Resumo O gênero Amblyomma (Arachnida: Ixodidae) é amplamente distribuído na América do Sul, com 34 espécies ocorrendo no Brasil. Amblyomma nodosum Neumann 1889 é uma espécie que se alimenta predominantemente de Passeriformes, durante os estágios imaturos (larvas e ninfas), e de tamanduás (Myrmecophagidae) durante os estágios adultos. O objetivo do presente estudo é relatar, pela primeira vez, um caso incomum de parasitismo por adultos de A. nodosum em um Sapo-cururu (Rhinella icterica), capturado na cidade de Nossa Senhora da Glória, estado de Sergipe (Nordeste do Brasil) na Caatinga, e também investigar a presença de DNA de Rickettsia no material coletado. DNA foi extraído de todos os espécimes (N=8) coletados e submetidos a ensaios de cPCR baseados no gene endógeno 16S rRNA de carrapatos e no gene gltA de Rickettsia sp. Todas as amostras (8/8; 100%) foram positivas para o gene endógeno 16S rRNA e dois amplicons (obtidos de um macho e uma fêmea) foram purificados e sequenciados. A análise BLASTn das sequências revelou um alto grau de similaridade (95-100%) com sequências de A. nodosum previamente depositadas no GenBank, enquanto a análise filogenética agrupou as sequências obtidas no mesmo clado das sequências de A. nodosum do Brasil. Arachnida (Arachnida Ixodidae Sul 3 Brasil 188 Passeriformes larvas ninfas, ninfas , ninfas) Myrmecophagidae (Myrmecophagidae relatar vez Sapocururu Sapo cururu Rhinella icterica, icterica icterica) Glória Nordeste Caatinga coletado N=8 N8 N 8 (N=8 S sp 8/8 88 (8/8 100% 100 obtidos fêmea sequenciados 95100% 95100 95 (95-100% GenBank 18 N= (N= 8/ (8/ 10 9510 9 (95-100 1 (N (8 951 (95-10 ( (95-1 (95- (95 (9

Abstract The Amblyomma genus (Arachnida: Ixodidae) is widely distributed in South America, with 34 species occurring in Brazil. Amblyomma nodosum Neumann 1889 is a species that predominantly feeds on Passeriformes during immature stages (larvae and nymphs) and anteaters (Myrmecophagidae) during adult stages. The aim of the present study is to report, for the first time, an unusual case of parasitism by adults of A. nodosum on a yellow cururu toad (Rhinella icterica) captured in the city of Nossa Senhora da Glória, Sergipe state (Northeastern Brazil) in the Caatinga biome, and also investigate the presence of DNA of Rickettsia in the collected material. DNA was extracted from all specimens collected (N=8) and subjected to PCR assays based on the tick 16S rRNA endogenous gene and gltA gene for Rickettsia sp. All samples (8/8; 100%) were positive for the 16S rRNA endogenous gene and two amplicons (obtained from one male and one female) were purified and sequenced. The BLASTn analysis of the sequences revealed a high degree of similarity (95-100%) with A. nodosum sequences previously deposited on GenBank, while the phylogenetic analysis clustered the sequences obtained in the same clade as A. nodosum sequences from Brazil. Arachnida (Arachnida Ixodidae America 3 Brazil 188 larvae nymphs Myrmecophagidae (Myrmecophagidae report time A Rhinella icterica Glória Northeastern biome material N=8 N8 N 8 (N=8 S sp 8/8 88 (8/8 100% 100 female sequenced 95100% 95100 95 (95-100% GenBank 18 N= (N= 8/ (8/ 10 9510 9 (95-100 1 (N (8 951 (95-10 ( (95-1 (95- (95 (9

Resumen Introducción: El uso frecuente de plaguicidas es considerado actualmente una causa de contaminación ambiental debido a las altas tasas de ingreso de estas sustancias a los agroecosistemas. Esta situación es un riesgo para las especies que habitan en estos ecosistemas, en particular los anuros cuyas características los hacen propensos a la exposición e interacción con contaminantes ambientales. Objetivo: Informar la presencia de anormalidades en larvas del sapo común Rhinella arenarum que habitan en estanques rodeados por un agroecosistema. Métodos: En dos primaveras consecutivas (2015 y 2016), se monitorearon los eventos reproductivos del sapo común proveniente de sistemas de estanques temporales ubicados en zonas agrícolas y no agrícolas, cerca de la ciudad de La Plata (Buenos Aires, Argentina). Se midieron los parámetros fisicoquímicos de los estanques y se registraron las etapas de cada evento reproductivo como el número de sapos adultos, amplexos y nidadas. En el laboratorio, las larvas fueron medidas y fotografiadas, se registró su estado de desarrollo y se examinó la morfología de cada una bajo microscopio estereoscópico. Se procesaron muestras representativas (normales y anormales) de cada estanque estudiado para análisis histopatológico. Resultados: En la población de R. arenarum que vive dentro de un agroecosistema, se observó un menor número de adultos reproductores y puestas en relación con la del estanque en la zona no agrícola. Se recolectaron un total de 1 910 larvas: 529 y 1 381 larvas de estanques ubicados en zonas no agrícolas y agrícolas, respectivamente. Las larvas del agroecosistema mostraron dos tipos de anormalidades: severa flexión de la cola y distensión abdominal. Además, se pudo determinar cinco grados de gravedad en relación con la distensión abdominal. Conclusiones: Una alta frecuencia y severidad de anormalidades en los estadios tempranos de larvas de R. arenarum que viven dentro de un agroecosistema proporciona evidencia del impacto negativo que las actividades agrícolas causan en los ecosistemas acuáticos rodeados por áreas de cultivo.

Abstract Introduction: The frequent use of pesticides is currently considered a cause of environmental pollution due to the high rate of entry of these substances into agroecosystems. This constitutes a risk for the species that inhabit these ecosystems, in particular anurans whose characteristics make them prone to exposure to and interaction with environmental pollutants. Objective: To report the occurrence of abnormalities in larvae of the common toad Rhinella arenarum inhabiting ponds surrounded by agroecosystems. Methods: In two consecutive springs (2015 and 2016), reproductive events of common toads were monitored in temporary pond systems in agricultural and non-agricultural areas, located near the city of La Plata (Buenos Aires, Argentina). The physicochemical parameters of the ponds were measured, and the stage of each reproductive event was recorded, such as the numbers of adult toads, amplexus and clutches. In the laboratory, the larvae were measured and photographed, their stage of development was recorded, and their morphology was examined under a stereomicroscope. Representative samples (normal and abnormal) from each pond studied were processed for histopathological analysis. Results: In the field studies carried out on a population of R. arenarum collected in an agroecosystem, a lower number of reproductive adults and clutches were observed in relation to the population of a non-agricultural pond. A total of 1 910 larvae were collected: 529 and 1 381 larvae from ponds located in non-agricultural and agricultural areas, respectively. Larvae from the agroecosystem showed two types of abnormalities: severe tail flexure and abdominal bloating. In addition, five degrees of severity could be determined in relation to abdominal bloating. Conclusions: This work reports the high frequency and severity of abnormalities observed in the early stages of R. arenarum larvae living within an agroecosystem, providing evidence of the negative impact that agricultural activities cause on aquatic ecosystems surrounded by farming areas.

Toads of the Rhinella genus have a pair of paratoid glands that store biological secretions of high toxicity and varied chemical composition, rich in biologically active compounds. The present work aimed to carry out the investigation of the metabolomic profile and evaluation of the biological potential of the secretion paratoid glands (PGS) from Rhinella granulosa. The paratoid secretion was collected in the Piauí state (Brazil), extracted with methanol and the extract was analyzed by ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry. Fifty chemical constituents were identified. The extract showed cytotoxicity against tumor cell lines of the central nervous system (half maximal inhibitory concentration (IC50) = 1.9 µg mL-1) and prostate (IC50 = 1.6 µg mL-1), unsatisfactory antimicrobial potential (minimal inhibitory concentration (MIC) > 312 µg mL-1) and inhibited the enzyme acetylcholinesterase (IC50 = 5.119 mg mL-1). The results presented relevant information about the PGS and contributed to the understanding of the metabolomic and biological potential of R. granulosa. composition compounds (PGS granulosa Brazil, Brazil , (Brazil) ultraperformance ultra performance timeofflight time flight spectrometry identified half IC50 IC 19 1 9 1. mL1 mL mL-1 (IC5 16 6 mL1, minimal MIC (MIC 31 5119 5 119 5.11 mL1. . R (Brazil IC5 mL- (IC 3 511 11 5.1 51 5.

Resumen La alta carga de agroquímicos y antibióticos en los ambientes acuáticos y los agroe-cosistemas representa un riesgo para la vida silvestre. Dado que la microbiota intestinal juega un papel fundamental en el funcionamiento de su hospedador y es sensible a una amplia variedad de contaminantes, su estudio permite evaluar la salud de los organismos. En este trabajo estudiamos los efectos de formulaciones comerciales de un herbicida a base de glifosato (GBH) y del antibiótico ciprofloxacina (CIP), por separado y en mezcla, sobre la diversidad de bacterias intestinales de renacuajos del sapo común (Rhinella arenarum). El estudio de la diversidad de bacterias entéricas cultivables de rápido crecimiento y bajo requerimiento nutricional se llevó a cabo utilizando pruebas microbiológicas clásicas e identificación por espectrometría de masas de tiempo de vuelo por desorción/ionización láser asistida por matriz (MALDI-TOF). La microbiota entérica fue diferente según el tratamiento. El GBH indujo un aumento de la diversidad bacteriana, mientras que la CIP produjo una reducción. Entre estos cambios, destaca la presencia de Yersinia spp. y Proteus spp. solo en el tratamiento con GBH. Además, en el tratamiento GBH-CIP se encontró una disminución en la prevalencia de Klebsiella spp. y Pseudomonas spp. en la microbiota intestinal de los renacuajos. Este es el primer informe sobre la alteración del contenido bacteriano intestinal de renacuajos de R. arenarum producido por dos contaminantes emergentes de preocupación. Demostramos que el renacuajo del sapo común se puede utilizar como un organismo modelo no convencional para el monitoreo de la contaminación ambiental. Estos hallazgos constituyen el primer paso para comprender cómo la presencia de GBH y CIP en aguas dulces puede representar una amenaza para la vida silvestre y la salud humana a través de la disbiosis entérica asociada al efecto sobre la comunidad bacteriana.

Abstract The high load of agrochemicals and antibiotics present in agricultural aquatic environments represents a risk for wildlife. Since enteric bacteria, which play a key role in the physiological functioning of their hosts, are sensitive to a wide variety of pollutants, their study allows to evaluate the health of organisms. This study aimed to evaluate the effects of commercial formulations of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP), individually and in mixture, on the bacterial diversity of the intestinal content of common toad (Rhinella arenarum) tadpoles. The diversity of cultivable fast-growing bacteria with low nutritional requirements was evaluated using classic microbiological tests and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identification. Bacterial diversity varied among treatments. Taxa diversity increased in the GBH-treated group but decreased in the CIP-treated group. Remarkably, Yersinia spp. and Proteus spp. were only found in the GBH-treated group. The prevalence of Klebsiella spp. and Pseudomonas spp. decreased in the intestinal microbiota of the GBH-CIP-treated group. To our knowledge, this is the first report on the alteration of cultivable enteric bacteria of autochthonous tadpoles due to two pollutants of emerging concern. Our results demonstrate that R. arenarum tadpoles can be used as non-conventional model organisms for environmental pollution monitoring. Our preliminary findings would contribute to understanding how the presence of GBH and CIP in freshwaters may represent a threat to wildlife and human health by causing enteric dysbiosis of part of the bacterial community.

Resumen Se recolectaron ejemplares de las especies de anfibios Leptodactylus melanonotus e Incilius marmoreus en varias localidades del estado de Colima, México, de julio a octubre de 2021. Durante estos muestreos, se descubrió una especie nueva de nemátodo del género Cosmocerca en el intestino de L. melanonotus; difiere del resto de las especies del género por la combinación de los siguientes caracteres: ausencia de alas laterales en machos, 5 plectanes, tamaño de las espículas y tamaño y forma del gubernáculo. Cosmocerca colimense n. sp. es la 39ava especie asignada a este género en el mundo y la segunda descrita en México. Se recolectaron 6 especies de helmintos en este estudio: Rauschiella poncedeleoni, Cosmocerca colimense n. sp., Oswaldocruzia subauricularis y Rhabdias sp. de L. melanonotus; Aplectana incerta y Oswaldocruzia pipiens de I. marmoreus.

Abstract Specimens of the amphibian species Leptodactylus melanonotus and Incilius marmoreus were collected in several localities in Colima State, Mexico, from July to October 2021. An undescribed species of nematode of the genus Cosmocerca was found in the intestine of L. melanonotus. The new species differs from every other species assigned to this genus by the combination of the following characters: absence of lateral alae in males, 5 plectanes, spicules size, and gubernaculum size and shape. This is the 39th species included in the genus worldwide and it is the second described in Mexico. Six helminth species were collected during this study: Rauschiella poncedeleoni, Cosmocerca colimense n. sp., Oswaldocruzia subauricularis, and Rhabdias sp. of L. melanonotus; Aplectana incerta and Oswaldocruzia pipiens of I. marmoreus.

Abstract Plinthite (Gr. Plinthos, brick) is a residual soil that occupies 60 million hectares on the planet. The Province of Misiones (Argentina) is the border zone of South America where this soil appears, locally called in its cemented state or petroplinthite as itácurú (stone toad in the Guarani language). Four centuries ago, it was used in the form of blocks cut from nearby deposits for the construction of the Jesuit reductions since 1601 in Loreto. Since then, there is a time jump until it is used in the construction of Coastal Route No. 2. In view of its potential and in the absence of systematic studies, this report aims to promote this mining resource for the restoration of reductions, constructions allegorical and road use. To this end, prospecting has been carried out in search of new deposits and others previously exploited that have been detected and evaluated; some used by the Jesuits. The location, size and approximate power of each of the explored deposits are presented, as well as the geotechnical values. The experimental results of the physical-mechanical properties and the effects on the properties of the different drying/wetting cycles carried out are presented and analyzed.

Resumen La plintita (Gr. Plinthos, ladrillo) es un suelo residual que ocupa 60 millones de has en el planeta. La Provincia de Misiones (Argentina) es la zona límite de América del Sur donde aparece este suelo, denominado localmente en su estado cementado o petroplintita como itácurú (piedra sapo en idioma guaraní). Cuatro siglos atrás fue utilizada en forma de bloques cortados de los yacimientos cercanospara la construcción de las reducciones jesuíticas desde 1601 en Loreto. Desde entonces existe un salto temporal hasta que se utiliza en la construcción de la Ruta Costera N° 2. En vista de su potencial y ante la falta de estudios sistemáticos el presente reporte tiene por objeto promover este recurso minero para la restauración de reducciones, construcciones alegóricas y uso vial. Para ello se ha realizado una prospección en busca de yacimientos nuevos y otrospreviamente explotados que han sido detectados y evaluados; algunos utilizados por los jesuitas. Se presentan la ubicación, tamaño y potencia aproximada de cada uno de los yacimientos explorados, así como los valores geotécnicos. Se presentan y analizan los resultados experimentales de las propiedades físico-mecánicas y los efectos en las propiedades de los diferentes ciclos de secado/humedecido realizados.

Resumen La garza ganadera (Bubulcus ibis) es un ave nativa de África que tiene la habilidad para adaptase a diferentes hábitats, características medioambientales y fuentes de alimento disponibles. Colectamos un total de 2,400 muestras de excremento de garza ganadera en cuatro colonias de descanso durante los meses de enero a marzo del 2020, en la región de Tulancingo de Bravo, Hidalgo México; con el objetivo de identificar los elementos que componen la dieta de la Garza ganadera. Las muestras de excremento fueron conservadas en alcohol al 70%, posteriormente fueron analizados con un microscopio estereoscópico. Identificamos un total de 1,677 elementos de 16 entidades taxonómicas, que se agruparon en cuatro categorías. Los artrópodos fueron el componente principal en las muestras (51.8%), principalmente insectos de la familia de los Ortópteros y Coleópteros. Otros componentes en las muestras fueron elementos vegetales (26.6%), restos de animales (13.9%), y plásticos u otros materiales no biológicos (7.7%). Adicionalmente, registramos por primera vez al Sapo de Puntos Rojos (Anaxyrus punctatus) como posible componente en la dieta de la garza ganadera. Esto coincide con otros estudios en donde La predominancia de los insectos, en particular Ortópteros y Coleópteros, en la dieta de la garza ganadera en nuestro estudio refleja la extensión de actividades agrícolas en la región. Nuestro estudio es el primer reporte sobre la dieta de la garza ganadera en una región agrícola de Hidalgo, México, y corresponde con otros estudios donde variaciones en la dieta dependen de la región, hábitat, clima y nivel de contaminación ambiental.

Abstract The Cattle Egret (Bubulcus ibis) is an avian species native to Africa that has the ability to adapt to different habitats, environmental characteristics, and available food sources. We collected a total of 2,400 Cattle Egret excreta from four resting colonies during the months of January to March 2020, in the region of Tulancingo de Bravo, Hidalgo, Mexico; in order to identify the elements that make up the diet of the Cattle Egret. Samples were placed in 70% alcohol, and later analysed with a stereoscopic microscope. We identified a total of 1,677 items from 16 taxonomic entities that could be grouped in four categories. Arthropods were the main component in samples (51.8%), particularly insects of the order Orthoptera and Coleoptera. Other components in samples were plant material (26.6%), animal remains (13.9%), and plastic or other non-biological material (7.7%). We also report the first record of the Red-Spotted Toad (Anaxyrus punctatus) as a possible component in the diet of the Cattle Egret. The predominance of insects, particularly Orthoptera and Coleoptera, in the Cattle Egret diet in our study reflects the extent of agricultural activities in the region. Our study provides the first report on the diet of the Cattle Egret in an agricultural area or Hidalgo, Mexico, and corresponds with other studies, where variations in diet depend on the region, habitat, climate, and extent of environmental contamination.

Abstract Host-parasite interactions can be harmful or harmless depending on the fitness and stress levels of the organisms. Interactions between the endocrine system, the immune system and energy expenditure are critical in the maintenance of homeostasis during stressful periods in vertebrates. We examined whether lungworm loads (Rhabdias spp.) of male cane toad (Rhinella marina) sampled during the wet season from three different populations, are associated with hormone levels, immune competence, and metabolic status. We found evidence of direct and strong associations between parasite burdens and variables related to hormonal levels, metabolic status and immune competence. We also found that interrelationships among independent variables can change the strength of the association with lungworm loads. These findings suggest that high levels of corticosterone affect immune competence against parasites, both directly and by inducing changes in the metabolic status of the animals. Additionally, high testosterone levels during the reproductive season, influenced variables related to metabolic status, which will also lead to higher parasite loads. Overall, we conclude that the endocrine system and metabolic status in male cane toads are critical to the immune competence against parasites during the reproductive season.

A tsunami of development projects is sweeping across the planet. This includes another 25 million kilometres of new paved roads by 2050 - enough to encircle the globe more than 600 times. Approximately 90% of these new roads will be built in low- and middle-income countries that are likely to have high biodiversity. This paper focuses on the environmental impact of 1.2 km of road planned to be built through endangered western leopard toad habitat and breeding ponds and extending into a greater wetland system in Cape Town. This paper reports a case study of the experiences of two female community environmental activists (the authors) throughout the public participation process and environmental impact assessment for this road. The results show the contesting of power in public participatory spaces as a form of trans-species accompaniment, and the generation of emotive knowledge (including distress and a sense of betrayal). The paper contributes to the existing knowledge of the execution of trans-species accompaniment in the context of public participation processes to seek ecojustice.

Abstract Xingnaojing (XNJ) injection was used to treat pneumonia and stroke in clinic in China, but with poor patient compliance. Xingnaojing nanoemulsion for intranasal delivery was developed to improve it. This article tried to evaluate the mucosal irritation of Xingnaojing nanoemulsion and investigate cellular uptake mechanism of its encapsulated lipophilic drugs. The toad palate model and rat nasal mucosa model were used to study the nasal ciliotoxicity and nasal mucosal irritation of nanoemulsion to evaluate its safety intranasally. The cellular uptake mechanism was studied by Calu-3 cell model. Coumarin 6 was encapsulated in nanoemulsion and the endocytic pathways were studied by cellular uptake experiments after being treated with different inhibitors. In toad palate model, the cilia movement of Xingnaojing nanoemulsion group last for 467.40 ± 39.02 min, which was obviously longer than deoxycholate group (90.60 ± 15.40 min). Studies on rats showed that the damage caused by nanemulsion is capable of being recovered. Nanoemulsion uptake was reduced obviously when cells were treated with wortmannin, and it also decreased about 13% when the temperature reduced from 37ºC to 4ºC. Mucosal irritation caused by nanoemulsion is low and the damage is recoverable. The cellular uptake of Xingnaojing nanoemulsion is energy-dependent, and macropinocytosis was the most important pathway for cellular uptake.

RESUMEN. Introducción: Existe poca información ecológica sobre el tejón o grisón mayor, Galictis vittata, incluida su distribución geográfica, dieta y hábitat. Objetivo: Informar el primer registro de este tejón capturando un sapo gigante. Métodos: Examinamos imágenes de cámaras-trampa de enero de 2019 a mayo de 2020. Resultados: Obtuvimos una foto de un tejón con el sapo en su hocico, en una finca de palma aceitera junto a un bosque en regeneración en Golfo Dulce, Costa Rica, y supusimos que la depredación fue exitosa. Conclusiones: Este registro representa el primer evento de depredación de R. horribilis por G. vittata, así como el primer registro de este tejón en una finca de palma aceitera en Costa Rica.

ABSTRACT. ''Predation of a giant toad (Rhinella horribilis) (Anura: Bufonidae) by the greater grison (Galictis vittata) (Carnivora: Mustelidae)”. Introduction: There is little ecological information on the grison, Galictis vittata, including its geographic distribution, diet and habitat. Objective: To report the first record of this grison eating a giant toad. Methods: We examined camera trap images from January 2019 to May 2020. Results: We obtained a photo of a grison with a giant toad in its mouth, from an oil palm plantation next to a regenerating forest in Golfo Dulce, Costa Rica, and assumed a successful act of predation. Conclusions: This record represents the first predation event of R. horribilis by G. vittata, as well as the first record of a grison in an oil palm plantation in Costa Rica.

This study investigated the chemical composition, immunomodulatory and antioxidant activities, and histopathological analysis of mice tissues treated with methanolic extract from R. marina poison. Marinobufagin, telecinobufagin and bufalin were identified in the chemical profile. The biochemical results demonstrated an effect between doses in the period of 7 days, an immunomodulatory effect was observed regarding the production capacity of interleukin (IL)-12p70 and tumor necrosis factor (TNF)-α at 7 and 30 days, respectively. The lower dose suggests better bioactivity to the treated animal than the higher dose. Histopathological analyses of the lung, heart, kidney and liver showed tissue damage in all organs, mainly in the lung, and were proportional to the dose and the treatment period. We observed that the treatment modulated cytokine production, and therefore this effect may be related to the tissue damage observed. This study demonstrates a positive effect in the antioxidant and immune system, indicating that the molecules found in the extract have biotechnological potential.

Resumen Introducción: Rhinella schneideri está ampliamente distribuida en Suramérica y su veneno es caracterizado por inducir cardiotoxicidad y neurotoxicidad. Objetivo: En este trabajo, investigamos estrategias farmacológicas para atenuar la neurotoxicidad periférica inducida por el veneno de R. schneideri en preparaciones neuromusculares de aves. Métodos: Los experimentos fueron realizados usando preparaciones de biventer cervicis de pollos sometidas a estimulación de campo para el registro de las contracciones musculares o expuestas a la acetilcolina y al cloruro de potasio para la respuesta contractural. Resultados: El veneno (10 µg/ml) provocó un bloqueo neuromuscular completo en las preparaciones después de aproximadamente 70 min de incubación (tiempos para 50 y 90 % de bloqueo: 15 ± 3 min y 40 ± 2 min, respectivamente; P < 0.05, N = 5); las contracturas en respuesta a la acetilcolina y el KCl exógenos no fueron afectadas por el veneno, indicando que no hay una interacción especifica con receptores postsinápticos o miotoxicidad respectivamente. El bloqueo neuromuscular causado por el veneno (10 µg/ml) no fue prevenido por la heparina (5 y 150 UI/ml) bajo condiciones pre y post-tratamiento. La incubación a bajas temperaturas (23-25 ºC) abolió el bloqueo neuromuscular; después de aumentar la temperatura a 37 ºC, el bloqueo neuromuscular total fue levemente más lento que el visto en preparaciones directamente incubadas a 37 ºC (tiempos para 50 y 90 % de bloqueo: 23 ± 2 min y 60 ± 2.5 min, respectivamente; P < 0.05, N= 4). Neostigmina (3.3 µM) no revirtió el bloqueo neuromuscular, mientras que 3.4-diaminopiridina (91.6 µM) produjo una reversión parcial y sostenida de las respuestas neuromusculares (29 ± 7.8 % de la reversión máxima alcanzada en aproximadamente 40 min de incubación; P < 0.05, N = 4). Conclusiones: El veneno de R. schneideri indujo neurotoxicidad periférica potente in vitro, el cual puede ser revertido por 3.4-diaminopiridina.

Abstract Introduction: Rhinella schneideri is a toad widely distributed in South America and its poison is characterized by inducing cardiotoxicity and neurotoxicity. Objective: In this work, we investigated pharmacological strategies to attenuate the peripheral neurotoxicity induced by R. schneideri poison in avian neuromuscular preparation. Methods: The experiments were carried out using isolated chick biventer cervicis preparation subjected to field stimulation for muscle twitches recordings or exposed to acetylcholine and potassium chloride for contracture responses. Results: Poison (10 μg/ml) produced complete neuromuscular blockade in chick biventer cervicis preparation within approximately 70 min incubation (times for 50 and 90 % blockade: 15 ± 3 min and 40 ± 2 min, respectively; P < 0.05, N= 5); contracture responses to exogenous acetylcholine and KCl were unaffected by poison indicating no specificity with postsynaptic receptors or myotoxicity, respectively. Poison (10 μg/ml)-induced neuromuscular blockade was not prevented by heparin (5 and 150 IU/ml) under pre- or post-treatment conditions. Incubation at low temperature (23-25 °C) abolished the neuromuscular blockade; after raising the temperature to 37 °C, the complete neuromuscular blockade was slightly slower than that seen in preparations directly incubated at 37 °C (times for 50 and 90 % blockade: 23 ± 2 min and 60 ± 2.5 min, respectively; P < 0.05, N= 4). Neostigmine (3.3 μM) did not reverse the neuromuscular blockade in BC preparation whereas 3,4-diaminopyridine (91.6 μM) produced a partial and sustained reversal of the twitch responses (29 ± 7.8 % of maximal reversal reached in approximately 40 min incubation; P < 0.05, N= 4). Conclusions: R. schneideri poison induces potent peripheral neurotoxicity in vitro which can be partially reversible by 3,4-diaminopyridine.

RESUMEN Atelopus balios es un sapo endémico de Ecuador, con categoría amenazada debido al cambio de cobertura vegetal y la polución ambiental. Se desconoce sobre sus poblaciones e interacciones ecológicas. El presente estudio da a conocer una línea base sobre el tamaño poblacional y algunos aspectos ecológicos. Durante octubre y noviembre de 2017, se estimó el tamaño poblacional de A. balios en una localidad de Naranjal, piedemonte de la cordillera occidental, Ecuador. Se realizó dos transectos lineales de 1000 metros en dos ríos de la región, donde se hizo dos muestreos diurnos de captura-recaptura por medio de encuentros visuales, y se utilizó la fotoidentificación para estimar el tamaño de la población. También se evaluó su tamaño corporal, estructura poblacional, uso de sustrato, su actividad, y su distribución vertical y horizontal. Obtuvimos 32 registros que corresponden a 29 individuos únicos (T1= 3 ind y T2= 26 ind). La proporción de machos/hembras fue de 8.6:1. En T1 no se pudo aplicar el estimador de población. En T2 se estimó 52.25±EE18.64 individuos. El 59.37% utiliza el sustrato de hoja, el 75% presentó actividad desplazándose al momento de la captura, su distribución vertical es entre 20 y 250 cm de alto, su distribución horizontal fue entre 20 y 1000 cm. Se desconoce sobre la presencia de quitridio, pero se considera importante diagnosticar su presencia y prevalencia. Aunque la abundancia en ambos transectos varía, se considera que las poblaciones son estables y su fluctuación es normal. Por lo que es importante realizar monitoreos.

ABSTRACT Atelopus balios is a toad endemic to Ecuador, with a threatened category due to change in plant cover and environmental pollution. It is unknown about their populations and ecological interactions. This study discloses a baseline on population size and some ecological aspects. During October and November 2017, the population size of A. balios was estimated in a locality of Naranjal, foothills of the western mountain range, Ecuador. Two linear transects of 1000 meters were carried out in two rivers of the region, where two daytime sampling of capture-recapture was performed through visual encounter surveys, and photoidentification was used to estimate population size. Also there was evaluated its corporal size, population structure, used substrate, its activity, and its vertical and horizontal distribution. We obtained 32 records that correspond to 29 only individuals (T1 = 3 ind and T2 = 26 ind). The male/female ratio was 8.6:1. In T1, the population estimator could not be applied. In T2, 52.25±EE18.64 individuals were estimated. We found that 59.37% used leaf substrate, 75% had activity moving at the time of capture, its vertical distribution is between 20 and 250 cm high, its horizontal distribution was between 20 and 1000 cm. It is unknown about the presence of quitridium, but it is considered important to diagnose its presence and prevalence. Although the abundance in both transects varies, populations are considered stable and their fluctuation is normal. So it's important to perform monitoring.

Rhinella jimi toads (Stevaux, 2002) belong to the Bufonidae family, are endemic in the Brazilian Northeast and are commonly found during rainy periods. In general, amphibians of this family have in their poisons different metabolites that show a diversity of pharmacological activities. The isolation and identification of these compounds are of great importance, and techniques such as high-performance liquid chromatography coupled to mass spectrometry are widely used for the discovery of novel and known compounds in these poisons. For R. jimi poison, the ethyl acetate and methanolic extracts were obtained and thirty compounds were identified by combining ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS) with direct infusion atmospheric pressure chemical ionization mass spectrometry (DI-APCI-MS/MS) and direct infusion electrospray mass spectrometry (DI-ESI-MS/MS) for each extract, respectively. Marinobufagin (2) and marinobufotoxin (19) were the majorities of each extract, respectively. In addition, other bufadienolides mainly present in the ethyl acetate extract, such other bufotoxins, alkaloids and arginine diacid derivatives were identified in the methanol extract. In a cytotoxic assay by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the extracts and compound 2 demonstrated half-maximal inhibitory concentration (IC50) values better than the positive control doxorubicin, evidencing excellent cytotoxic. This is the most complete study of the chemical composition of R. jimi toad poison and its respective cytotoxic activity, promoting the enrichment of knowledge about this family and species.