Abstract Introduction: Various anthropic pressures affect the aquatic ecosystems of the foothills of Colombia. The response to environmental stressors is still unknown in bioindicator organisms such as Leptohyphidae. Objective: To determine the diversity of Leptohyphidae nymphs of the Quenane-Quenanito river, in two contrasting hydrological periods and its relationship with some physicochemical variables. Methods: In December (2014) and February (2015), organisms were collected with a Surber net at six stations along the current. Alpha and beta diversity was analyzed and redundancy analysis and generalized linear model were applied to establish the relationship between taxa and environmental variables. Results: Were identified 369 organisms belonging to four genera (Amanahyphes, Traverhyphes, Tricorythopsis, and Tricorythodes), two species, and eight morphospecies. Amanahyphes saguassu is reported for the first time for the Meta department. High diversity of Leptohyphidae nymphs was recorded in the transition to drought season and greater abundance in drought. Beta diversity indicated that the configuration of the assemblage changes spatially and temporally. Conclusions: Leptohyphidae organisms prefer fast habitats, particularly in the dry period where they find food (leaf litter, detritus) and shelter to establish themselves successfully; anthropic activities such as urbanization notably affect diversity. The high diversity recorded in this small river in the foothills of the plains reflects the need to increase this type of works and collection efforts of study material in the region.

Resumen Introducción: Varias presiones antrópicas sufren los ecosistemas acuáticos del piedemonte llanero en Colombia. La respuesta a estresores ambientales aún se desconoce en organismos bioindicadores como Leptohyphidae. Objetivo: Determinar la diversidad de ninfas de Leptohyphidae del río Quenane-Quenanito, en dos periodos hidrológicos contrastantes y su relación con algunas variables fisicoquímicas. Métodos: En diciembre (2014) y febrero (2015) se recolectaron organismos con red Surber en seis estaciones a lo largo del río. Se analizó la diversidad alfa y beta y se aplicó análisis de redundancia y modelos lineales generalizados con el fin de establecer la relación entre los taxones y las variables ambientales. Resultados: Se identificaron 369 organismos pertenecientes a cuatro géneros (Amanahyphes, Traverhyphes, Tricorythopsis y Tricorythodes), dos especies y ocho morfoespecies. Se reporta por primera vez para el departamento del Meta Amanahyphes saguassu. Se registró la mayor diversidad de ninfas en la transición a la sequía y la mayor abundancia en sequía. La diversidad beta señaló que la configuración del ensamblaje cambia a nivel espacial y temporal. Conclusiones: Los organismos de Leptohyphidae prefieren hábitats de corrientes, particularmente en el periodo de sequía, donde hallan alimento (hojarasca, detritos) y refugio para establecerse exitosamente; actividades antrópicas como la urbanización afectan notablemente la diversidad. La alta diversidad registrada en este pequeño río de piedemonte llanero refleja la necesidad de incrementar este tipo de trabajos y esfuerzos de recolección de material de estudio en la región.

Abstract Introduction: Levee forests exhibit a vertical stratification that may contribute to structural complexity allowing a great diversity of birds to thrive on the islands. In deltaic ecosystems there is scarce or no data to prove it. Objectives: To assess variations in the composition of the bird community within levee forests. Methods: Two areas of protected wetlands belonging to the Paraná River Delta in Argentina were sampled for three years. A comparative analysis of richness, abundance, and diversity was performed in different levee forests using the point count method. Results: Three distinct types of levee forests -open, intermediate, and closed- were identified based on the structure of their vegetation, hosting a total of 85 bird species. Variation in avian community structure among forest types revealed greater diversity in open forests during winter (3.26 ± 0.13, P < 0.01) and spring (3.58 ± 0.05, P < 0.01), and greater richness in autumn (35.33 ± 3.01, P < 0.01). The closed forests exhibited increased diversity during autumn (3.16 ± 0.13, P < 0.05) and summer (3.24 ± 0.06, P < 0.05), along with elevated abundance in autumn (114 ± 13.70, P < 0.05) and richness in spring (39.17 ± 4.71, P = 0.01). Due to the evolutionary history between sites, significant variation was observed in the most recently created national park, influencing abundance in winter (141 ± 22.06, P < 0.01) and spring (176 ± 12.83, P < 0.01), as well as diversity in winter (3.25 ± 0.10, P < 0.01) and spring (3.50 ± 0.10, P < 0.01). Conclusions: The microhabitat in the different levee forests allows the birds to organize differently. Focusing on microspatial dynamics is key to a deep understanding of the biological processes within subtropical islands and to plan conservation strategies and demonstrate the transition of a recovering riparian forest towards its natural state, where the pulse of the river and the effect of seasonality do not stop operating.

Resumen Introducción: Los bosques de albardón exhiben una estratificación vertical que puede contribuir en la complejidad estructural, permitiendo que una gran diversidad de aves prospere en las islas. En ecosistemas deltaicos hay escasos datos que lo demuestren. Objetivos: Evaluar las variaciones en la composición de la comunidad de aves dentro de los bosques de albardón. Método: Se muestrearon durante tres años, dos áreas protegidas de humedales pertenecientes al Delta del Río Paraná, Argentina. Se realizó un análisis comparativo de riqueza, abundancia y diversidad de aves en tres diferentes bosques de albardón, utilizando el método de conteo por puntos. Resultados: Tres distintos tipos de bosque de albardón -abiertos, intermedios y cerrados- fueron identificados con base en la estructura de su vegetación, hospedando un total de 85 especies de aves. La variación en la estructura de la comunidad de aves entre tipos de bosque revela mayor diversidad en bosques abiertos durante el invierno (3.26 ± 0.13, P < 0.01) y la primavera (3.58 ± 0.05, P < 0.01), y mayor riqueza en otoño (35.33 ± 3.01, P < 0.01). Los bosques cerrados exhibieron mayor diversidad en el otoño (3.16 ± 0.13, P < 0.05) y en verano (3.24 ± 0.06, P < 0.05), junto con elevada abundancia en otoño (114 ± 13.70, P < 0.05) y elevada riqueza en primavera (39.17 ± 4.71, P=0.01). Debido a la historia evolutiva entre sitios, se observó variación significativa en el parque nacional de más reciente creación, influyendo en la abundancia del invierno (141 ± 22.06, P < 0.01) y de la primavera (176 ± 12.83, P < 0.01), así como en la diversidad en el invierno (3.25 ± 0.10, P < 0.01) y en la primavera (3.50 ± 0.10, P < 0.01). Conclusiones: El microhábitat en los diferentes bosques de albardón permite a las aves organizarse diferencialmente. Enfocarse en la dinámica microespacial es clave para una comprensión profunda de los procesos biológicos dentro de las islas subtropicales, planificar estrategias de conservación y evidenciar la transición de un bosque ripario en recuperación hacia su estado natural, donde el pulso del río y el efecto de la estacionalidad no dejan de operar.

Abstract Introduction: The currents of streams and rivers are natural signals that influence the migrations in the life cycle of amphidromous shrimp. Objective: To evaluate the rheotaxis behavior in juveniles and adults of Macrobrachium tenellum, in relation to their response capacity to different water currentspeeds in a closed-loop experimental system. Methods: A PVC pipe system was used, with a tub for water recirculation and a backwater placed in the middle of the system. Water flows of 10-30 cm/s were tested to establish the experimental conditions. Rheotaxis behavior without backwater (SR) and with backwater (CR) was evaluated; three water flows were tested: FI, 14 cm/s; FII, 18.7 cm/s; and FIII, 22.1 cm/s, and a control FC flow, 0 cm/s, with 40 juveniles, 40 females and 40 males per flow. Three main behaviors were identified: positive rheotaxis, negative rheotaxis, and no reaction. Results: For both SR and CR, water flows stimulate positive rheotaxis and the behavioral response is different depending on the speed of the water flow and whether they are juveniles, females, or males. In CR there was a greater response of the prawns to continue swimming against the current when they entered the pool. At a straight angle, the constant flow of water greater than 23.2 cm/s makes it difficult for this species to swim against the current. Conclusions: The positive rheotaxis response was the most prevalent in juveniles, females, and males of M. tenellum.

Resumen Introducción: Las corrientes de arroyos y ríos son señales naturales que influencian las migraciones en el ciclo de vida de langostinos anfídromos. Objetivo: Evaluar el comportamiento de reotaxis en juveniles y adultos de Macrobrachium tenellum, con relación a su capacidad de respuesta a diferentes velocidades de flujos de corriente de agua en un sistema experimental de circuito cerrado. Métodos: Se utilizó un sistema de tubos PVC, con una tina para la recirculación del agua y un remanso colocado a la mitad del sistema. Se probaron flujos de agua de 10-30 cm/s para establecer las condiciones experimentales. Se evaluó el comportamiento de reotaxis sin remanso (SR) y con el remanso (CR); se probaron tres flujos de agua: FI, 14 cm/s; FII, 18.7 cm/s; y FIII, 22.1 cm/s, y un flujo control FC, 0 cm/s, con 40 juveniles, 40 hembras y 40 machos por flujo. Se identificaron tres comportamientos principales: reotaxis positiva, reotaxis negativa y sin reacción. Resultados: Tanto para SR como CR los flujos de agua estimulan mayormente la reotaxis positiva y la respuesta de comportamiento es diferente según la velocidad del flujo de agua y si son juveniles, hembras o machos. En CR hubo una mayor respuesta de los langostinos a seguir nadando en contra de la corriente cuando estos ingresaban al remanso. En un ángulo recto, el flujo de agua constante superior a 23.2 cm/s dificulta el nado contra corriente de esta especie. Conclusiones: La respuesta de reotaxis positiva fue la que mayor predominó en juveniles, hembras y machos de M. tenellum.

Abstract Introduction: Iron (Fe) and manganese (Mn) are bioessential micronutrients for plants but can impair the energetic metabolism when present at high levels. Objective: To assess the photosynthetic performance and oxidative damages in Rhizophora mangle L. leaf tissues at low and high concentrations of Fe (74 and 195 mg kg-1; Feleaf) and Mn (65 and 414 mg kg-1; Mnleaf). Methods: Photosynthetic pigments, chlorophyll a fluorescence, leaf CO2 assimilation and gas exchange and DPPH• radical scavenging capacity were sampled in R. mangle growing in estuarine forests in the North region of Espírito Santo State and the extreme South of Bahia State (Brazil) showing low and high Feleaf and Mnleaf. Results: Effects of high Fe and Mn were not identified on pigment levels. The increase in Feleaf and Mnleaf at the levels observed in this assessment had a positive effect on the number of reaction centers and on the efficiency of the oxygen-evolving complex, evaluated as K-band, while no changes were found in the parameters related to the excitation trapping efficiency at the active center of photosystem II. Distinct interference patterns of Fe and Mn on the functional processes of photosynthesis were identified, especially on CO2 assimilation and reactive oxygen species metabolism, with major effects on CO2 assimilation and carboxylation efficiency of Rubisco at high Mnleaf. Conclusion: These findings demonstrate the efficiency of R. mangle in positively regulating the electron transport chain in response to high Fe and Mn, at least in terms of the preservation of structure and functionality of the plant photosynthetic apparatus. Moreover, interference of high Mnleaf in R. mangle occurs at non-stomatal and biochemical levels. There is an antagonistic interference of these trace elements with the physiology of R. mangle, which is a dominant species in Brazilian mangroves.

Resumen Introducción: El hierro (Fe) y el manganeso (Mn) son micronutrientes bioesenciales para las plantas, pero pueden afectar el metabolismo energético cuando están presentes en niveles altos. Objetivo: Evaluar el desempeño fotosintético y los daños oxidativos en tejidos foliares de Rhizophora mangle L. a bajas y altas concentraciones de Fe (74 y 195 mg kg-1; Feleaf) y Mn (65 y 414 mg kg-1; Mnleaf). Métodos: Se muestrearon pigmentos fotosintéticos, fluorescencia de clorofila a, asimilación e intercambio de gases de CO2 foliar y capacidad de eliminación de radicales DPPH• en R. mangle que crece en bosques de estuarios en la región Norte del estado de Espírito Santo y el extremo Sur del Estado de Bahía (Brasil) mostrando Feleaf y Mnleaf bajos y altos. Resultados: No se identificaron efectos de niveles elevados de Fe y Mn en los niveles de pigmento. El aumento de Feleaf y Mnleaf en los niveles observados en esta evaluación tuvo un efecto positivo en el número de centros de reacción y en la eficiencia del complejo generador de oxígeno, evaluado como banda K, mientras que no se encontraron cambios en los parámetros relacionados con la eficiencia de atrapamiento de excitación en el centro activo del fotosistema II. Se identificaron distintos patrones de interferencia de Fe y Mn en los procesos funcionales de la fotosíntesis, especialmente en la asimilación de CO2 y el metabolismo de las especies reactivas de oxígeno, con efectos importantes en la asimilación de CO2 y la eficiencia de carboxilación de Rubisco a niveles altos de Mnleaf. Conclusión: Los hallazgos demuestran la eficiencia de R. mangle en la regulación positiva de la cadena de transporte de electrones en respuesta a los altos niveles de Fe y Mn, al menos en términos de preservación de la estructura y funcionalidad del aparato fotosintético de la planta. Además, la interferencia de Mnleaf alto en R. mangle se presenta a niveles no estomáticos y bioquímicos. Hay interferencia antagónica de estos oligoelementos con la fisiología de R. mangle, que es una especie dominante en los manglares brasileños.

Abstract Introduction: The West Indian fruit fly, Anastrepha obliqua (Macquart), is one of the most economically important pests of mangoes in Mexico and the Neotropics. Objective: To analyze adult population patterns of A. obliqua and their relation to local and landscape factors. Methods: We selected 11 “Manila” mango orchards along the middle part of La Antigua River, which were characterized to determine their biophysical structure and landscape configuration considering their distance to six different land uses/land covers. Anastrepha obliqua population was estimated by collecting adult flies in colorless polyethylene plastic bottle traps baited with a protein for three weeks in June 2022. Results: A total of 1 869 adults of A. obliqua were trapped, of which 75 % were females and 25 % were males. Abundance varied from 68 to 490 adult flies per orchard, while capture frequency from 0.36 to 1.8 flies/trap/day. Abundance increased in highly shaded orchards, and capture frequency decreased in orchards with highly soil compaction. Abundance and the frequency of capture increased in orchards near isolated trees of Spondias spp. and decreased in orchards near sugarcane plantations. Shade management in mango orchards may be used as an effective strategy to promote biotic interactions to naturally regulate A. obliqua populations, meanwhile, soil compaction represents a limiting ecological condition, which might severely impact fruit fly larvae survival. Conclusions: Adult population of A. obliqua depends on several local and landscape factors because they indicate resource availability and ecological conditions. These findings could be considered for control strategies in the integrated management of this pest to promote protection and improve the fruit quality of mango crop.

Resumen Introducción: La mosca de las indias occidentales, Anastrepha obliqua (Macquart), es una de las plagas más importantes económicamente en el cultivo de mango de México y el neotrópico. Objetivo: Analizamos los patrones de la población adulta de A. obliqua y su relación con factores locales y del paisaje. Métodos: Un total de 11 huertos de mango “Manila” fueron caracterizados en estructura biofísica y configuración del paisaje. Los adultos de A. obliqua fueron capturados con trampas (botellas de polietileno cebadas con una proteína) durante tres semanas en junio de 2022. Resultados: Se capturaron 1 869 adultos de A. obliqua, de los cuales 75 % fueron hembras y 25 % machos. La abundancia varió de 68 a 490 moscas adultas por huerto, mientras que la frecuencia de captura de 0.36 a 1.8 moscas/trampa/día. La abundancia incrementó en huertos altamente sombreados y decreció en huertos con suelos compactos. La abundancia y frecuencia incrementaron en huertos cercanos a árboles de Spondias spp. y decreció en huertos cercanos a plantaciones de caña de azúcar. El manejo de la sombra puede ser utilizado como una estrategia efectiva para promover las interacciones que regulan naturalmente la población de A. obliqua, mientras que la compactación del suelo representa una condición ecológica limitante que podría impactar severamente en la supervivencia de larvas de moscas de la fruta. Conclusión: La población adulta de A. obliqua depende de varios factores locales y del paisaje que indican disponibilidad de recursos y condiciones ecológicas. Estos hallazgos podrían considerarse en las estrategias del manejo integrado de esta plaga para promover la protección y el mejoramiento de la calidad de frutos en el cultivo de mango.

Abstract Introduction: Acoustic communication is essential in anuran communities, particularly for reproduction. However, the acoustic space is limited, and bioacoustic interferences, such as competition for mating and resources, impact the effectiveness of communication. The tropical dry forest in Colombia hosts resilient anuran species that have endured significant reduction, fragmentation, and transformation over the past decades. The scarce research on this topic underscores the importance of acoustically characterizing anuran assemblages to understand species coexistence, monitor changes in the community, and evaluate the impact of both invasive species and human activity on the ecosystem. Objective: To acoustically characterize an anuran assemblage in the Cauca River Valley. Methods: From September to November 2022 (rainy season), acoustic recordings were obtained using passive and active acoustic sensors from an anuran community in the geographical Cauca River Valley, on the western flank of the Central Cordillera in Colombia. Anuran advertisement calls were analyzed in three dimensions: spectral parameters, temporal patterns, and acoustic activity. Results: Five anuran species were recorded, exhibiting high overlap in activity but significant structural differences in their calls. The species were predominantly nocturnal, except for one from the dendrobatid family. Conclusions: Each species presents a distinct acoustic niche, avoiding overlap in acoustic signals. These findings establish a baseline for assessing future changes in the assemblage.

Resumen Introducción: La comunicación acústica es esencial en las comunidades de anuros, especialmente para la reproducción. No obstante, el espacio acústico es limitado y las interferencias bioacústicas, como la competencia por apareamiento y recursos, afectan la eficacia de la comunicación. El bosque seco tropical en Colombia alberga especies de anuros que han sido resilientes a la gran reducción, fragmentación y transformación de este en las últimas décadas. La investigación escasa en este tema subraya la importancia de la caracterización acústica de los ensamblajes de anuros, para comprender la coexistencia de especies, monitorear cambios en la comunidad y evaluar el impacto tanto de especies invasoras como de la actividad humana en el ecosistema. Objetivo: Caracterizar acústicamente un ensamblaje de anuros del valle del río Cauca. Métodos: De septiembre a noviembre de 2022 (temporada lluviosa), se tomaron registros acústicos con sensores acústicos pasivos y activos de una comunidad de anuros del valle geográfico del río Cauca, en el flanco occidental de la cordillera central de Colombia. Se analizaron los cantos de anuncio en tres dimensiones: parámetros espectrales, temporales y patrones de actividad acústica. Resultados: Se registraron cinco especies de anuros, sus cantos presentaron un alto solapamiento en actividad, pero grandes diferencias estructurales, las especies tuvieron actividad nocturna a excepción de una de la familia Dendrobatidae. Conclusiones: Cada especie presenta un nicho acústico particular que evita el traslape en las señales acústicas, y estos resultados proporcionan una línea base para evaluar futuros cambios en el ensamblaje.

Abstract Introduction: The Family Chironomidae is recognized for its great abundance and diversity in freshwater ecosystems around the world. However, taxonomic knowledge of this family is limited, particularly in Colombia. Objectives: To estimate the abundance and diversity at the genus level and its spatiotemporal dynamics in three streams, tributaries of the Combeima River in central Colombia. Methods: This study describes the taxonomic and ecological evaluation of chironomid larvae present in three high Andean streams (Tolima, Colombia), called Las Perlas (PE), La Plata (PL) and Cay (CA). Between 2015-2016, six sampling campaigns were conducted in contrasting climatic periods, at nine sampling points (three per stream: upper, middle, and lower). The collections were made with Surber net on different substrates. Results: 15 594 larvae were recorded, corresponding to three subfamilies and 20 genera. The most abundant subfamily was Orthocladiinae with 13 698 larvae (87.84 %), dominated by Cricotopus spp. (66.19 %), followed by Chironominae with 1 367 individuals (8.77 %) and Polypedilum spp. (5.18 %), and Tanypodinae with 530 organisms (3.40 %) and Pentaneura spp. (2.91 %). The highest abundance was found in PL3 (lower part; 27.84 %), followed by CA2 (middle part; 20.47 %) and PE1 (upper part; 1.93 %). The three streams presented the highest abundance during February 2016 (25.93 %; transition to the rainy season), followed by November 2015 (20.59 %; low rainfall) and October 2015 (3.94 %; high rainfall). Conclusions: The results obtained expands the taxonomic lists of chironomids in high Andean areas (1 419-2 586 m), and the detailed characterization of the 20 genera recorded in the selected streams, which constitute relevant contributions for the recognition of these dipterans and their ecological role in the aquatic systems of the Colombian Andes.

Resumen Introducción: La Familia Chironomidae es reconocida por su gran abundancia y diversidad en los ecosistemas de agua dulce alrededor del mundo. Sin embargo, el conocimiento taxonómico de esta familia es limitado, particularmente en Colombia. Objetivos: Estimar la abundancia y diversidad a nivel de género de la Familia Chironomidae y su dinámica espacio-temporal en tres quebradas, afluentes del Río Combeima en el centro de Colombia. Métodos: Este estudio describe la evaluación taxonómica y ecológica de las larvas de quironómidos presentes en tres quebradas altoandinas (Tolima, Colombia), denominadas Las Perlas (PE), La Plata (PL) y Cay (CA). Entre 2015-2016 se realizaron seis campañas de muestreo en periodos climáticos contrastantes, en nueve puntos de muestreo (tres por quebrada: parte alta, media, y baja). Las recolectas se realizaron con red Surber en diferentes sustratos. Resultados: Se registraron 15 594 larvas, correspondientes a tres subfamilias y 20 géneros. La más abundante fue Orthocladiinae con 13 698 larvas (87.84 %), dominada por Cricotopus spp. (66.19 %), seguida de Chironominae con 1 367 individuos (8.77 %) y Polypedilum spp. (5.18 %), y Tanypodinae con 530 organismos (3.40 %) y Pentaneura spp. (2.91 %). La mayor abundancia se encontró en PL3 (parte baja; 27.84 %), seguido de CA2 (parte media; 20.47 %) y PE1 (parte alta; 1.93 %). Las tres quebradas presentaron la mayor abundancia durante febrero 2016 (25.93 %; transición a la época de lluvias), seguido de noviembre 2015 (20.59 %; precipitaciones bajas) y octubre 2015 (3.94 %; precipitaciones altas). Conclusiones: Los resultados obtenidos amplían las listas taxonómicas de quironómidos en zonas altoandinas (1 419-2 586 m), y la caracterización detallada de los 20 géneros registrados en las quebradas seleccionadas, que constituyen aportes relevantes para el reconocimiento de estos dípteros y su rol ecológico en los sistemas acuáticos de los Andes colombianos.

Abstract Introduction: The River Tambo basin is one of the main hydrographic systems of the Peruvian western watershed, being a source of development for agriculture, agroindustry, livestock, and domestic use in the Tambo Valley and Arequipa City. Objective: To analyze the structure of macroinvertebrates in River Tambo, Perú and assess the water quality through this community. Methods: Five sampling events were conducted between December 2018 and November 2019 in 12 stations, using a Surber net (500 μm). Macroinvertebrates were identified at a family level. To assess community structure, richness, Simpson’s dominance index (D), Pielou’s evenness (J’), and true diversity of order 1 were determined. A nMDS based on the Bray-Curtis index was used to evaluate dissimilarity. To check for differences in community structure, ANOSIM and two-way MANOVA were used. SIMPER was used to establish family contribution to sample similarity. Relations between physicochemical and biological variables were determined by CCA. ABI index was applied to assess ecological quality. Results: 32 families were recognized, being the most abundant: Baetidae, Chironomidae, Leptohyphidae, Simuliidae, Hydroptilidae, and Elmidae. The middle and low zones of the basin showed the highest and lowest diversity respectively. There were significant differences (P < 0.05) in the community structure indices among the 12 stations differed. There was a higher similarity among the 12 stations in December. ABI scores increased from the low to the middle part of the river, which showed the highest ecological quality. Conclusion: Macroinvertebrate communities from River Tambo reflect ecosystem conditions. Environments impacted by human activities show lower diversity and ecological quality, due to the structure, habitat, and water quality of the river being altered.

Resumen Introducción: La cuenca del rio Tambo es uno de los principales sistemas hidrográficos de la vertiente occidental del Perú y fuente de desarrollo para la agricultura, agroindustria, ganadería y consumo doméstico en el valle de Tambo y la ciudad de Arequipa. Objetivo: Analizar la estructura de macroinvertebrados en el río Tambo, Perú y evaluar la calidad del agua a través de esta comunidad. Métodos: Entre diciembre del 2018 y noviembre del 2019 se realizaron cinco muestreos en 12 estaciones, empleando una red Surber (500 μm). Los macroinvertebrados se identificaron a nivel de familia. Se registró la riqueza, dominancia de Simpson, equidad de Pielou, y diversidad verdadera de orden 1, para evaluar la estructura de la comunidad. Para estimar la similitud, se utilizó nMDS (índice de Bray-Curtis). Para verificar si existen diferencias en la estructura comunitaria, se empleó MANOVA de dos vías y ANOSIM. Para establecer la contribución de las familias a la similitud entre muestras, se utilizó SIMPER. La relación entre variables fisicoquímicas y biológicas se determinó con ACC. Se aplicó el índice ABI para evaluar la calidad ecológica. Resultados: se reconocieron 32 familias, siendo las más abundantes: Baetidae, Chironomidae, Leptohyphidae, Simuliidae, Hydroptilidae y Elmidae. La mayor y menor diversidad se presentó en la parte media y baja de la cuenca respectivamente. Existieron diferencias significativas (P < 0.05) de los índices de estructura comunitaria entre las 12 estaciones. Se evidenció mayor similitud entre las 12 estaciones en diciembre. Los puntajes del índice ABI se incrementan de la parte baja del río a la media, que se presentó la mejor calidad ecológica. Conclusión: Las comunidades de macroinvertebrados del río Tambo reflejan el estado del ecosistema. Los ambientes con impacto por actividad humana registran menor diversidad y calidad ecológica, ya que se altera la estructura, hábitat y calidad de agua del río.

Abstract Introduction: Macrobrachium amazonicum is widely distributed in South America, occurring in the Orinoco, Amazon and Paraguay river basins, being used as an important source of protein for feeding riverside populations. This prawn is host to the crustacean ectoparasites Probopyrus pandalicola, Probopyrus floridensis and Probopyrus bithynis (Bopyridae) that infest the gill cavity of the species. Objective: To report the prevalence and abundance of ectopasites (P. pandalicola, P. floridensis and P. bithynis) and the condition factor in M. amazonicum from the Amazon River, Eastern Amazon. Methods: The prawns were collected from May 2017 to April 2018, with the artisanal trap matapi in the municipalities of Mazagão (state of Amapá) and Santarém (state of Pará), Brazil. Results: 216 prawns infected with ectoparasites were captured, 133 in the Mazagão region (53 P. pandalicola, 48 P. bithynis and 32 P. floridensis) and 83 in the Santarém region (45 P. pandalicola and 38 P. bithynis). In Mazagão, the highest prevalence values were recorded in May (1.98 %) for P. floridensis, July (2.18 %) for P. bithynis, and March (1.93 %) for P. pandalicola. In the Santarém region, the highest prevalence values were recorded in February, 3.47 for P. pandalicola and 2.89 for P. bithynis. Regarding the abundance of parasites, there was no difference between the species grouped between the regions (t = 0.32, p = 0.739). Parasitized prawns from Mazagão and Santarém presented condition factors below expectations, with an average of 0.85 ± 0.55 for Santarém and 0.88 ± 0.44 for Mazagão. Conclusions: During the study it was found that P. pandalicola, P. bithynis and P. floridensis were present in M. amazonicum throughout the year. Furthermore, there was an effect of parasitism on M. amazonicum in the study areas.

Resumen Introducción: Macrobrachium amazonicum está ampliamente distribuido en América del Sur, se encuentra en las cuencas de los ríos Orinoco, Amazonas y Paraguay, se utiliza como una fuente importante de proteínas para alimentar a las poblaciones ribereñas. Este camarón es hospedero de los ectoparásitos crustáceos: Probopyrus pandalicola, Probopyrus floridensis y Probopyrus bithynis (Bopyridae), que infestan la cavidad branquial de la especie. Objetivo: Reportar la prevalencia y abundancia de ectoparásitos (P. pandalicola, P. floridensis y P. bithynis) y el factor de condición de M. amazonicum en el| río Amazonas, al este de la Amazonía. Métodos: Los camarones fueron recolectados entre mayo 2017 y abril 2018, con la ayuda de matapis (trampa artesanal) en los municipios de Mazagão (Estado de Amapá) y Santarém (Estado de Pará), Brasil. Resultados: Se capturaron un total de 216 camarones parasitados con ectoparásitos, 133 de ellos en la región de Mazagão (53 P. pandalicola, 48 P. bithynis y 32 P. floridensis) y 83 en la región de Santarém (45 P. pandalicola y 38 P. bithynis). En Mazagão, los valores más altos de prevalencia se registraron en mayo (1.98 %) para P. floridensis, julio (2.18 %) para P. bithynis y marzo (1.93 %) para P. pandalicola. En la región de Santarém, los valores más altos de prevalencia se registraron en febrero, de 3.47 para P. pandalicola y 2.89 para P. bithynis. En cuanto a la abundancia de parásitos, no hubo diferencia entre las especies agrupadas entre las regiones (t = 0.32, p = 0.739). Los camarones parasitados de Mazagão y Santarém mostraron factores de condición por debajo de lo esperado, con un promedio de 0.85 ± 0.55 para Santarém y 0.88 ± 0.44 para Mazagão. Conclusiones: Durante el estudio, se encontró que P. pandalicola, P. bithynis y P. floridensis estuvieron presentes en M. Amazonicum todo el año. Además, hubo un efecto de parasitismo sobre M. Amazonicum en las áreas de estudio.

ABSTRACT The present study aimed to evaluate the ecology considering distribution, abundance, population structure, and fecundity of the marine diplostraceans Penilia avirostris and Pseudevadne tergestina in the Veracruz Reef System National Park, southwest Gulf of Mexico. Surface samples were collected with a 300 μm mesh plankton net at 26 sampling sites in June, August, October (2011), May (2012) and June (2013). Temperature, salinity, and dissolved oxygen were measured in situ. The temperature range was 26.53 ± 0.41 and 29.29 ± 0.27°C, salinity between 33.43 ± 0.49 and 35.91 ± 0.09, and dissolved oxygen between 2.92 ± 0.08 and 6.56 ± 0.08 mg L-1. P. avirostris and P. tergestina presented the highest density, with 2200 ind 100 m-3 in June and 5980 ind 100 m-3 in October, respectively. Four stages were determined in P. avirostris. In P. tergestina, there were five instars, with males in August and October. The size of parthenogenic females of P. avirostris was 773.4 ± 20.08 μm. In P. tergestina, it was 637.6 ± 49.28 μm. The number of embryos in P. avirostris was 2 to 7, and in P. tergestina, 2 to 8 embryos. The correlations between body length and the number of embryos in both species were statistically significant under the potential model (r > 0.68 for both species, P < 0.001). The transects with the highest abundance were the northern and the southern zones because they are far from the influence of the Jamapa River. The density of these crustaceans is related to optimal temperature, salinity, and dissolved oxygen values. The low proportions obtained from gamogenic individuals of P. avirostris and P. tergestina suggest that in tropical and subtropical regions, gamogenesis is not crucial for the life cycle of these organisms.

ABSTRACT Amazonia (defined herein as the Amazon basin) is home to the greatest concentration of biodiversity on Earth, providing unique genetic resources and ecological functions that contribute to ecosystem services globally. The lengthy and complex evolutionary history of this region has produced heterogeneous landscapes and riverscapes at multiple scales, altered the geographic and genetic connections among populations, and impacted rates of adaptation, speciation, and extinction. In turn, ecologically diverse Amazonian biotas promoted further diversification, species coexistence, and coevolution, with biodiversity accumulating over tens of millions of years. Important events in Amazonian history included: (i) late Cretaceous and early Paleogene origin of major rainforest plant and animal groups; (ii) Eocene-Oligocene global cooling with rainforests contracting to tropical latitudes separating Atlantic coastal and Amazonian rainforests; (iii) Miocene uplift of central and northern Andes that separated Pacific coastal and Amazonian rainforests, spurred formation of mega-wetlands in the western Amazon, and contributed to the origin of the modern transcontinental Amazon River; (iv) late Neogene formation of the Panamanian Isthmus that facilitated the Great American Biotic Interchange; (v) Pleistocene climate oscillations followed by late Pleistocene-Holocene human colonization and megafaunal extinctions; and (vi) modern era of widespread anthropogenic deforestation, defaunation, and ecological transformations of regional landscapes and global climates. Amazonian conservation requires decade-scale investments into biodiversity documentation and monitoring to leverage existing scientific capacity, and strategic habitat planning to allow continuity of evolutionary and ecological processes now and into the future. defined basin Earth globally scales populations adaptation speciation extinction turn diversification coexistence coevolution years included i (i groups ii (ii EoceneOligocene Eocene Oligocene iii (iii megawetlands mega wetlands River iv (iv Interchange v (v PleistoceneHolocene Holocene extinctions vi (vi deforestation defaunation climates decadescale decade scale capacity future

RESUMEN La Amazonía (definida como la cuenca amazónica) concentra la mayor biodiversidad de la Tierra, proporcionando recursos genéticos y funciones ecológicas únicas que contribuyen a los servicios ecosistémicos a nivel mundial. La compleja historia evolutiva de esta región produjo paisajes heterogéneos a múltiples escalas geográficas, alteró las conexiones geográficas y genéticas entre las poblaciones e influyó en las tasas de adaptación, especiación y extinción. Las biotas amazónicas, ecológicamente diversas, promovieron una mayor diversificación, coexistencia de especies y coevolución, acumulando biodiversidad a lo largo de decenas de millones de años. Acontecimientos importantes en la historia de la Amazonía incluyeron: (i) orígenes durante el Cretácico tardío y el Paleógeno temprano de los principales grupos de plantas y animales; (ii) enfriamiento global del Eoceno-Oligoceno, contrayendo los bosques a latitudes tropicales y separando los de la costa Atlántica de los amazónicos; (iii) levantamiento de los Andes centrales y del norte en el Mioceno, separando las selvas tropicales de la costa del Pacífico y de la Amazonía, estimulando la formación de megahumedales en la Amazonía occidental y contribuyendo al origen del moderno Río Amazonas transcontinental; (iv) formación del istmo de Panamá durante el Neógeno tardío, facilitando el Gran Intercambio Biótico Americano; (v) oscilaciones climáticas del Pleistoceno seguidas por la colonización humana y las extinciones de megafauna; (vi) era moderna de deforestación antropogénica generalizada, defaunación y transformaciones ecológicas de paisajes regionales y climas globales. La conservación de la Amazonía requiere inversiones por décadas en la documentación y el seguimiento de la biodiversidad para impulsar la capacidad científica existente, así como la planificación estratégica del hábitat para permitir la continuidad de los actuales y futuros procesos evolutivos y ecológicos. definida amazónica Tierra mundial adaptación extinción amazónicas diversas diversificación coevolución años incluyeron i (i animales ii (ii EocenoOligoceno, EocenoOligoceno Eoceno Oligoceno, Oligoceno Eoceno-Oligoceno amazónicos iii (iii Mioceno transcontinental iv (iv Americano v (v megafauna vi (vi generalizada globales existente ecológicos

ABSTRACT The collapse of the Fundão Dam in Mariana, MG, in 2015 introduced the challenge of using Technosol, a soil type formed by deposition of iron mining waste along the Doce River banks, for agricultural purposes. This study aimed to determine the optimal water depth for enhancing production of tropical forage, Megathyrsus maximus cv. Mombasa, when grown on iron ore tailings. Additionally, it sought to establish a crop coefficient applicable to the edaphoclimatic conditions of Viçosa, MG, Brazil. The experiment was conducted throughout the summer, fall, and winter of 2022, employing 21 drainage lysimeters. A completely randomized experimental design was adopted, featuring six treatment groups (plants in Technosol receiving water depths ranging from 20 to 120% of the crop’s evapotranspiration, as derived from the control treatment), along with a control group (plants in Latosol with a depth of 100%), each with three repetitions. Our findings showed that irrigation must replace 40% of the crop evapotranspiration. Moreover, cultivating in Technosol resulted in a reduction of productive capacity by 37.39% during the summer/fall and fall seasons. For Mombasa grass grown in Oxisol, crop coefficients of 1.2 during the summer and 1.5 during the fall and winter are advised. Mariana MG 201 banks purposes forage cv tailings Additionally Viçosa Brazil 2022 2 lysimeters adopted plants 120 crops s evapotranspiration treatment, , treatment) 100%, 100 100% 100%) repetitions 40 Moreover 3739 37 39 37.39 summerfall seasons Oxisol 12 1 1. 15 5 advised 202 10 4 373 3 37.3 37.

RESUMO O rompimento da Barragem do Fundão em Mariana, MG, ocorrida em 2015, trouxe o desafio de usar o Tecnossolo (tipo de solo) formado pela deposição do rejeito de mineração de ferro nas margens do Rio Doce para agricultura. O objetivo desta pesquisa foi obter a lâmina de água para otimizar a produção da forragem tropical Megathyrsus maximum cv. Mombaça, cultivada em rejeito de mineração de ferro e determinar seu coeficiente de cultura para as condições edafoclimáticas de Viçosa, MG. O experimento foi realizado durante as estações de verão, outono e inverno do ano de 2022, com a utilização de 21 lisímetros de drenagem. O experimento foi distribuído em delineamento inteiramente casualizado com 6 tratamentos (plantas em Tecnossolo com lâminas variando de 20 a 120% da evapotranspiração da cultura, obtida do tratamento-testemunha) e adição de uma testemunha (plantas em Latossolo com lâmina de 100%) com três repetições. Recomenda-se irrigação com reposição de 40% da evapotranspiração da cultura. O cultivo em Tecnossolo diminuiu a capacidade produtiva em 37,39% nos ciclos das estações do verão/outono e outono. Recomenda-se os coeficientes de cultura de 1,2 no verão e 1,5 no outono e no inverno, para o capim-Mombaça cultivado em um Latossolo. Mariana MG 2015 tipo solo agricultura cv Mombaça Viçosa 2022 2 drenagem plantas 120 tratamentotestemunha tratamento tratamento-testemunha 100% 100 repetições Recomendase Recomenda se 40 3739 37 39 37,39 verãooutono 12 1 1, 15 5 capimMombaça capim 201 202 10 4 373 3 37,3 37,

ABSTRACT Background: The riverine communities of the Amazon comprise different social groups that inhabit the rural areas on the banks of rivers and lakes. Residents usually travel by river to rural and urban areas and are then exposed to urbanized diseases such as those caused by arbovirus infection. In Brazil, emerging diseases such as dengue, Zika, chikungunya, and those caused by infection with Oropouche and Mayaro viruses necessitate epidemiological surveillance. This study was aimed at determining the frequency of positivity for immunoglobulin (Ig)G and IgM antibodies against Zika, chikungunya, and dengue viruses and performing molecular analyses to detect viral RNA for the Zika, chikungunya, dengue virus, Oropouche, and Mayaro viruses, in the same serum samples obtained from riverside populations. Methods: This cross-sectional study was conducted in a riverside population in the Humaitá municipality of the Brazilian Amazon. More than 80% of the local population participated in this study. Entomological samples were collected to identify local mosquito vectors. Results: Analysis of 205 human serological samples revealed IgG antibodies against the dengue virus in 85 individuals. No molecular positivity was observed in human samples. Entomological analyses revealed 3,187 Diptera species, with Mansonia being the most frequent genus. Aedes aegypti and Aedes albopictus were not detected in the two collections. Conclusions: IgG antibodies against the dengue virus were highly prevalent, suggesting previous exposure. The absence of the arbovirus vectors Aedes aegypti and Aedes albopictus in the samples supports the hypothesis that the infections recorded likely occurred outside the riverside communities investigated. Background lakes Brazil Zika chikungunya surveillance Ig G populations Methods crosssectional cross sectional 80 Results 20 8 individuals 3187 3 187 3,18 species genus collections Conclusions prevalent exposure investigated 2 318 18 3,1 31 1 3,

ABSTRACT We report a case of eosinophilic meningitis associated with the ingestion of raw fish (Cichla sp.) from the Brazilian Amazon, likely caused by Gnathostoma. A 36-year-old male visited Juruena river on a fishing trip. After 50 days, the patient presented with an intense frontal headache. A cerebrospinal fluid examination revealed 63% eosinophilia. Another individual who ingested raw fish developed linear dermatitis on the abdominal wall. Anti-Gnathostoma serum antibodies were detected, and the patient made a full recovery after treatment with corticosteroids and albendazole. To date, autochthonous Gnathostoma spp. infections in Latin American countries have only caused linear panniculitis. This report raises awareness of gnathostomiasis-causing meningitis. Cichla sp. sp Amazon 36yearold yearold 36 year old trip 5 days headache 63 eosinophilia wall AntiGnathostoma Anti detected albendazole date spp panniculitis gnathostomiasiscausing gnathostomiasis causing 3 6

ABSTRACT Extended-spectrum beta-lactamase producing and ciprofloxacin-non-susceptible Escherichia coli are clinical and environmental issues. We evaluated the susceptibility profile of fosfomycin in non-susceptible E. coli isolated from urine and the environment. We measured the activity of fosfomycin against 319 and 36 E. coli strains from urine and environmental isolates, respectively, collected from rivers. Fosfomycin resistance profiles were investigated using the minimal inhibitory concentration (MIC), according to the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) guidelines. Antibiotic susceptibility testing revealed that 5% and 6.6% of urine samples were non-susceptible to fosfomycin according to CLSI and EUCAST guidelines, respectively. The fosfomycin MIC50/90 was 0.5/4 mg/L. Of the 36 E. coli isolates from river water, 11.1% and 13,8% were non-susceptible to fosfomycin according to CLSI and EUCAST, respectively (range ≤0.25 ≥512 mg/L). All the isolates with MIC ≥512 mg/L for fosfomycin showed the fosA3 gene. Fosfomycin resistance was more frequent in the environment than in clinical samples. Extendedspectrum Extended spectrum betalactamase beta lactamase ciprofloxacinnonsusceptible ciprofloxacin non susceptible issues nonsusceptible E 31 3 rivers MIC, , (MIC) (CLSI (EUCAST guidelines 5 66 6 6.6 MIC5090 MIC50 90 MIC50/9 054 0 4 0.5/ mgL mg L water 111 11 1 11.1 138 13 8 13,8 range 025 25 ≤0.2 512 ≥51 . mg/L) fosA gene (MIC 6. MIC509 MIC5 9 MIC50/ 05 0.5 11. 13, 02 2 ≤0. 51 ≥5 0. ≤0 ≥ ≤