complex history of cacao domestication is the basis of today's cacao tree populations and its knowledge can help us better manage their genetic resources.


Assuntos
Cacau , Domesticação , Humanos , Cacau/genética , América do Sul , América Central
15.
Int J Infect Dis ; 143: 107018, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38522611

RESUMO

BACKGROUND: Human T-lymphotropic viruses (HTLV)-1 infection is endemic in many countries of Central and South America and Caribbean (CSA&C). Neither screening nor surveillance programs exist for HTLV-1/2 infection among pregnant women in this region. Neither in Western nations with large migrant flows from HTLV-1/2 endemic regions. METHODS: Systematic review and meta-analysis of the prevalence of HTLV-1/2 infection among CSA&C pregnant women. We included studies searching EMBASE, PubMed/MEDLINE, Scopus, and Web of Science from inception to February 15, 2023. This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. RESULTS: We identified a total of 620 studies. Only 41 were finally included in the meta-analysis. Most studies (61.0%) were from Brazil and Peru (14.6%). The total number of participants was 343,707. The pooled prevalence of HTLV-1/2 infection among CSA&C pregnant women was 1.30% (95% CI: 0.96-1.69) using anti-HTLV-1/2 antibody screening tests. There was a high heterogeneity (I2 = 98.6%). Confirmatory tests gave an HTLV-1 infection rate of 1.02% (95% CI: 0.75-1.33). CONCLUSIONS: The prevalence of HTLV-1/2 infection among CSA&C pregnant women is 1.3%, most cases being HTLV-1. This rate is greater than for other microbial agents regularly checked as part of antenatal screening (such as HIV, hepatitis B, or syphilis). Thus, HTLV-1/2 antenatal testing should be mandatory among CSA&C pregnant women everywhere.


Assuntos
Infecções por HTLV-I , Infecções por HTLV-II , Vírus Linfotrópico T Tipo 1 Humano , Vírus Linfotrópico T Tipo 2 Humano , Complicações Infecciosas na Gravidez , Humanos , Gravidez , Feminino , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-II/epidemiologia , Prevalência , Região do Caribe/epidemiologia , América do Sul/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , Vírus Linfotrópico T Tipo 2 Humano/imunologia , América Central/epidemiologia
16.
South Med J ; 117(3): 141-144, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428935

RESUMO

OBJECTIVE: The objective of this study was to describe anthropometric measures from internationally adopted children. Internationally adopted children are at risk for poor growth and development and there is no standardized growth chart evaluation for internationally adopted children due to variations in growth, genetics, and environmental exposures. METHODS: This is a retrospective chart review of 882 patients seen in an international adoption clinic between 2010 and 2017. Anthropometric measurements were converted to Z scores for weight, height, head circumference, and body mass index. RESULTS: A total of 41 countries and 16 subregions were represented. Central America, northern Africa, southern Africa, and southern Europe were the only subregions that had positive mean Z scores for weight, and southeast Asia had the lowest mean Z score for weight (n = 40, -1.76). No subregion had a positive mean Z score for height, and western Asia had the lowest overall mean Z score for height (n = 2, -2.44). Mean Z score for body mass index was positive in several subregions. CONCLUSIONS: Growth is an important predictor of health and development, and this study adds to the literature on growth patterns of internationally adopted children.


Assuntos
Criança Adotada , Criança , Humanos , Estudos Retrospectivos , Índice de Massa Corporal , Europa (Continente) , América Central
17.
J Zoo Wildl Med ; 55(1): 224-234, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38453507

RESUMO

Ten cases of small intestinal tympany with or without volvulus were documented in Central American river turtles (Dermatemys mawii). These turtles were under managed care at the Philadelphia Zoo in Philadelphia, PA, USA, with one case followed after transfer to a different institution. The primary clinical presentation was abnormal buoyancy in nearly all cases (9/10) and anorexia in two cases (2/10). Five of 10 turtles with suspected or radiographically confirmed small intestinal tympany recovered (5/10), whereas five cases (5/ 10) resulted in death or euthanasia. In all fatal cases (5/5), small intestinal volvulus was identified at gross necropsy, with concurrent colonic volvulus identified in 2/5 cases. Other notable necropsy findings were hepatic lipidosis (3/5) and thrombosis of intestinal or renal vasculature (2/5). In all fatal cases (5/5), there was short (1 to 2 days) clinical progression from abnormal buoyancy to death or euthanasia. In the majority of cases (6/10), an abrupt change in diet, notably the overfeeding of fresh fruit or excessive amounts of mulberry (Morus spp.) browse, or ingestion of indigestible foreign material, occurred prior to presentation. Temporary suboptimal environmental temperatures were suspected prior to the onset of clinical signs in 4/10 cases. Optimal husbandry conditions including nutrition and environmental temperature appear vital to preventing this condition. Recognition of early clinical signs of this condition, such as abnormal buoyancy and anorexia, and environmental correction or medical therapy, may prevent fatality and result in a better outcome in these cases.


Assuntos
Volvo Intestinal , Tartarugas , Animais , Volvo Intestinal/diagnóstico , Volvo Intestinal/veterinária , Anorexia/veterinária , Dieta , América Central
18.
Conserv Biol ; 38(4): e14251, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38462849

RESUMO

Central America and the Caribbean are regularly battered by megadroughts, heavy rainfall, heat waves, and tropical cyclones. Although 21st-century climate change is expected to increase the frequency, intensity, and duration of these extreme weather events (EWEs), their incidence in regional protected areas (PAs) remains poorly explored. We examined historical and projected EWEs across the region based on 32 metrics that describe distinct dimensions (i.e., intensity, duration, and frequency) of heat waves, cyclones, droughts, and rainfall and compared trends in PAs with trends in unprotected lands. From the early 21st century onward, exposure to EWEs increased across the region, and PAs were predicted to be more exposed to climate extremes than unprotected areas (as shown by autoregressive model coefficients at p < 0.05 significance level). This was particularly true for heat waves, which were projected to have a significantly higher average (tested by Wilcoxon tests at p < 0.01) intensity and duration, and tropical cyclones, which affected PAs more severely in carbon-intensive scenarios. PAs were also predicted to be significantly less exposed to droughts and heavy rainfall than unprotected areas (tested by Wilcoxon tests at p < 0.01). However, droughts that could threaten connectivity between PAs are increasingly common in this region. We estimated that approximately 65% of the study area will experience at least one drought episode that is more intense and longer lasting than previous droughts. Collectively, our results highlight that new conservation strategies adapted to threats associated with EWEs need to be tailored and implemented promptly. Unless urgent action is taken, significant damage may be inflicted on the unique biodiversity of the region.


Ciclones, olas de calor, sequías y lluvias intensas son eventos comunes en Centroamérica y el Caribe, cuya frecuencia, intensidad y duración se espera aumente durante el siglo XXI a causa del cambio climático. Sin embargo, en la actualidad, se desconoce cuál será la incidencia de estos eventos meteorológicos extremos (EME) dentro de las áreas protegidas. En este estudio examinamos la exposición histórica y futura a los extremos climáticos y comparamos el grado de exposición dentro y fuera de las áreas protegidas de toda la región por medio de 32 métricas que describen distintas dimensiones (intensidad, duración y frecuencia) de las olas de calor, los ciclones, las sequías y las precipitaciones. Los resultados indican que a medida que aumente el número de EME, las áreas protegidas estarán más expuestas a los extremos climáticos que las áreas no protegidas. Esto es especialmente cierto en el caso de las olas de calor, que, según las proyecciones, tendrán una intensidad y una duración medias significativamente mayores, y de los ciclones tropicales, que afectarán más gravemente a las zonas protegidas en los escenarios intensivos en carbono. Nuestros resultados también indican que las zonas protegidas estarán significativamente menos expuestas a sequías o lluvias torrenciales que las zonas no protegidas. Sin embargo, las sequías que podrían amenazar la conectividad entre áreas protegidas son cada vez más frecuentes en esta región. Se estima que aproximadamente el 65% del área de estudio experimentará al menos un episodio de sequía más intenso y duradero que las sequías anteriores. En conjunto, nuestros resultados ponen de relieve la necesidad de diseñar y aplicar con prontitud nuevas estrategias de conservación adaptadas a las amenazas asociadas a los EWE. A menos que se tomen medidas urgentes, la biodiversidad única de la región podría sufrir daños considerables.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Clima Extremo , Animais , América Central , Ovinos/fisiologia , Tempestades Ciclônicas , Secas , Feminino
19.
PLoS One ; 19(2): e0297840, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38422027

RESUMO

Global biodiversity is negatively affected by anthropogenic climate change. As species distributions shift due to increasing temperatures and precipitation fluctuations, many species face the risk of extinction. In this study, we explore the expected trend for plant species distributions in Central America and southern Mexico under two alternative Representative Concentration Pathways (RCPs) portraying moderate (RCP4.5) and severe (RCP8.5) increases in greenhouse gas emissions, combined with two species dispersal assumptions (limited and unlimited), for the 2061-2080 climate forecast. Using an ensemble approach employing three techniques to generate species distribution models, we classified 1924 plant species from the region's (sub)tropical forests according to IUCN Red List categories. To infer the spatial and taxonomic distribution of species' vulnerability under each scenario, we calculated the proportion of species in a threat category (Vulnerable, Endangered, Critically Endangered) at a pixel resolution of 30 arc seconds and by family. Our results show a high proportion (58-67%) of threatened species among the four experimental scenarios, with the highest proportion under RCP8.5 and limited dispersal. Threatened species were concentrated in montane areas and avoided lowland areas where conditions are likely to be increasingly inhospitable. Annual precipitation and diurnal temperature range were the main drivers of species' relative vulnerability. Our approach identifies strategic montane areas and taxa of conservation concern that merit urgent inclusion in management plans to improve climatic resilience in the Mesoamerican biodiversity hotspot. Such information is necessary to develop policies that prioritize vulnerable elements and mitigate threats to biodiversity under climate change.


Assuntos
Biodiversidade , Mudança Climática , Animais , México , América Central , Espécies em Perigo de Extinção , Florestas
20.
Parasite ; 31: 1, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38353582

RESUMO

Blood parasites of the genus Hemolivia Petit, Landau, Baccam and Lainson, 1990 (Adeleorina: Karyolysidae) are hemogregarines of ectothermic vertebrates, such as lizards, chelonians, and toads. Only five species of Hemolivia from vertebrate hosts and one from their tick vector have been described so far. In the present study, Central American wood turtles (Rhinoclemmys pulcherrima manni) originating from Southern Nicaragua were screened for the presence of hemogregarines. Ten out of 30 specimens (33.3%) were positive for Hemolivia using both approaches - microscopy and PCR-based analyses. Phylogenetic analyses based on the 18S rRNA gene revealed the presence of two haplotypes, both placed as sister taxa in the Hemolivia clade. Their phylogenetic position was supported by high bootstrap values and high posterior probabilities, suggesting that there are at least two new distinct haplotypes corresponding to two distinct species. However, the specimens of each haplotype were microscopically indistinguishable from each other based on the gamont morphology, therefore, only a single species could be described and named, as Hemolivia pulcherrima n. sp. We consider that the uniform morphology of the most common blood stages of species of the genus Hemolivia complicates their differential diagnosis. Sequence divergence and different host spectra, therefore, remain the only differentiating tools.


Title: Espèces d'Hemolivia infectant les tortues peintes d'Amérique centrale (Rhinoclemmys pulcherrima manni) et problèmes de diagnostic différentiel au sein du genre Hemolivia. Abstract: Les parasites sanguins du genre Hemolivia Petit, Landau, Baccam et Lainson, 1990 (Adeleorina : Karyolysidae) sont des hémogrégarines de vertébrés ectothermes, tels que les lézards, les tortues et les crapauds. Seules cinq espèces d'Hemolivia provenant d'hôtes vertébrés et une de leur tique vectrice ont été décrites jusqu'à présent. Dans cette étude, des tortues peintes d'Amérique centrale (Rhinoclemmys pulcherrima manni) originaires du sud du Nicaragua ont été examinées pour détecter la présence d'hémogrégarines. Dix tortues sur 30 (33,3 %) étaient positives pour Hemolivia en utilisant les deux approches de microscopie et d'analyse de PCR. Les analyses phylogénétiques basées sur le gène de l'ARNr 18S ont révélé la présence de deux haplotypes, tous deux placés comme taxons frères dans le clade Hemolivia. Leur position phylogénétique était étayée par des valeurs de bootstrap et des probabilités postérieures élevées, suggérant qu'il existe au moins deux nouveaux haplotypes distincts correspondant à deux espèces distinctes. Cependant, les spécimens de chaque haplotype étaient impossibles à distinguer les uns des autres au microscope sur la base de la morphologie des gamontes. Par conséquent, une seule espèce a pu être décrite et nommée, comme Hemolivia pulcherrima n. sp. Nous considérons que l'uniformité de la morphologie des stades sanguins les plus courants des espèces du genre Hemolivia complique leur diagnostic différentiel. Les divergences de séquences et les différents spectres d'hôtes restent donc les seuls outils de différenciation.


Assuntos
Lagartos , Tartarugas , Animais , Filogenia , Diagnóstico Diferencial , Lagartos/parasitologia , América Central
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