Search Results (217)

Anaerobic digesters operating under neotropical conditions face significant technological constraints. High humidity, intense solar radiation, and pronounced diurnal temperature variations increase conductive, convective, and radiative heat losses. These factors reduce internal thermal stability and directly affect methane production rates and overall energy efficiency. As a result, thermal instability becomes a recurrent operational bottleneck in biogas plants without active temperature control. This review examines the thermal and dynamic behavior of anaerobic reactors from a process-engineering perspective. It integrates energy balances, heat-transfer mechanisms, and computational fluid dynamics (CFD) modeling. The combined effects of temperature gradients, hydrodynamic mixing patterns, and structural material properties are analyzed to determine their influence on thermal homogeneity, microbial stability, and methane yield consistency under mesophilic conditions. Technological strategies to mitigate thermal losses are evaluated. These include passive insulation using low-conductivity materials, geometry optimization supported by numerical modeling, and thermal recirculation schemes, as these factors govern temperature distribution and process resilience. Current limitations are also discussed, particularly the frequent decoupling between ADM1-based kinetic models and transient heat-transfer analysis. This separation restricts predictive capability under real-scale diurnal temperature oscillations. The development and validation of coupled hydrodynamic–thermal–biokinetic models under fluctuating neotropical boundary conditions are proposed as critical steps. Such integrated approaches can enhance operational stability, ensure consistent methane production, and improve energy self-sufficiency in organic waste valorization systems. Full article

The Veracruzan biogeographic province is a central part of the Gulf of Mexico slope and serves as an interface between the Neotropical Region, the Mexican Transition Zone, and the Nearctic Region. We provide an overview of amphibian and reptile diversity in the province, focusing on species richness, endemism, conservation status, and faunal similarity to neighboring biogeographic provinces. In the Veracruzan biogeographic province there are 343 native species of amphibians and reptiles, encompassing nearly one quarter of the Mexican herpetofauna, with over 85% of the families and over 90% of the genera found in Mexico represented. The province therefore possesses exceptional taxonomic richness. It has the fifth highest richness among Mexican biogeographic provinces. The herpetofauna comprises several Neotropical taxa and locally endemic species found among amphibians of montane and cloud forest fauna. Richness of amphibians and reptiles generally increases with province area. Regions of the Mexican Transition Zone exhibit a relatively higher species richness than their Neotropical neighbors. Analyses of faunal similarities between the Veracruzan province and its neighboring provinces and highlight the importance of geographic proximity, environmental continuity, and historical processes for assemblage composition. Amphibians are more threatened than reptiles, with high levels of endemism and vulnerability to habitat loss and emerging diseases, whereas reptiles are more threatened by habitat degradation, exploitation, and invasive species. Our findings show that the Veracruzan biogeographic province is an important reservoir of herpetofaunal diversity and a priority region for conservation in Mexico. Full article

Anostomidae is one of the most diverse families within the order Characiformes and is widely distributed across the river basins of the Neotropical region. Anostomids are known to host a rich diversity of metazoan parasites, including ectoparasites, such as monopisthocotylans, and endoparasites, such as nematodes, cestodes, and digeneans. The present study aims to develop an inventory of metazoan parasites recorded in fish of the Anostomidae family. A bibliographic review of metazoan parasite species in anostomids was conducted, using searches in different databases. This bibliographic review was complemented with information from books and book chapters on ictioparasitology. The data were compiled until January 2025. Based on the review, 191 taxa (126 are described at the species level and 65 were identified only to the genus level or higher taxonomic categories) of metazoan parasites associated with anostomid fishes were found. Monopisthocotyla and Nematoda were the taxonomic groups with the most parasitic associations at the species level, with 31 and 30 species, respectively. This study presents a comprehensive and updated inventory of metazoan parasites associated with fish from the family Anostomidae, covering over 170 years of research (1850–2025). This survey highlights the importance of anostomids as hosts for a rich parasitic fauna. Full article

Rhipicephalus microplus infestations are a major concern for cattle production in neotropical regions. Anti-tick vaccines represent a sustainable alternative to chemical acaricides; however, improving vaccine efficacy remains challenging. This study evaluated the protective efficacy of polypeptide-based formulations of pBm86 and pSubolesin administered as co-immunization or as a cocktail in naturally infested cattle. Twelve calves were assigned to three groups: G1: 100 μg pBm86 + 50 μg pSubolesin co-immunized; G2: same formulation in cocktail; and G3: control. The cocktail significantly reduced adult female tick numbers, oviposition, and larvae hatching (p < 0.05), achieving a vaccine efficacy of 75%. In contrast, co-immunization achieved 50% efficacy. Vaccinated cattle developed significantly increased antigen-specific IgG levels against Subolesin than Bm86. IgG antibodies recognized native tick proteins by Western blot, and their efficacy was confirmed in vitro using blood-feeding assays. These results indicate that the cocktail formulation showed improved efficacy compared with co-immunization in this study, possibly by affecting complementary biological processes in ticks. Finally, this study supports the development of multi-antigen, polypeptide-based vaccines as a promising and sustainable approach for the control of R. microplus under natural field conditions. Full article

The genus Xylaria comprises numerous species, particularly prevalent in tropical ecosystems such as those of Ecuador. Despite its ecological importance, the taxonomy of the genus remains challenging, and much of its diversity in the Neotropics remains under-documented. This study provides a preliminary characterization of the Xylaria diversity at the Estación Científica San Francisco, an Andean biodiversity hotspot in Southern Ecuador. Through an integrated approach including detailed macro- and micro-morphological descriptions and nuclear ribosomal DNA (nrDNA ITS and LSU) phylogenetic analyses, 20 Xylaria specimens were examined. As a result, ten species were recognized: Xylaria adscendens, X. cf. anisopleura, X. apiculata, X. curta, X. enterogena, X. fissilis, X. globosa, X. aff. telfairii, X. tuberoides, and X. aenea, the latter representing a new record for Ecuador. The phylogenetic analysis presented here serves as a preliminary systematic positioning of these specimens within the genus rather than a comprehensive global reconstruction. While these ribosomal markers provided preliminary insights into species relationships, partial incongruence with morphospecies highlights the evolutionary complexity of certain lineages and underscores the need for future multilocus studies. Furthermore, four additional phylotypes found in their anamorphic state are documented, suggesting that local diversity exceeds current records. By providing detailed morphological documentation supported by preliminary barcode data from a poorly sampled region, this study contributes vital information to the global understanding of Xylaria and underscores the importance of Southern Ecuador as a reservoir of fungal diversity. Full article

Anthurium (Araceae) is one of the most species-rich Neotropical genera, yet its infrageneric classification remains unresolved. This study tests the monophyly of the morphologically defined Anthurium sect. Pachyneurium diagnosed by rosulate habit, involute prefoliation, and absence of a collective vein with a focus on Brazilian species. Using target capture sequencing (Angiosperms353 probe set), we generated a phylogenomic dataset for 35 Anthurium species (18 from sect. Pachyneurium) and conducted maximum likelihood and coalescent-based analyses. Our results demonstrate that sect. Pachyneurium is not monophyletic as traditionally circumscribed. Brazilian species previously assigned to the section are recovered in three geographically structured and strongly supported lineages: Amazonian, Atlantic Forest, and Caatinga/Cerrado. The Atlantic Forest lineage is unexpectedly resolved as sister to A. coriaceum (sect. Urospadix), revealing an evolutionary relationship not predicted by morphology. Divergence-time estimates place the origin of crown Anthurium in the Paleocene (~62 Ma), with diversification of the Brazilian lineages occurring during the Miocene (20–3 Ma), coinciding with major geoclimatic events in South America. Our findings indicate that key diagnostic morphological characters are homoplastic and provide a phylogenomic framework for revising the infrageneric classification of Anthurium. By identifying evolutionarily distinct lineages, this study also contributes to prioritizing conservation efforts in threatened Neotropical biomes. Full article

The genus Auricularia holds significant ecological importance due to its role in wood decaying and notable economic value as both an edible and medicinal resource. This study investigates the diversity of Auricularia species in Colombian Andes using an integrative approach. Species identification was based on macromorphological and micromorphological characteristics, alongside molecular analyses employing ITS and LSU markers. A total of 184 sequences of 81 specimens and 30 species were used to construct a phylogenetic tree including RPB2 marker sequences taken from GenBank. The results revealed six Auricularia species in the Colombian Andes: A. subglabra, A. cornea, A. fuscosuccinea, A. nigricans, A. brasiliana, and the newly described A. ibaguensis. This study provides morphological descriptions, distribution records, and interspecific distinctions, aligning these taxa with four out of the five recognized Auricularia species complexes. Novel sequences deposited in GenBank enhance taxonomic resolution, particularly within the A. cornea complex. These findings contribute new insights into the taxonomy of Auricularia in the Colombian Andes and emphasize the need for further research on Neotropical species, which may show significant differences from taxa in other biogeographic regions. Full article

Cyanobacterial blooms are intensifying globally under climate warming, eutrophication, and hydrological alteration, yet most mechanistic understanding derives from temperate lakes. Tropical and neotropical freshwaters operate under persistently warm conditions, weak seasonality, and hydrological variability that can sustain extended bloom windows and alter toxin production patterns spatiotemporally, requiring targeted synthesis. This review synthesizes recent experimental and field evidence, complemented by foundational frameworks, to evaluate cyanobacterial diversity, functional ecology, and cyanotoxin dynamics in tropical freshwater habitats. We highlight recurring trait syndromes, coordinated sets of physiological and functional traits, that recur across warm systems, including buoyancy regulation, diazotrophy, and thermal tolerance, which confer competitive advantages under warm, nutrient-rich conditions. These traits are prominent in dominant genera such as Microcystis, Raphidiopsis, and Planktothrix. We assess how temperature, nutrient stoichiometry, water residence time, and light interact to modulate bloom persistence and toxin production. We summarize appropriate monitoring and management approaches suited to warm, hydrologically dynamic basins. These including strategies addressing internal loading and integrated early-warning frameworks combining molecular tools and remote sensing. Substantial gaps persist in toxin quantification, biogeochemical fluxes, molecular surveillance, and coordinated risk assessment across the tropics. We argue that region-specific, integrative frameworks are urgently needed to improve early-warning capacity and mitigate cyanoHAB risks in tropical freshwater ecosystems. Full article

At least seven species of wild cats inhabit Colombia, and these species are also distributed throughout Mexico, Central America, and the rest of South America (jaguar, puma, jaguarundi, ocelot, margay, tigrina, and Pampas cat). A checklist and review of phylogeographic and population genetic studies on these seven wild cat species has been conducted here, as this information is vital for effective conservation programs. The jaguar is the feline species on which the most population genetic studies have been carried out in the Neotropics. In general, little genetic structure has been found at a macro-geographic scale. Genetic diversity is high in countries such as Colombia, Peru, and Bolivia, and generally throughout the Amazon basin. However, genetic diversity is more moderate or even significantly lower in Mexico and the Brazilian Atlantic Forest. Much of the genetic research on the jaguar has focused on Brazil, Mexico, and Belize, but Colombia is also very well represented in these studies. However, there is a complete or very pronounced lack of data in other areas such as Venezuela, the Guianas, some Central American countries, Paraguay, and northern Argentina. After the jaguar, the most studied feline in Neotropics from a population genetics perspective is the puma. In North America, this species has low genetic diversity, while the diversity in Central America is moderate, and South America is where genetic diversity is highest. The countries best represented in these studies are Brazil (southern of the country), Mexico, Belize, and Argentina. However, countries like Colombia, Ecuador, Peru, and Paraguay are very poorly represented in puma genetic studies. Very few genetic studies have been conducted on the jaguarundi, despite its vast geographic distribution. In northern Mexico, its genetic diversity is very low, but in countries like Colombia, Peru, and Bolivia, genetic diversity is very high. Colombia is probably the country where jaguarundis have been genetically studied most extensively. The third wild cat species with the most molecular studies in Neotropics is the ocelot, although it lags considerably behind jaguars and pumas. Its genetic diversity is low in Texas and northern Mexico, but very high, especially in countries surrounding the Amazon basin. A good number of macro-geographic studies have been conducted on the ocelot, and these studies are very representative of ocelots in countries such as Colombia (probably the best represented country), Ecuador, Peru, Bolivia, Panama, and Costa Rica. However, there are other countries where molecular studies of the ocelot have not been carried out, such as Paraguay and Argentina, with the lack of such studies in Brazil being particularly noteworthy. Very few molecular studies have been conducted on the margay. In general, its genetic diversity is very high in all the studies performed. Colombia, Peru and Bolivia are very well represented, but the lack of molecular studies in Mexico, much of Central America, and South American countries such as Brazil, Paraguay, and Argentina is striking. The tigrina is one of the Neotropical wild cat species that requires the most molecular studies to unravel its complex systematics. Only the southern Brazilian tigrina (Leopardus guttulus), which was elevated to a new species, has generated comprehensive molecular information. Molecular studies of the Andean tigrina have revealed a very complex picture that, at present, does not allow us to know exactly how many species or taxa inhabit that area of South America and, therefore, to develop a conservation program that adequately correlates with that number of taxa. Finally, in the case of the Pampas cat, molecular studies are well represented with specimens from Peru, Bolivia, Chile, Argentina, Brazil and Uruguay. Studies are needed in Paraguay, and especially in Ecuador and southern Colombia (assuming a stable population of Pampas cats exists in the latter country), where even at the molecular level, the specific taxon (one species or five species) present has not yet been determined. All this information is essential for developing effective regional and global conservation programs for these magnificent creatures. In Colombia, the development of molecular studies with the puma, the tigrina, and the Pampas cat is of special interest. Full article

The recent recognition of the Neotropical otter (Lontra annectens) as a distinct species highlights the need to evaluate its genetic status and connectivity across fragmented tropical habitats. We analyzed genetic diversity, population structure, and recent demographic patterns of L. annectens from two contrasting regions in northern Costa Rica—Tortuguero National Park (TNP) and the Sarapiquí River Basin (SRB). Non-invasive fecal and anal-gland secretion samples collected during 2021–2022 were genotyped at ten nuclear DNA microsatellite loci. Genetic diversity was moderate across regions (mean allelic richness [AR] = 3.98–4.03, observed heterozygosity [Ho] = 0.52–0.58), expected heterozygosity [He] = 0.62–0.65) with no significant inter-regional differences. Bayesian clustering, principal component analysis, and pairwise F_ST (0.002) supported a near-panmictic population. Kinship analyses detected localized clusters of related individuals, suggesting weak but non-random structuring, while contemporary migration estimates indicated low-frequency, asymmetric gene flow from SRB to TNP. Bottleneck tests revealed signatures of recent demographic contraction in both regions, particularly in TNP. These findings demonstrate limited yet ongoing connectivity among riverine subpopulations and emphasize that increasing habitat fragmentation could erode this exchange. Maintaining hydrological corridors and monitoring genetically vulnerable subpopulations should be conservation priorities to preserve gene flow and long-term viability of L. annectens in northern Costa Rica. Full article

We used whole-genome sequencing to assemble the first complete mitogenome from a Mesentotoma Salmon, 1942 species. Mesentotoma was included in phylogenetic analyses along with 21 mitogenomes of other Entomobryinae. Maximum likelihood and Bayesian inferences yielded similar results; both analyses indicated that Mesentotoma is related to Willowsia jacobsoni and Entomobrya proxima. However, other genera of Entomobryinae, also lacking a mucronal spine (Desertia Tshelnokov, 1979 Calx Christiansen, 1958 and Isotobrya Womersley, 1934) need to be included in further analysis to verify their relationships, as well as other species of Mesentotoma. Furthermore, five species previously assigned to Entomobrya were transferred to Mesentotoma due to the absence of a mucronal spine. E. coeruleopicta Marlier, 1945 is a junior homonym of E. coeruleopicta Schött, 1917 and a replacement name is proposed: M. tranvercyana nom. nov., comb. nov. In addition, two new species of Mesentotoma from a Brazilian island are described and characterized by reduced macrochaetotaxy. This represents the first record of Mesentotoma in the Neotropical region, increasing its total number of valid species from eight to fifteen. We provided an identification key for the seven Mesentotoma species recorded in the Tropical zone. Full article

Antimicrobial resistance represents a critical challenge to global public health, driving the search for bioactive compounds in medicinal plants. The Fabaceae family stands out for its chemical richness and pharmacological properties; however, in the state of Tamaulipas, Mexico—an area of high diversity due to its location between the Nearctic and Neotropical regions—this flora remains largely unexplored. The objective of this review was to analyze the global scientific literature on the Fabaceae of Tamaulipas, integrating floristic records, phytochemistry, and antimicrobial activity. Of the 347 species recorded in the state, only 60 have phytochemical studies, and 43 have documented medicinal uses. The results show that extraction methods predominantly use polar solvents to isolate phenolic compounds, flavonoids, and alkaloids, which show efficacy against pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans. Despite limited local ethnobotanical documentation, the potential demonstrated by these species in other regions positions Tamaulipas as a strategic reservoir. This review identifies research gaps and emphasizes the need for systematic studies that validate traditional uses and prioritize bioprospecting of the flora of northeastern Mexico for the development of new therapeutic alternatives. Full article

Soil salinity affects large areas of the world and results in horticultural and biodiversity losses in tropical regions. Garcinia humilis (Vahl) C.D. Adams, fam. Clusiaceae, commonly known as achachairu, is a neotropical evergreen fruit tree native to the Amazonian forests in Bolivia. Its tolerance and responses to soil salinity exclusive of other stressors and within a range of salinity levels have not been reported. This study assessed the physiological, biochemical, and morphological responses of G. humilis to different levels of elevated soil salinity induced by saline irrigation. Physiological variables measured included net CO₂ assimilation (A_n), stomatal conductance of H₂O (g_s), intercellular CO₂ concentration, leaf chlorophyll index (LCI), and the ratio of variable to maximum chlorophyll fluorescence (F_v/F_m). Leaf and root nutrient analyses were performed to assess nutrient imbalances and the accumulation of toxic ions. Antioxidant responses, including superoxide dismutase, catalase, peroxidase, guaiacol peroxidase, ascorbate peroxidase, ascorbic acid, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione, and glutathione reductase; reactive oxygen species (ROS) such as hydrogen peroxide and superoxide radical; and lipid peroxidation as indicated by malondialdehyde were also measured. The results indicate that G. humilis tolerates elevated soil salinity induced by saline irrigation with an electrical conductivity of at least 6 dS m⁻¹, which results in stress responses without fatal consequences. Soil salinity induced by saline irrigation of 6 dS m⁻¹ reduced A_n and g_s by approximately 50% during a 30-day period, but there was no evidence of physiological damage based on the LCI or F_v/F_m. The levels of Na⁺ and Cl⁻ did not reach toxic levels, and the plants were able to prevent damaging imbalances of plant nutrients, indicating an ion-avoidance strategy. Increased antioxidant response to soil salinity induced by saline irrigation possibly prevented ROS and lipid peroxidation damage. G. humilis appears to be moderately tolerant of soil salinity induced by saline irrigation of at least 30 days at 6 dS m⁻¹. Full article

The Plinia genus comprises an underestimated group of fruit trees native to the neotropics of South and Central America. One such species is Plinia peruviana (Poir.) Govaerts, commonly known as ‘Yvapurú’, which belongs to the Myrtaceae family. Its fruits have high nutraceutical potential and are used in the food and medicinal industries. However, scientific information on its composition and bioactive properties remains limited at the regional level. This study aimed to determine the nutritional composition and antioxidant potential of wild P. peruviana fruits collected in a native forest in Emboscada, Paraguay. Official AOAC methods were employed to analyse the centesimal composition, and the vitamin C content, Total Phenolics Compounds (TPC), and total monomeric anthocyanin (TMA) content were determined in freeze-dried pulp and peel. The main components of whole fruits were total carbohydrates and dietary fibre (12.2 ± 0.7 g/100 g and 9.9 ± 0.8 g/100 g, respectively). The main minerals present were potassium (252 ± 9 mg/100 g), sodium (49 ± 3 mg/100 g), magnesium (46 ± 5 mg/100 g), calcium (21.5 ± 1 mg/100 g) and phosphorus (4.1 ± 0.9 mg/100 g). In terms of antioxidant potential, the peel exhibited higher concentrations of total phenolic compounds (730 ± 5 mg EAG/100 g) and anthocyanins (191 ± 15 mg C3G/100 g) than the pulp (611 ± 13 mg EAG/100 g). These results confirm that P. peruviana fruits have a valuable nutritional profile, providing significant amounts of dietary fibre and essential minerals, as well as high levels of bioactive compounds associated with antioxidant capacity. Using them as a functional food could help prevent chronic diseases and strengthen food security. The study also expands knowledge of Paraguay’s fruit biodiversity and supports the sustainable utilisation of underutilised native species. Full article

Saprotrophic and lignocellulolytic fungi from tropical areas especially represent a promising yet relatively underexplored frontier for both taxonomy and applied research. This makes ex situ conservation through culture collections of paramount importance. Here, 10 lignocellulolytic strains isolated from the State of São Paulo (Brazil) and deposited in the Brazilian Culture Collection (now CCIBt) were identified through the ITS region. In order to prevent accidental losses, these strains have been shared with the collection of the University of Milano—Department of Food, Environmental and Nutritional Sciences (DeFENS), as well as the MicUNIPV Fungal Research Culture Collection—University of Pavia (Italy). Most of the fungal species in the examined set exhibit a neotropical distribution, while 3 out of 10 are nowadays recognized as subcosmopolitan despite their prevalence in the neotropical area. One holotropical, one cosmopolitan and one holarctic species are also present. Based on the literature, 8 out of the 10 characterized species are known to produce psilocybin (e.g., Psilocybe cubensis and Candolleomyces candolleanus) and/or enzymes with potential applications in environmental and medical biotechnology (e.g., Lentinus crinitus). All 10 strains were described for their micro- and macro-characteristics; their growth rate was evaluated and culture pictures provided. Taxonomic and nomenclatural controversies concerning Candolleomyces candolleanus, Cubamyces lactineus and Pycnoporus sanguineus are discussed. Full article