Search Results (700)

Mantidae exhibits the most extensive adaptive radiation within the order Mantodea; however, studies elucidating their internal phylogenetic relationships and spatio-temporal diversification patterns remain scarce. This study aims to resolve the long-standing taxonomic uncertainties within Mantidae by testing the hypothesis that the polyphyletic nature of several subfamilies—specifically Tenoderinae and Hierodulinae—is linked to an incomplete understanding of their mitochondrial genomic evolution. To address this, we assembled 16 complete Mantodea mitochondrial genomes, including seven representatives of the tribe Archimantini (Mantidae: Hierodulinae). Of these, 10 mitogenomes conform to the ancestral insect mitochondrial gene order proposed by Cameron and colleagues, but six mitochondrial gene orders do not conform to the ancestral insect mitochondrial gene order. We identified typical mantodean mitochondrial rearrangement patterns in three species, characterized by gene duplications within the trnA-trnR-trnN-trnS-trnE-trnF and CR-trnI-trnQ-trnM-trnM-ND2 gene cluster. Phylogenetic analyses corroborate the monophyly of Orthoderinae, Mantinae, Choeradodinae, Vatinae, and Archimantini within Mantidae; conversely, Tenoderinae and Hierodulinae are resolved as polyphyletic assemblages. Divergence time estimation indicates that the split between extant Mantodea and Blattodea occurred during the Middle Permian (275.4 Ma, 95% HPD: 207.07–329.09 Ma). Mantidae originated during the Late Cretaceous (87.83 Ma, 95% HPD: 58.89–118.23 Ma), with the diversification of most subfamilies of Mantidae occurring during the Late Cretaceous (80.48 Ma; 95% HPD: 54.86–106.41 Ma). Historical biogeographic analysis and the estimated divergence times suggests that the common ancestor of Mantidae originated within Gondwana during the Late Cretaceous. Ancestral range reconstructions identify Australasia realms and Neotropical realms as the most probable center of origination for Mantidae and achieved a global distribution by expanding along the trans-Antarctic route and leveraging the ‘Indian Ark’ effect. Full article

This study investigated the RNA virome associated with the phlebotomine sand fly Pintomyia fischeri using a metatranscriptomic approach applied to the Meta29 library, composed of 21 specimens collected at the São Paulo Zoo, Brazil. Read-based taxonomic analysis revealed a diverse viral community composed of viruses associated with the families Iflaviridae, Narnaviridae, Partitiviridae, Reoviridae, Solemoviridae, Tombusviridae, Totiviridae, and Tymoviridae, in addition to highly abundant unclassified RNA viruses related to the ShiM 2016 group. Assembly and annotation analyses enabled the characterization of four viral RNA genomes associated with the families Partitiviridae (PfPartitiV-1a-SP, PfPartitiV-1b-SP, and PfPartitiV-2-SP) and Narnaviridae (PfNarnaV-1-SP). Sequence comparisons revealed low amino acid identity relative to currently available reference viral sequences, supporting the classification of these sequences as highly divergent and potentially novel viral lineages. Structural modeling of the RNA-dependent RNA polymerase (RdRp) proteins identified the viral polymerase-specific catalytic motifs A, B, and C. Phylogenetic analyses further supported the evolutionary divergence of the identified viruses relative to currently described taxa. Overall, these findings expand current knowledge of viral RNA diversity associated with Neotropical sand flies and highlight the value of metatranscriptomic approaches for the detection and characterization of previously undescribed viruses associated with medically important insect vectors. Full article

Advances in biotechnological tools have accelerated the genomic characterization of non-model organisms, providing insights for broader bioprospecting efforts. In this context, Hyphessobrycon, one of the most species-rich and widely distributed genera in the family Characidae, remains largely unexplored at the mitogenomic level. We sequenced the complete mitogenomes of three Hyphessobrycon species, compared them with those of other Hyphessobrycon species, and conducted a phylogenetic analysis. We found that Hyphessobrycon mitogenomes are similar in terms of structure and size, codons with relative synonymous codon usage >1 usually end with A or T, and the genus Hyphessobrycon is polyphyletic. Our study provides additional evidence for the phylogenetic relationships in Characidae; however, mitogenomes of more Hyphessobrycon species need to be characterized in future studies. Full article

Ultrasound is a fundamental diagnostic imaging tool in veterinary medicine that allows for the noninvasive, real-time evaluation of abdominal organs. However, reference ultrasound data for neotropical marsupials is scarce, which hinders diagnostic interpretation of ultrasound images of these species. The present study aimed to describe the morphological and biometric ultrasound characteristics of the abdominal organs of white-eared opossums (Didelphis albiventris) treated at a wildlife rehabilitation center in southern Brazil. Sixteen clinically stable opossums, with an average body mass of 1.4 kg, underwent abdominal ultrasonography using a multifrequency linear transducer (7–12 MHz). We analyzed parameters such as shape, contour, echogenicity, echotexture, and anatomical relationships between adjacent structures, in addition to taking biometric measurements of different abdominal organs. Most structures presented characteristics similar to those described in small domestic dogs and cats. However, species-specific particularities were observed, including decreased renal corticomedullary distinction, slightly coarser renal and prostatic echotexture, and a smaller abdominal aorta diameter. It is concluded that abdominal ultrasonography is an effective method for the anatomical evaluation of white-eared opossums. Full article

Mustelids are a very diverse carnivoran group, boasting the largest number of carnivoran species today, with the most extreme ecological adaptations. Nevertheless, Neotropical Lyncodontini, one Neotropical mustelid subfamily, is one of the least studied from a genetic and evolutionary perspective. The use of small fragments of three mitochondrial (mt) markers (NADH5, 12S rRNA, and D-loop) proved to be very useful for recovering relevant information on the evolutionary history of Neotropical Lyncodontini species of the genera Galictis and Lyncodon. This study used the largest population sample analyzed to date for G. vittata (13 specimens from Guatemala, Colombia, Ecuador, Peru, Bolivia, and French Guiana) and reports for the first time sequences for three mt markers for L. patagonicus other than the mtCyt-b gene. The main results obtained were the following. (1) The haplotype and nucleotide diversity of G. vittata was lower than these statistics measured in other studies of G. cuja in southern and southeastern Brazil. (2) There was evidence from two analyses of a possible population expansion of the female lineages of G. vittata, which began between 635,000 and 370,000 years ago (ya) (mismatch distribution), whereas another procedure (BSP) detected population growth from 500,000 to 80,000 ya, with a population decrease around 40,000 ya. (3) Three genetically distinct groups were detected within G. vittata. One group was in Central America and northern Colombia, another in French Guiana, and the third in the rest of South America. (4) The origin of Neotropical Lyncodontini was older than in other studies (late Miocene, early Pliocene). (6) Some of the analyses detected a closer relationship between L. patagonicus and G. cuja than the latter with G. vittata. This could show that Galictis might be a paraphyletic genus. (7) Many analyses detected that the L. patagonicus haplotypes were the first to originate in situ in South America before the definitive closure of the isthmus of Panama, followed by those of G. cuja, with G. vittata showing the most recent haplotypes. This could indicate that the origin of the current Neotropical Lyncodontini occurred in the south of South America and that colonization occurred towards the north. Full article

Male and female paper wasps (Vespidae: Polistinae) perform different behavioral roles. Thus, sexes may experience distinct selective pressures that may ultimately affect body size, shape, and proportions. We investigated this in the neotropical Polistes simillimus. We compared 100 males and 100 females using linear morphometrics, geometric morphometrics, and allometric analyses of head, mesosoma, forewing, and fore femur. Females were larger than males in all linear measurements. After correcting for body size, males exhibited wider heads, longer mesosomas, and longer fore femora, whereas females had longer heads. Positive allometry of mesosoma length was detected in males and negative allometry of fore femur length in females. Geometric morphometrics confirmed differences in both forewing (rounder in males, elongated in females) and mesosoma (stouter in males). These findings are consistent with the contrasting behavioral demands experienced by each sex; they also generate testable hypotheses regarding the evolution of flight performance in these insects. Full article

The effects of urbanization on woodland insectivorous mixed-species flocks have been little studied, and no seasonal studies have been conducted. This study aimed to describe the structure and seasonal dynamics of insectivorous mixed flocks in urban green areas of Buenos Aires City, Argentina. A total of 82 visits were conducted from April 2025 to March 2026. The potential effects of temperature, precipitation, humidity, and Julian day on flock occurrence were analyzed. The most frequent and abundant bird species in flocks were the White-crested Tyrannulet (Serpophaga subcristata), the Greyish Baywing (Agelaioides badius), the Masked Gnatcatcher (Polioptila dumicola), and the Tropical Parula (Setophaga pitiayumi). Serpophaga subcristata, Polioptila dumicola, and Setophaga pitiayumi tended to occur together in flocks. Flocks were observed in both native and exotic tree species. Flock occurrence was significantly associated with Julian day and peaked in autumn and during the early winter, coinciding with the non-breeding season. These results align with other studies conducted in subtropical and temperate regions. The significant relationship between flock occurrence and Julian day during the non-breeding season suggests that mixed flocking behavior helps individuals and pairs of different bird species by likely improving access to food and reducing predation risk as they move outside their breeding territories. A better understanding of the effects of urbanization on mixed flocks would be gained by comparing the spatial and temporal dynamics of flocking behavior in insectivorous birds in urban green areas with those in the region’s native woodlands. Full article

Specklinia is an orchid genus composed of approximately 120 species. Although it has only been recognized recently as a monophyletic group, the presence of several poorly understood species complexes has led in the application of numerous names to taxa not occurring in Mexico and northern Central America. This study presents an updated and comprehensive systematic revision of Specklinia in Mexico, based on recent taxonomic and phylogenetic evidence. We examined Specklinia specimens housed in Mexican and international herbaria, as well as cultivated specimens and observations recorded on iNaturalist Mexico. For each species, we provided a description, taxonomic history, potential distribution model, conservation status assessment, photographic plate or botanical illustration are provided, along with information on distribution, habitat, phenology and comparisons with morphologically similar species. Twenty-two Specklinia species are accepted for Mexico, including five described as new (S. orbiculata, S. perez-garciae, S. solanoi, S. wendtii, and S. xoconochcana.) and two newly recorded for the country (S. acicularis and S. juddii). The identity of Mexican taxa morphologically similar to S. digitale, S. endotrachys, and S. grobyi are re-evaluated here. New combinations in Specklinia are proposed for Pleurothallis choconiana and P. hagsateri, which are recognized as distinct species. Lectotypes are designated for Epidendrum lanceola, E. tribuloides, Pleurothallis marginata, P. pergarcilis, P. microphylla, P. lateritia and P. spathulata. An identification key to the Mexican species of Specklinia is also provided. This study establishes a robust taxonomic framework for Specklinia in Mexico and highlights the need for continued systematic and conservation research, particularly in light of the proposed inclusion of 11 species under a risk category. Full article

Digestive enzymes such as pancreatic lipase (PL), α-glucosidase (AG), and α-amylase (AA) play key roles in the hydrolysis of dietary lipids and carbohydrates and are therefore relevant biochemical targets for evaluating compounds with potential to modulate postprandial metabolic responses. Neurolaena lobata (L.) R. Br. ex Cass. (Asteraceae) is a neotropical medicinal species traditionally used for several health-related conditions, including metabolic complaints. This study evaluated the in vitro inhibitory activity of the hydroalcoholic extract, selected VLC fractions, and isolated metabolites from N. lobata leaves against PL, AG, and AA. Enzyme inhibition screening of the extract and VLC fractions was used to select fractions for phytochemical investigation, affording six known metabolites: the sesquiterpene lactones neurolenin B (C1) and lobatin A (C2), the benzoic acid derivatives p-hydroxybenzoic acid (C3) and 3,4-dihydroxybenzoic acid (C4), and the flavonoids 6-hydroxykaempferol 3,7-dimethyl ether (C5) and quercetagetin 3,7-dimethyl ether (C6). The hydroalcoholic extract and the MeOAc and iPrOH fractions inhibited PL, AG, and AA. Among the isolated compounds, C1, C2, C5 and C6 inhibited PL and AG, with IC₅₀ values ranging from 134 to 615 µM and from 170 to 639 µM, respectively, whereas all compounds showed weak AA inhibition. Exploratory kinetic analysis yielded apparent inhibition profiles mainly consistent with competitive behavior; C6 showed an apparent profile consistent with noncompetitive inhibition against AG under the assay conditions used. These findings expand the phytochemical and in vitro bioactivity profile of N. lobata and provide preliminary evidence of digestive enzyme modulation in isolated enzyme systems, without establishing therapeutic efficacy. Full article

In the Neotropical Savanna domain, few equations are available for estimating biomass stocks in Cerrado sensu stricto (CSS), despite the importance of such tools for estimating carbon stocks, understanding ecosystem functioning, and supporting conservation actions. We conducted forest inventories in 40 temporary 1000 m² plots in southeastern Brazil to estimate total and compartmental biomass stocks and to model biomass using structural and edaphic predictors. Total biomass (TB) included aboveground woody biomass (AGWB), necromass, litter, and belowground biomass (BGB). AGWB was estimated for trees with basal diameter ≥ 5 cm using a previously fitted regional equation. Root biomass was sampled using a 1 m³ trench excavated at a single point adjacent to each plot. Necromass was quantified using the line-intersect method along a 50 m transect, considering debris with diameter ≥ 3 cm. Litter was sampled using a 0.25 m² frame placed at the center of each plot. Biomass was modeled on an area basis using a hierarchical approach for TB, total tree biomass (TTB = AGWB + BGB), and AGWB. Mean stocks (Mg ha⁻¹ ± s.d.) were 45.24 ± 17.32 (TB), 20.47 ± 11.26 (AGWB), 18.47 ± 10.88 (BGB), 5.49 ± 4.18 (litter), and 0.81 ± 1.62 (necromass). Models selected using the Akaike Information Criterion (AIC) and validated by repeated k-fold cross-validation achieved rŷy = 0.76, 0.72, and 0.94 and RMSE = 24.40%, 27.06%, and 18.10% for TB, TTB, and AGWB. As the equations were calibrated for CSS under the environmental conditions of the Brazilian semiarid region, their transferability to other Cerrado regions should be considered with caution. The inclusion of soil variables (e.g., Al, Mg, and sand) improved predictions, reducing relative costs and taxonomic dependence, while incorporating nutritional adaptations to the acidic soils characteristic of the biome. Full article

Sub-Andean forests of the Colombian Central Cordillera are among the most biodiverse and threatened Neotropical ecosystems, yet their floristic composition, vegetation structure, and aboveground carbon storage remain poorly documented. We characterized the floristic diversity, vegetation structure, and aboveground carbon storage of the El Mangón sub-Andean forest remnant (24 ha; 1600–1700 m a.s.l., Cauca, Colombia) using general (non-systematic) collections across the total area and a structural inventory in five 50 × 4 m transects (498 individuals, 35 species). A total of 281 species, 209 genera, and 99 families were recorded; epiphytes represented 44.13% of species, exceeding typical values (25–35%) for this forest type. Diversity indices were intermediate (H′ = 2.55; DMg = 5.47; 1-D = 0.89). Palicourea crocea dominated structurally (IVI = 45.12), whereas aboveground carbon—re-estimated with the pantropical model (total = 72.85 Mg C ha⁻¹)—was concentrated in a few large canopy trees (Alchornea latifolia, 32%; Myrsine guianensis, 16%), with P. crocea contributing only 3.6%. Three novel carbon indices (CVI, CCEI, CSI) integrate storage magnitude with capture efficiency and spatial stability; the CSI differed significantly among spatial-distribution groups (Kruskal–Wallis, p = 0.003), being higher in aggregated, large-stemmed species than in low-aggregation species. El Mangón ranks among the most diverse sub-Andean remnants documented to date in southwestern Colombia, underscoring its conservation priority in an increasingly fragmented landscape. Full article

Biodiversity loss in aquatic ecosystems is accelerating, yet whether the effects of different biodiversity facets on biogeochemical processes are consistent or environmentally contingent remains poorly understood. Benthic invertebrate bioturbators drive nutrient exchange at the sediment–water interface of shallow aquatic ecosystems, but how sediment trophic status modulates the effects of their richness, identity, and composition on benthic–pelagic nutrient cycling is unclear. We conducted a factorial microcosm experiment using three functionally and phylogenetically distinct species—Campsurus melanocephalus (Ephemeroptera), Heteromastus similis (Polychaeta), and Heleobia australis (Gastropoda)—assembled as monocultures, bicultures, and tricultures across a gradient of sediment organic matter concentration ([OM]) representative of natural variability in a neotropical coastal lagoon. Species richness produced a consistent, saturating enhancement of NH₃ fluxes that was independent of sediment trophic status, while species identity strongly differentiated monoculture effects in a pattern that was likewise stable across the [OM] gradient. In contrast, although biculture compositions did not differ from one another across the [OM] gradient, the overall magnitude of biculture-mediated NH₃ fluxes increased with sediment trophic status, suggesting that multispecies assemblage effects are more responsive to environmental context than those of single species. These findings reveal that biodiversity facets diverge not only in how strongly they affect ecosystem functioning, but also in how sensitive their effects are to environmental variation. We therefore conclude that predicting benthic–pelagic nutrient exchange in shallow coastal ecosystems requires considering both the biological structure of bioturbator assemblages and the organic matter context of the sediment. Full article

Background: Brazilian wasp venoms represent a clinically relevant yet underexplored source of bioactive molecules with important implications for allergy, toxicology, and neuropharmacology. This review discusses the biological and immunological activities of venoms from Neotropical wasp species prevalent in Brazil, particularly within the genera Polybia, Synoeca, Polistes, and Agelaia, with emphasis on venom composition, IgE-mediated hypersensitivity, and ion-channel modulation. Methods: A narrative literature review was conducted using studies focused on venom characterization, electrophysiological effects, immune responses, and clinical manifestations associated with Brazilian and other Hymenoptera species. Results: Brazilian wasp venoms contain a diverse repertoire of peptides, enzymes, and low-molecular-weight compounds that act synergistically on multiple cellular targets. Among these, mastoparan-like peptides exhibit antimicrobial, immunomodulatory, and membrane-disruptive activities, contributing to inflammation and cellular dysfunction. In addition, several venom components interact with ion channels and neuronal receptors, modulating neuronal excitability and synaptic signaling, which highlights their potential applications in neuropharmacology. Simultaneously, allergenic proteins can induce IgE sensitization and immediate hypersensitivity reactions ranging from localized manifestations to systemic anaphylaxis. The marked taxonomic and biochemical diversity of Brazilian wasps contributes to substantial variability in venom composition and clinical outcomes. Conclusions: Overall, these venoms constitute a valuable and still insufficiently explored source of biologically active compounds with potential applications in allergy diagnosis, venom immunotherapy, and drug development. Full article

Handroanthus chrysanthus (Jacq.) S.O. Grose is a Neotropical tree species highly valued for its ornamental beauty, durable timber, and medicinal properties. However, overexploitation and the recalcitrant nature of its seeds have constrained propagation and conservation efforts, and the species has been listed as Vulnerable on the IUCN Red List since 2020. In this study, a direct adventitious shoot regeneration system was developed for H. chrysanthus by systematically evaluating explant type, basal medium, plant growth regulator combination, and light quality. Hypocotyls were identified as the most responsive explants for shoot induction, and the highest adventitious shoot induction frequency, 51.79%, was obtained on Murashige and Skoog medium (MS) supplemented with 5 mg·L⁻¹ 6-benzylaminopurine, 0.5 mg·L⁻¹ indole-3-butyric acid, and 0.2 mg·L⁻¹ thidiazuron under white fluorescent light. The highest shoot multiplication coefficient, 3.27, was obtained on MS medium containing 4 mg·L⁻¹ 6-benzylaminopurine and 0.3 mg·L⁻¹ gibberellic acid. The maximum rooting frequency, 80%, was obtained on R14 medium after 30 days of culture. After acclimatization, 95% of the regenerated plantlets survived and grew vigorously under greenhouse conditions. To our knowledge, no direct adventitious shoot regeneration system has been reported for the Tabebuia alliance. This efficient regeneration protocol provides a practical platform for clonal propagation, germplasm conservation, and genetic improvement of H. chrysanthus and may also support regeneration and conservation in related endangered taxa within the Tabebuia alliance. Full article

Maxillariinae is one of the most diverse Neotropical orchid groups, yet little is known about its reproduction and pollination. We studied Maxillaria carinulata and Maxillaria meridensis on the eastern slope of the Cordillera Oriental in Caquetá, Colombia (2000–2300 m), using pollinator exclusion, controlled pollination, observations, and histochemical tests. Hand pollination was used for manual autogamy, geitonogamy, and xenogamy treatments. Bagged flowers produced no fruit, confirming dependence on pollinators. Apomixis and spontaneous selfing failed, but manual autogamy, geitonogamy, and xenogamy yielded high fruit sets, showing self-compatibility and cross-fertility. In M. carinulata, fruit set reached 93.3%, 86.7%, and 90%; in M. meridensis, 80.0%, 83.3%, and 86.7%. The independent natural fruit-set survey showed low fruit production under field conditions, with 4.7% of monitored flowers forming fruits in M. carinulata and 16.3% in M. meridensis, reflecting inefficient pollen transfer. Both species showed floral scent and osmophore-like activity; M. meridensis also produced lipids, proteins, sugars, and starch in specific tissues. Visitors, mainly Stethobaris weevils, were recorded on M. meridensis, but no pollinarium removal or deposition occurred. These findings highlight strong pollination limitations and support conserving habitats to sustain effective pollinators in Andean populations. Full article