Resumen En Colombia, los anfibios se posicionan como uno de los grupos vertebrados con mayor riqueza taxonómica, y una alta representatividad de especies endémicas. En los últimos años, las colecciones regionales han contribuido a llenar vacíos de información sobre la biogeografía, la variación intra e interespecífica y la sistemática de los anfibios del país. En este trabajo presentamos la información de 1533 registros depositados en la Colección de Anfibios del Museo de Historia Natural de la Universidad de Caldas, los cuales representan 143 especies distribuidas en 49 géneros y 19 familias. La mayoría de los especímenes (n = 1194) proceden del departamento de Caldas, sin embargo, se cuenta con registros (n = 339) de otros 16 departamentos del país. El orden más representado es Anura (n = 1487 registros), seguido por Caudata (n = 27 registros) y Gymnophiona (n = 19 registros). La colección alberga 152 especímenes que han sido referenciados en 13 publicaciones nacionales y extranjeras.

Abstract In Colombia, amphibians are a vertebrate group with a high taxonomic richness, and an elevated representativity of species with restricted distributions. In recent years, regional collections have assisted to fill information gaps on the biogeography, intra- and interspecific variation, and systematics of the amphibians of the country. In this work we present the information of 1533 records deposited in the Amphibian Collection of the Museo de Historia Natural of the Universidad de Caldas, represented by 143 species, belonging to 49 genera and 19 families. Most of the records (n = 1194) come from the Department of Caldas, but there are records for 16 additional departments. The most representative order is Anura (n = 1487 records) followed by Caudata (n = 27 records), and Gymnophiona (n = 19 records). The collection houses 152 specimens that have been referenced in 13 national and foreign publications.

Abstract The Atlantic Forest is one of the world’s biodiversity hotspots. The Pico do Marumbi State Park is home to an evergreen ombrophilous forest with areas of transition to the Araucaria moist forest. In spite of the high diversity of life forms in the area, there are few studies of understory herbaceous plants. The present study reports the rediscovery for Brazil and the first record for Paraná state of an extremely rare species of Thismiaceae, Thismia caudata. The only record so far has been for the Rio de Janeiro state. In February 2021, T. caudata was discovered with fruit and flower. We also present other records of achlorophyllous herbaceous species that were occasionally found near the rediscovered Thismiaceae. In total, eight species belonging to five families are reported with descriptions of the morphology and natural environment, as well as phenological aspects. These are T. caudata, T. cordata, and T. panamensis (Thismiaceae); Langsdorffia hypogaea (Balanophoraceae); Voyria aphylla (Gentianaceae); Apteria aphylla and Gymnosiphon tenellus (Burmanniaceae); Triuris hyalina (Triuridaceae). In addition, we present the very first photographs of T. caudata.

Resumo A floresta Atlântica costeira é um dos hotspot de biodiversidade no nível mundial. O Parque estadual Pico do Marumbi apresenta floresta ombrófila sempre verde com áreas de transição com a floresta com araucária. A alta diversidade de formas de vida na área apresenta poucos estudos das plantas herbáceas do sub-bosque. Este estudo reporta o redescobrimento para o Brasil e o primeiro registro para o estado do Paraná de uma espécie de Thismiaceae extremamente rara, Thismia caudata. O único registro até agora foi para o estado de Rio de Janeiro. Em fevereiro de 2021 T. caudata foi descoberta com fruto e flor. Também apresentamos outras espécies herbáceas aclorofiladas registradas e as vezes, acompanhantes da Thismiaceae redescoberta. No total oito espécies pertencentes a cinco famílias são reportadas com descrição da morfologia e do ambiente natural como de aspectos fenológicos. Essas foram: T.caudata, T. cordata e T. panamensis (Thismiaceae); Langsdorffia hypogaea (Balanophoraceae); Voyria aphylla (Gentianaceae); Apteria aphylla e Gymnosiphon tenellus (Burmanniaceae) e Triuris hyalina (Triuridaceae). Apresentamos as primeiríssimas fotografias de T. caudata.

Resumen En la familia de las Lauraceae el género Ocotea presenta especies como fuentes de madera para la construcción, la ebanistería, el biocombustible, la desinfección, la cosmética y para el tratamiento de diversas enfermedades. Ocotea caudata tiene pocos estudios fitoquímicos y farmacognósticos: este trabajo es el primero que estudia los frutos de esta especie. Los frutos de O. caudata (Nees) Mez de Colombia fueron investigados por su contenido de aceite. La extracción con heptano del aceite de los frutos de O. caudata arrojó un 54.9 % de lípidos totales y se determinó la composición de ácidos grasos. El análisis GC-FID (Gas Chromatography Flame Ionization Detector) del aceite indicó que el ácido láurico es el ácido graso más abundante en el aceite (51.7 %, C12:0). Además del ácido láurico, se encontró ácido oleico (23.6 %, C18:1) y ácido palmítico (16.6 %, C16:0). El ácido láurico se considera fuente de numerosos beneficios para la salud. Por lo tanto, el alto contenido de ácido láurico en O. caudata ofrece la posibilidad de utilizar este aceite como componente importante en usos nutricionales y de salud. O. caudata puede considerarse una especie que acumula ácidos grasos saturados de cadena media (C12) y ácidos grasos insaturados de cadena larga (C18).

Abstract The genus Ocotea of the Lauraceae family has species whose wood is employed in construction and for other purposes including as biofuel, for disinfection, cosmetics, and in the treatment of various diseases. Studies regarding Ocotea caudata’s phytochemical and pharmacognostic uses are scarce, thus, this work is the first to study its fruits. O. caudata (Nees) Mez fruits from Colombia were investigated for their oil content. Heptane extraction from O. caudata fruit oil yielded 54.9 % of total lipids, where the fatty acid composition was determined. The oil analysis by gas chromatography with flame ionization detection (GC-FID) demonstrated that lauric acid was the most abundant fatty acid (51.7 %, C12:0). In addition to lauric acid, oleic acid (23.6 %, C18:1) and palmitic acid (16.6 %, C16:0) were found. The fatty acid composition was confirmed by gas chromatography-mass spectrometry (GC-MS). O. caudata can be considered as a species that accumulates medium-chain saturated fatty acids (C12) and long-chain unsaturated fatty acids (C18). In conclusion, many of its health benefits may be due to its high content of lauric acid. Therefore, this oil is highly regarded for its nutritional and health properties.

Resumen: Antecedentes y Objetivos: En algunos países, los habitantes de las comunidades rurales complementan su dieta con frutos obtenidos de plantas silvestres, los cuales generalmente carecen de información nutricional y fitoquímica, como ocurre con los frutos de las especies endémicas en México del género Jarilla (Caricaceae). Por lo tanto, el objetivo de esta investigación fue estudiar la composición nutricional de frutos de Jarilla caudata en términos de su análisis químico proximal, contenido de minerales y aminoácidos, así como determinar la presencia de metabolitos secundarios, contenido total de compuestos fenólicos y flavonoides. Métodos: Los frutos se colectaron en el municipio Teocuitatlán de Corona, Jalisco, en julio de 2018 y 2019. Para determinar la composición químico proximal se siguieron los métodos oficiales de análisis de AOAC. El contenido de minerales se determinó por espectrofotometría de absorción atómica y los aminoácidos por cromatografía de líquidos de alta resolución (HPLC). Para el análisis de metabolitos secundarios se utilizaron diversos reactivos, y el contenido de compuestos fenólicos y flavonoides totales se cuantificó por espectrofotometría. Resultados clave: En comparación con otros frutos silvestres de la familia Caricaceae, los resultados indicaron que los frutos de J. caudata representan una buena fuente de carbohidratos y proteínas (35.7 y 18.9 g/100 g respectivamente), así como de algunos minerales (K, P y Ca). Se observó un pobre perfil y contenido de aminoácidos. El promedio de compuestos fenólicos totales fue de 387.5 mg GAE/100 mg, mientras que el de flavonoides totales fue de 56.5 mg QE/100 mg. No se detectaron compuestos considerados tóxicos o antinutricionales como alcaloides y glucósidos cianogénicos. Conclusiones: Durante el verano, los frutos de J. caudata pueden tener un papel importante como complemento alimenticio para los habitantes de la región de Teocuitatlán de Corona, aportando diferentes nutrientes, particularmente carbohidratos y proteínas, así como otros compuestos con efectos favorables para la salud como los polifenoles.

Abstract Background and Aims: In some countries, the inhabitants of rural communities supplement their diet with fruits obtained from wild plants, which usually lack nutritional and phytochemical information, as occurs with the fruits of the Mexican endemic species of the genus Jarilla (Caricaceae). Therefore, the aim of this research was to study the nutritional composition of Jarilla caudata fruits in terms of their proximal chemical analysis, mineral content and amino acid composition, and determine the presence of secondary metabolites, the total content of phenolic compounds and flavonoids. Methods: The fruits were collected in the municipality Teocuitatlán de Corona, Jalisco, in July 2018 and 2019. The proximal chemical composition was analyzed using the official methods of analysis (AOAC), the mineral content was determined by means of atomic absorption spectrophotometry, while the amino acids were analyzed by high performance liquid chromatography (HPLC). Various reagents were used for the preliminary determination of secondary metabolites. The content in phenolic compounds and total flavonoids was quantified by spectrophotometry. Key results: In comparison with other fruits of the Caricaceae family, the results indicated that the fruits of J. caudata represent a good source of carbohydrates and proteins (35.7 and 18.9 g/100 g, respectively), as well as some minerals (K, P and Ca). A poor amino acid profile and content was found. The average content of total phenolic compounds was 387.5 mg GAE/100 mg, while that of flavonoids was 56.5 mg QE/100 mg. Compounds considered toxic or antinutritional, such as alkaloids and cyanogenic glycosides, were not detected. Conclusions: During summer the fruits of J. caudata can play an important role as a food supplement for the inhabitants of the region of Teocuitatlán de Corona, providing different nutrients, particularly carbohydrates and proteins, as well as other compounds with favorable health effects, such as polyphenols.

Abstract Ecosystem engineering species create, modify, and/or maintain the characteristics of the environment. The polychaete Phragmatopoma caudata builds large sand reefs in the intertidal region of the Brazilian coast with high structural complexity, favoring the increase of diversity and interactions among the species associated. However, there are no studies concerning the association of polychaetes with crustacean macrofauna in the northeastern Brazil ecoregion, leaving an information gap on baseline biodiversity. Our aim was to analyze the effect of P. caudata colonies (PC) on the local diversity of macrocrustaceans compared to the rocky shore (RS) microhabitat. Monthly collections were carried out in low tide from September 2015 to August 2016 on 10 × 10 m quadrants for fauna and environmental variables (temperature and salinity) samples. In each microhabitat, the capture effort was two hours by two researchers. We collected 3,390 individuals, 60% associated with the colonies of PC and 40% with the RS. The PC obtained higher Shannon diversity, Pielou evenness and species richness coupled with milder water temperature and salinity conditions (minor air exposure during tide), compared to the RS that obtained greater species dominance and more extreme abiotic conditions (major air exposure). The Porcellanidae family stood out because all its species were highly abundant and had high occurrence in the colonies. The tropical Brazil porcelain crab Pachycheles greeleyi was dominant in both microhabitats (major dominance in PC). The structural complexity in the reefs of PC promoted higher availability of niches for the species, as more shelter for the resident species and refugium for temporary species with preference for more complex microhabitats. Conservation managers should prioritize the health of these colonies and subsequent species that constitute important ecosystemic and fishery resources.

RESUMEN Los ajolotes de arroyos de alta montaña (Ambystoma), forman parte de especies vulnerables debido a la naturaleza de su distribución, la cual se restringe a pequeños arroyos permanentes en las montañas de la Faja Volcánica Transmexicana; estas especies, además, se conforman por poblaciones pequeñas y aisladas, lo cual incrementa su vulnerabilidad. En este trabajo se analizan las amenazas potenciales para Ambystoma rivulare, A. altamirani y A. leorae, y con base en los criterios propuestos por la SEMARNAT y el Puntaje de Vulnerabilidad Ambiental desarrollado por Wilson y McCranie (2003), se argumenta que el estado de conservación de estas especies puede cambiarse a un nivel de mayor protección.

ABSTRACT High mountain stream’s mole salamanders (Ambystoma) are vulnerable species owing to their restricted distribution, which is limited to little streams located at high mountains in the Trans-Mexican Volcanic Belt. Besides, those species are formed by small and isolated populations increasing their vulnerability. Potential threats to Ambystoma rivulare, A. altamirani, and A. leorae, were reviewed, based on SEMARNAT criteria, and the Environmental Vulnerability Score (EVS) proposed by Wilson and McCranie (2003). If conservation status should be changed to a higher level of protection is discussed.

Resumen A pesar de que más del 10 % de la riqueza global de anfibios se encuentra en Colombia, cerca del 16 % de estas especies es actualmente clasificada con Datos Deficientes según la IUCN. Estas estimaciones sugieren que los datos disponibles para esta gran porción de anfibios que habitan en Colombia, son insuficientes para evaluar su riesgo de extinción. En este documento nosotros (1) revisamos la información disponible sobre la distribución de los anfibios colombianos con Datos Deficientes (ó DD), (2) analizamos su distribución geográfica, e (3) hipotetizamos sobre la relación entre el impacto antropogénico y su estado de conservación. Para esto, compilamos los registros geográficos para las especies de anfibios DD usando referencias primarias. Los registros geográficos fueron obtenidos principalmente a partir de descripciones taxonómicas y búsquedas no sistemáticas. Para estimar la distribución geográfica e inferir la distribución potencial de cada especie usamos letsR y MaxEnt, respectivamente. Cuantificamos la huella humana para cada especie y evaluamos la relación entre la distribución espacial y el cambio antropogénico entre poblaciones. Los análisis fueron basados en 128 de las 129 especies de anfibios que se encuentran en Colombia y actualmente son clasificadas como DD. Encontramos que la mayoría de estas especies fueron descritas recientemente, y presentan una distribución geográfica reducida. Una gran proporción de estas especies de anfibios DD habitan los Andes colombianos, y sus poblaciones han sido fuertemente afectadas por las actividades humanas. Este agrupamiento geográfico sugiere que muchas de estas especies enfrentan similares presiones ambientales y antropogénicas que contribuyen a su rareza. Sugerimos además que el estado de conservación para muchas de las especies de anfibios DD aquí analizados podría ser reevaluado para considerar las amenazas que enfrentan.

Abstract Whereas more than 10 % of global amphibian richness is known to occur in Colombia, almost 16 % of these species are currently classified as Data Deficient according to the IUCN. These estimates suggest that the available data for a large portion of amphibians occurring in Colombia is insufficient to assess extinction risk. Here we aim to (1) review the available information on the distribution of the Colombian Data Deficient (DD hereafter) amphibians, (2) analyze their geographic distribution, and (3) evaluate the relationship between anthropogenic impact and their current conservation status. For this, we first compiled geographical records for the DD amphibian species using primary sources. Geographical records were obtained mainly from taxonomic descriptions and non-systematic surveys. We then estimated the geographical range and inferred the potential distribution for each species using letsR and MaxEnt, respectively. We quantified the human footprint for each species and tested the relationship between spatial distribution and anthropogenic change across populations. Analyses are here based on 128 of the 129 DD amphibian species that occur in Colombia. We found that most of these species were recently described and have small geographic ranges. A large proportion of these DD amphibians inhabit the Colombian Andes, and their populations have been strongly affected by human activities. Overall, the spatial clustering suggests that many of these species have faced similar environmental and anthropogenic pressures that have contributed to their rareness. We also suggest that the conservation status for several of the analyzed DD amphibians should be changed to account for the threats they face. Rev. Biol. Trop. 66(3): 1272-1281. Epub 2018 September 01.

RESUMO Este trabalho descreve e ilustra 50 táxons do filo Euglenophyta amostrados em quatro lagoas da sub-região da Nhecolândia, no Pantanal Sul-Matogrossense. Do total de táxons identificados, 33 foram em nível infra-específico, com 15 variedades típicas e 18 variedades não-típicas. Dentre as espécies identificadas, uma nova espécie, Trachelomonas globularis (Awer.) Lemm. var. gigas Drezepolski, foi registrada pela primeira vez no Brasil e duas espécies citadas pela segunda vez: Lepocinclis americana Conforti e Trachelomonas pyramidata Couté et Thérézien. O gênero com maior número de espécies foi Trachelomonas, seguido de Lepocinclis e Phacus. Os táxons com maior distribuição ecológica foram Euglena caudata Hübner var. caudata, Lepocinclis acus (O.F. Müller) Marin & Melkonian, L. spyrogiroides Marin & Melkonian, T. armata (Ehr.) Stein. var. steinii Lemm.,T. megalacantha Cunha var. crenulatocollis Bourr. & Manguin, T. superba Sw. var. superba e T. volvocinopsis Sw. var. volvocinopsis.

ABSTRACT This study describes and illustrates 50 taxa of the phylum Euglenophyta sampled in four lakes from the Nhecolândia subregion of the Brazilian Pantanal. Of the total taxa identified, 33 were at infra-specific level, with 15 typical varieties and 18 non-typical varieties. Among identified species, Trachelomonas globularis (Awer.) Lemm. var. gigas Drezepolski was recorded for the first time in Brazil, and Lepocinclis americana Conf. and Trachelomonas pyramidata Couté et Thérézien were mentioned for the second time in Brazil. The most abundant genus was Trachelomonas, followed by Lepocinclis and Phacus. The most widespread taxa were Euglena caudata Hübner var. caudata, Lepocinclis acus (Müller) Marin & Melkonian, L. spyrogiroides Marin & Melkonian, T. armata (Ehr.) Stein. var. steinii Lemm., T. megalacantha Cunha var. crenulatocollis Bourr. & Manguin, T. superba Sw. var. superba and T. volvocinopsis Sw. var. volvocinopsis.

Resumen: La sirena menor (Siren intermedia) es registrada por primera vez en Tuxpan, por segunda vez en el estado de Veracruz y por tercera vez en México. Este hallazgo incrementa los puntos de distribución de la especie, previamente informada para Matamoros y Ciudad Victoria, Tamaulipas y Gutiérrez Zamora, Veracruz. Hasta donde se sabe, esta especie tiene una distribución disyunta en México.

Abstract: The Lesser siren (Siren intermedia) is recorded for the first time in Tuxpan, for the second time in the state of Veracruz, and for the third time in Mexico. This finding increases the points of distribution of this species, previously reported from Matamoros and Ciudad Victoria, Tamaulipas and Gutierrez Zamora, Veracruz. This species has so far, a disjunct distribution in Mexico.

Resumen: La familia extinta Albanerpetontidae es, a la fecha, la única familia incluida dentro de Allocaudata, y junto con Anura, Caudata y Gymnophiona conforma el clado Lissamphibia, el cual tiene un alcance temporal desde el Triásico temprano al reciente. Esta familia incluye un único género norteamericano, Albanerpeton , cuya distribución temporal se extendió desde el Cretácico Temprano (Aptiano/Albiano temprano) al Plioceno. Desde 2004 se han realizado expediciones paleontológicas en rocas de la formación El Gallo, de edad campaniana (Cretácico Tardío), en Baja California, México. Como resultado se han descubierto numerosos sitios con abundantes restos de microfósiles. En uno de ellos, denominado ROS51, fueron colectados fragmentos de un dentario y un premaxilar con dientes, identificados como pertenecientes a la Familia Albanerpetontidae. Los caracteres morfológicos que permitieron su identificación son: dientes robustos, pleurodontos no pedicelados que se encuentran muy cercanos entre sí. Estos materiales constituyen el primer registro para México siendo el más austral y el primero en la costa pacífica de Norte América.

Abstract: The extinct family Albanerpetontidae is the only family included within Allocaudata so far known to date. This family lies within the clade Lissamphibia along with Anura, Caudata and Gymnophiona, which spans from the Triassic period to the present. This family includes the single North American genus, Albanerpeton , which is recorded from the Early Cretaceous (Aptian/earliest Albian) to the Pliocene epochs. Since 2004, paleontological expeditions have been performed in the El Gallo formation (Campanian, Late Cretaceous) in Baja California, Mexico. The results of such field work have resulted in the discovery of several new sites yielding microvertebrates. In one of the ROS51 site, fragments belonging to the family Albanerpetontidae were recovered, which includes remains of a dentary and a premaxilla with teeth. The morphological characters that allow their identification as belonging to the family are: pleurodont and non-pedicelate closely spaced robust teeth, closely spaced. This represents the first record of this family in Mexico, and being the southernmost occurrence and the first one collected on the Pacific coast of North America.

RESUMO O trabalho objetivou o estudo taxonômico de microalgas do gêneroTrachelomonas (Euglenophyceae) na Área de Proteção Ambiental (APA) do rio Ibirapuitã, localizada na fronteira sudoeste do Estado do Rio Grande do Sul. Foram amostradas 10 estações de coleta em ambientes lóticos e lênticos, no período de 2011 a 2013. As 34 amostras resultantes de quatro coletas foram obtidas com rede de plâncton com abertura de malha de 30 µm, e conservadas com formol a 4%. São apresentados os nove táxons que são novos registros para o Estado do Rio Grande do Sul, encontrados em somente três estações de coleta das 10 amostradas. Dentre esses, distinguem-se ainda por serem citados pela primeira vez para o Brasil: Trachelomonas bernardii Wolosz. f. major Defl., T. caudata Defl. f. pseudocaudata (Defl.) Pop.,T. hirta Cunha var. hirta e T. torosa (Bal.) Tell & Conf.

ABSTRACT The aim of this study was the taxonomic analysis of microalgae from the genusTrachelomonas (Euglenophyceae) in the Environmental Protection Area (APA) of the Ibirapuitã River, located on the southwest border of Rio Grande do Sul State. We sampled 10 stations in lotic and lentic environments, between 2011 and 2013. The 34 samples, resulting from sampling, were collected with a plankton net (30 µm), and preserved with 4% formalin. Nine taxa are new records for Rio Grande do Sul State, found in only three of the 10 stations sampled. Among these, Trachelomonas bernardii Wolosz. f. major Defl., T. caudata Defl. f. pseudocaudata (Defl.) Pop., T. hirta Cunha var. hirta, and T. torosa (Bal.) Tell & Conf. are first reports for the country.

El establecimiento de áreas de pastoreo en ambientes húmedos tropicales es una de las causas de la reducción de las poblaciones de anfibios. Este trabajo evalúa las consecuencias del establecimiento de las áreas de pastoreo en las comunidades de anfibios en un área de la Sierra Madre Oriental por medio del análisis de diversidad alfa y beta. El muestreo se realizó en 28 localidades; 7 de bosque tropical perennifolio (TEF), 7 de bosque mesófilo de montaña (MCF) no alterado, 7 en áreas de pastoreo tropicales (TGA) y 7 en áreas de pastoreo de bosque mesófilo (CFGA), usando el método de muestreo directo. La diversidad de anfibios se reduce cuando las áreas de pastoreo se establecen en ambientes tropicales (TGA, 8 especies; 7.1 especies efectivas y TEF, 10 especies; 7.7 especies efectivas); en contraste, el CFGA presenta una mayor diversidad (11 especies; 9.3 especies efectivas) comparado con el MCF (8 especies; 3.9 especies efectivas). La composición más disímil se encontró entre las comunidades de los bosques conservados (MCF-TEF, 0.78 disimilitud de Jaccard). El establecimiento de áreas de pastoreo en los TEF influye con mayor intensidad en la reducción de las poblaciones de anfibios, en comparación con el MCF.

The establishment of grazing areas in humid tropical environments is one of the causes of amphibian population decline. This work evaluates the consequences of the establishment of grazing areas on amphibian communities in an area of the Sierra Madre Oriental using analyses of alpha and beta diversity. Sampling was conducted at 28 locations, 7 in tropical evergreen forest (TEF), 7 in mountain cloud forest (MCF), 7 in tropical grazing areas (TGA), and 7 in cloud forest grazing areas (CFGA) using the method of direct sampling. Amphibian diversity is reduced when the grazing areas are established in tropical environments (TGA, 8 species; 7.1 effective species and TEF, 10 species; 7.7 effective species); in contrast, the CFGA has a greater diversity (11 species; 9.3 effective species) compared with MCF (8 species; 3.9 effective species). The most dissimilar composition was found between the 2 communities of undisturbed forests (MCF-TEF; Jaccard dissimilarity 0.78). Establishment of grazing areas in TEF strongly influences the reduction of amphibian populations when compared with MCF.

Resumo A região da Volta Grande no Rio Xingu, localizada no estado do Pará, apresenta várias frentes de exploração que vão desde a criação animal até área de cultivo, resultando no desmatamento de fragmentos florestais. Atualmente a região está sendo impactada pela implantação da Usina Hidrelétrica de Belo Monte. A partir de dados obtidos através dos Programas de Monitoramento Ambiental realizados na área de influência da UHE Belo Monte, apresentamos uma listagem das espécies de anfíbios e répteis, com comentários sobre a distribuição espacial das assembleias. Foram catalogados 109 espécies de anfíbios (Anura, Caudata e Gymnophiona) e 150 de répteis (Squamata, Testudines e Crocodylia). Considerando as incertezas taxonômicas, a complexidade e a diversidade críptica de várias espécies, a riqueza regional ainda continua subestimada, assim como observado em outras regiões da Amazônia. Esforços direcionados ao aproveitamento científico e estudos que contemplem a taxonomia integrativa são necessários para elucidar as incertezas e aumentar o nível de conhecimento sobre a diversidade da região.

Abstract The region of Volta Grande do Xingu River, in the state of Pará, presents several kinds of land use ranging from extensive cattle farming to agroforestry, and deforestation. Currently, the Belo Monte Hydroelectric Power Plant affects the region. We present a checklist of amphibians and reptiles of the region and discuss information regarding the spatial distribution of the assemblies based on results of Environmental Programmes conducted in the area. We listed 109 amphibian (Anura, Caudata, and Gymnophiona) and 150 reptile (Squamata, Testudines, and Crocodylia) species. The regional species richness is still considered underestimated, considering the taxonomic uncertainty, complexity and cryptic diversity of various species, as observed in other regions of the Amazon biome. Efforts for scientific collection and studies related to integrative taxonomy are needed to elucidate uncertainties and increase levels of knowledge of the local diversity.

En Argentina, la única especie del género Chiroxiphia registrada hasta la fecha es el Bailarín Azul (Chiroxiphia caudata), presente en las provincias de Misiones y Corrientes. En este trabajo se reporta el primer registro para Argentina del Bailarín Yungueño (Chiroxiphia boliviana) en base a la captura de un individuo juvenil y grabaciones de cantos de cuatro individuos en la finca Pintascayo, departamento Iruya, provincia de Salta. Con este registro se extiende el rango de distribución de esta especie desde el departamento Chuquisaca en el sudeste de Bolivia aproximadamente 350 km hacia el sur.

Yungas Manakin (Chiroxiphia boliviana), a new species in Argentina.- Currently, the only species of the genus Chiroxiphia recorded for Argentina is the Blue Manakin (Chiroxiphia caudata) in Misiones and Corrientes provinces. In this study, the first record of Yungas Manakin (Chiroxiphia boliviana) in Argentina is reported based on a juvenile captured and the sound recordings of four individuals in Finca Pintascayo, Iruya Department, Salta Province. With this record the distributional range of this species is extended 350 km towards the South from Chuquisaca Department in south-eastern Bolivia.