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RESUMEN La Orinoquia andina en Colombia ha sido muy afectada por la intervención antrópica. Aunque se han realizado ejercicios de priorización de áreas importantes para la conservación que han incluido a los peces de agua dulce, estos sólo han tenido en cuenta variables como la riqueza, endemismos y estatus de amenaza, que resultan insuficientes para representar la variabilidad geográfica y los patrones de distribución de las especies. En este trabajo, se propone una priorización para la conservación de los peces en la Orinoquia andina a partir de tres enfoques: identificación de áreas de endemismo, riesgo y complementariedad. Los tres enfoques coinciden en la priorización de la subcuenca del río Ariari como la más importante para la conservación de los peces, seguida por la subcuenca del río Guamal, abarcando en conjunto el 72,35 % de la ictiofauna de la Orinoquia Andina. Aunque el 47,07 % del área de estudio pertenece a algún tipo de área protegida, solo el 0,97 % de los registros de peces provienen de áreas protegidas nacionales y el 14,8 % de áreas regionales, resaltando el bajo conocimiento de la diversidad de peces en estas áreas. Se exhorta a las autoridades ambientales, institutos de investigación y universidades, a realizar investigación básica en las áreas protegidas, que permitan conocer su riqueza y analizar su efectividad para conservar la ictiofauna. ABSTRACT The Andean Orinoco basin in Colombia has been strongly affected by the anthropic impact. Although prioritization efforts have been done in important areas for conservation that have included freshwater fish, they have only considered richness, endemism, and threat status which are insufficient to represent the geographical variability and the distribution patterns of species. In this work, prioritization for the conservation of fishes in the Andean Orinoco is proposed based on three approaches: identification of areas of endemism, risk, and complementarity. The three approaches coincide in the prioritization of the Ariari river sub-basin as the most important for fish conservation, followed by the Guamal River sub-basin, together encompassing 72.35 % of the Andean Orinoco ichthyofauna. Although 47.07% of the study area belongs to some type of protected area, only 0.97 % of the fish records come from national protected areas and 14.8 % from regional areas, highlighting the low knowledge of the freshwater fish diversity in these areas. Environmental authorities, research institutes, and universities are urged to carry out basic research in the protected areas that allow to know its richness and to analyze its effectiveness to conserve ichthyofauna.

Hoplias malabaricus is one of the most widespread freshwater fish in the Neotropics; all karyotyped populations exhibit diploid numbers ranging from 2n = 39 to 2n = 42, with variations that make up...

Since 2000, collaborative and multidisciplinary field inventories have helped quadruple park coverage in Peru’s richest region., Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require >3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering >9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth.

Interdisciplinary Research in Earth Sciences program [NNX14AD29G]; MacArthur Foundation under the Living Andean Rivers initiative [16-1607-151053-CSD]

The Neotropical region represents one of the greatest biodiversity hot spots on earth. Despite its unparalleled biodiversity, regional comparative phylogeographic studies are still scarce, with most focusing on model clades (e.g. birds) and typically examining a handful of loci. Here, we apply a genome-wide comparative phylogeographic approach to test hypotheses of codiversification of freshwater fishes in the trans-Andean region. Using target capture methods, we examined exon data for over 1,000 loci combined with complete mitochondrial genomes to study the phylogeographic history of five primary fish species (>150 individuals) collected from eight major river basins in Northwestern South America and Lower Central America. To assess their patterns of genetic structure, we inferred genealogical concordance taking into account all major aspects of phylogeography (within loci, across multiple genes, across species and among biogeographic provinces). Based on phylogeographic concordance factors, we tested four a priori biogeographic hypotheses, finding support for three of them and uncovering a novel, unexpected pattern of codiversification. The four emerging inter-riverine patterns are as follows: (a) Tuira + Atrato, (b) Rancheria + Catatumbo, (c) Magdalena system and (d) Sinu + Atrato. These patterns are interpreted as shared responses to the complex uplifting and orogenic processes that modified or sundered watersheds, allowing codiversification and speciation over geological time. We also find evidence of cryptic speciation in one of the species examined and instances of mitochondrial introgression in others. These results help further our knowledge of the historical geographic factors shaping the outstanding biodiversity of the Neotropics.

Made available in DSpace on 2022-05-01T09:47:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 The Neotropics harbor the most species-rich freshwater fish fauna on the planet, but the timing of that exceptional diversification remains unclear. Did the Neotropics accumulate species steadily throughout their long history, or attain their remarkable diversity recently? Biologists have long debated the relative support for these museum and cradle hypotheses, but few phylogenies of megadiverse tropical clades have included sufficient taxa to distinguish between them. We used 1288 ultraconserved element loci spanning 293 species, 211 genera, and 21 families of characoid fishes to reconstruct a new, fossil-calibrated phylogeny and infer the most likely diversification scenario for a clade that includes a third of Neotropical fish diversity. This phylogeny implies paraphyly of the traditional delimitation of Characiformes because it resolves the largely Neotropical Characoidei as the sister lineage of Siluriformes (catfishes), rather than the African Citharinodei. Time-calibrated phylogenies indicate an ancient origin of major characoid lineages and reveal a much more recent emergence of most characoid species. Diversification rate analyses infer increased speciation and decreased extinction rates during the Oligocene at around 30 Ma during a period of mega-wetland formation in the proto-Orinoco-Amazonas. Three species-rich and ecomorphologically diverse lineages (Anostomidae, Serrasalmidae, and Characidae) that originated more than 60 Ma in the Paleocene experienced particularly notable bursts of Oligocene diversification and now account collectively for 68% of the approximately 2150 species of Characoidei. In addition to paleogeographic changes, we discuss potential accelerants of diversification in these three lineages. While the Neotropics accumulated a museum of ecomorphologically diverse characoid lineages long ago, this geologically dynamic region also cradled a much more recent birth of remarkable species-level diversity. [Biodiversity; Characiformes; macroevolution; Neotropics; phylogenomics; ultraconserved elements.] Department of Structural and Functional Biology Institute of Biosciences São Paulo State University Department of Fisheries Wildlife and Conservation Sciences Oregon State University Department of Ecology and Evolutionary Biology Yale University Sector of Zoology Institute of Biosciences São Paulo State University Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Valle del Cauca Department of Ichthyology American Museum of Natural History Instituto de Biologiìa Universidad Nacional Autónoma de Mexico School of Biological Sciences Monash University Department of Biological Sciences and Museum of Natural Science Louisiana State University Cornell Lab of Ornithology Cornell University Museum of Vertebrates Department de Biología Facultad de Ciencias Pontificia Universidad Javeriana Faculdade de Filosofia Ciências e Letras Universidade de São Paulo SP Department of Ecology and Evolutionary Biology University of California Department of Structural and Functional Biology Institute of Biosciences São Paulo State University Sector of Zoology Institute of Biosciences São Paulo State University

We report two mitochondrial genomes of headstanders, derived from target capture and Illumina sequencing (HiSeq 2500 PE100). One trans-Andean species Megaleporinus muyscorum (mitochondrial consensus genome of 25 individuals) from Colombia and one cis-Andean species M. obtusidens from Argentina. Regarding M. muyscorum, mitochondrial genome has 13 protein-coding genes, 1 D-loop, 2 ribosomal RNAs, 21 transfer RNAs, and is 14,434 bp in length, for M. obtusidens mitochondrial genome has 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and is 15,546 bp in length.

Catfishes of the family Astroblepidae form a group composed by 82 valid species of the genus Astroblepus inhabiting high-gradient streams and rivers throughout tropical portions of the Andean Cordillera. Little has been advanced in the systematics and biodiversity of astroblepids other than an unpublished thesis, a single regional multilocus study and isolated species descriptions. Here, we examined 208 specimens of Astroblepus that apparently belong to 16 valid species from several piedmont rivers from northern Colombia to southern Peru. Using three single-locus approaches for species delimitation in combination with a species tree analysis estimated from three mitochondrial genes, we identified a total of 25 well-delimited lineages including eight valid and 17 potential undescribed species distributed in two monophyletic groups: the Central Andes Clade, which contains 14 lineages from piedmont rivers of the Peruvian Amazon, and the Northern Andes Clade with 11 lineages from trans- and cis-Andean rivers of Colombia and Ecuador, including the Orinoco, Amazon, and Magdalena-Cauca basins and Pacific coastal drainages. Results of species delimitation methods highlight several taxonomical incongruences in recently described species denoting potential synonymies. RESUMEN Los bagres de la familia Astroblepidae son un grupo compuesto por 82 especies válidas del género Astroblepus que habitan quebradas y ríos de alto gradiente a través de la porcion tropical en la Cordillera de los Andes. Poco se ha avanzado en la sistemática y biodiversidad de los astroblepidos aparte de una tesis no publicada, un único estudio multilocus regional y descripciones aisladas de especies. Aquí, examinamos 208 especímenes de Astroblepus que aparentemente pertenecen a 16 especies válidas provenientes de ríos de pie de monte de la cordillera de los Andes, desde el norte de Colombia hasta el sur de Perú. Utilizando tres metodologías de delimitación de especies para un único locus en combinación con análisis de un árbol de especies a partir de tres genes mitocondriales, identificamos un total de 25 linajes bien definidos que incluyen ocho especies válidas y 17 potenciales especies no descritas distribuidas en dos grupos monofiléticos: un clado de los andes centrales, que contiene 14 especies de los ríos de pie de monte de la Amazonía peruana y un clado de los andes del norte con 11 especies de los ríos trans y cisandinos de Colombia y Ecuador, incluyendo las cuencas del Orinoco, Amazonas y Magdalena-Cauca así como drenajes costeros del Pacífico. Los resultados de los métodos de delimitación de especies destacan varias incongruencias taxonómicas en especies recientemente descritas que denotan posibles sinonimias.

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-diverse ecosystem as a whole. Filling this gap was the priority of a transnational collaborative project, i.e. the AmazonFish project - https://www.amazon-fish.com/. Relying on the outputs of this project, we provide the most complete fish species distribution records covering the whole Amazon drainage. The database, including 2,406 validated freshwater native fish species, 232,936 georeferenced records, results from an extensive survey of species distribution including 590 different sources (e.g. published articles, grey literature, online biodiversity databases and scientific collections from museums and universities worldwide) and field expeditions conducted during the project. This database, delivered at both georeferenced localities (21,500 localities) and sub-drainages grains (144 units), represents a highly valuable source of information for further studies on freshwater fish biodiversity, biogeography and conservation., Measurement(s)Diversity • Fish • spatial patternTechnology Type(s)digital curationFactor Type(s)geographic locationSample Characteristic - OrganismfishSample Characteristic - Environmentdrainage basinSample Characteristic - LocationAmazon Basin Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11920800

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify biodiversity hotspots based on 6 conservation templates (3 proactive, 1 reactive, 1 representative, and 1 balanced) to provide a set of alternative planning solutions for freshwater fish protection in the Amazon Basin. We identified empirically for each template the 17% of sub-basins that should be conserved and performed a prioritization analysis by identifying current and future (2050) threats (i.e., degree of deforestation and habitat fragmentation by dams). Two of our 3 proactive templates had around 65% of their surface covered by protected areas; high levels of irreplaceability (60% of endemics) and representativeness (71% of the Amazonian fish fauna); and low current and future vulnerability. These 2 templates, then, seemed more robust for conservation prioritization. The future of the selected sub-basins in these 2 proactive templates is not immediately threatened by human activities, and these sub-basins host the largest part of Amazonian biodiversity. They could easily be conserved if no additional threats occur between now and 2050.Puntos Calientes de Diversidad de Peces de Agua Dulce para las Prioridades de Conservación en la Cuenca del Amazonas Resumen Cada día, la conservación de los hábitats de agua dulce y su biodiversidad en la cuenca del Amazonas es un reto creciente de cara a los rápidos cambios antropogénicos. Usamos la base de datos de presencia de peces más completa que existe (2,355 especies válidas; 21,248 puntos de muestreo) y tres criterios ecológicos (carácter irremplazable, representatividad y vulnerabilidad) para identificar los puntos calientes de biodiversidad con base en seis patrones de conservación (tres proactivos, uno reactivo, uno representativo y uno balanceado) y así proporcionar un conjunto de soluciones alternativas para la planeación de la protección de peces de agua dulce en la cuenca del Amazonas. Identificamos para cada patrón de manera empírica el 17% de las subcuencas que deberían conservarse y realizamos un análisis de priorización identificando amenazas actuales y a futuro (2050) (es decir, grado de deforestación y fragmentación del hábitat causado por presas). Dos de nuestros tres patrones proactivos tuvieron alrededor del 65% de su superficie cubierta por áreas protegidas; niveles altos de carácter irremplazable (60% de especies endémicas) y de representatividad (71% de la fauna ictiológica del Amazonas); y una vulnerabilidad baja actual y a futuro. Entonces, estos dos patrones parecen estar más completos para la priorización de la conservación. El futuro de las subcuencas en estos dos patrones proactivos no está amenazado por las actividades humanas a corto plazo. Además, estas subcuencas albergan la mayor parte de la biodiversidad amazónica. Se podrían conservar fácilmente si ninguna amenaza adicional sucede entre ahora y el 2050.

Hemibrycon iqueima sp. nov., is described from small streams in the Magdalena drainage at the foothills of the western slope of the Eastern Cordillera of the Colombian Andes, Suarez municipality, Tolima Department, Colombia. The new species is distinguished from its congeners in the Magdalena-Cauca River basin by a combination of characters related to snout-anal-fin origin length, head length, dorsal-pectoral fin distance, dorsal-fin-hypural distance, postorbital distance, orbital diameter, snout length, number of total vertebrae, pre-dorsal scales, scale rows between anal-fin origin and lateral line, number of branched rays of the anal fin, maxillary teeth number and number and arrangement of hooks on the branched rays of the pectoral and dorsal fins. In addition, the validity of this species is supported by previous molecular analyses that included specimens of the new species that had been erroneously identified. Phylogenetic relationships between the new species and congeners from Pacific coast basins are discussed.

A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America at 3400 km2. Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity. The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development. The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements. As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale (∼ 1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. In the case of the Mompós Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry years and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.

The Cusiana River sub-basin has been identified as a priority conservation area in the Orinoco region in Colombia due to its high species diversity. This study presents an updated checklist and identification key for fishes of the Cusiana River sub-basin. The checklist was assembled through direct examination of specimens deposited in the main Colombian ichthyological collections. A total of 2020 lots from 167 different localities from the Cusiana River sub-basin were examined and ranged from 153 to 2970 m in elevation. The highest number of records were from the piedmont region (1091, 54.0 %), followed by the Llanos (878, 43.5 %) and Andean (51, 2.5 %). 241 species distributed in 9 orders, 40 families, and 158 genera were found. The fish species richness observed (241), represents 77.7 % of the 314 estimated species (95 % CI=276.1-394.8). The use of databases to develop lists of fish species is not entirely reliable; therefore taxonomic verification of specimens in collections is essential. The results will facilitate comparisons with other sub-basins of the Orinoquia, which are not categorized as areas of importance for conservation in Colombia.ResumenLa sub-cuenca del rio Cusiana ha sido designada como una de las áreas prioritarias para la conservación en la región del Orinoco en Colombia debido a su alta diversidad de especies. Este estudio presenta una lista actualizada y una clave de identificación para los peces del área. Para ello se revisaron los especímenes depositados en las principales colecciones ictiológicas colombianas. Se examinaron un total de 2020 lotes de 167 localidades diferentes de la sub-cuenca del río Cusiana, que oscilaron entre 153 y 2970 m en altitud. El mayor número de registros corresponde a la región del piedemonte (1091, 54.0%), seguida por los Llanos (878, 43.5%) y Andina (51, 2.5%). Encontramos 241 especies distribuidas en 9 órdenes, 40 familias y 158 géneros. La riqueza de especies de peces observada (241), representan el 77.7% de las 314 especies estimadas (IC 95% = 276.1-394.8). El uso de bases de datos para elaborar listas de especies de peces no es del todo fiable, por lo tanto, es esencial la verificación taxonómica de los especímenes en las colecciones. Estos resultados permitirán evaluar otras sub-cuencas de la Orinoquia, las cuales no están categorizadas como áreas de importancia para la conservación en Colombia.

The present work is part of a process to create a Catalogue of the Freshwater Fishes of Colombia and consisted in the depuration and updating of the taxonomic and geographic components of the checklist of the freshwater fishes of Colombia. An exhaustive revision of the 1435 species recorded in 2008 was necessary to: 1. Add new species described since 2009 and species originally described from Colombia but inadvertently omitted in 2008; 2. Add new records of already described species; 3. Delete species whose presence in Colombia was not supported by voucher specimens in ichthyological collections; and 4. Revise the geographic distribution of the species listed in 2008. This process resulted in the following numbers: 1. Total number of freshwater fish species in Colombia: 1494; 2. Number of species recorded by hydrographic region - Amazon: 706, Orinoco: 663, Caribbean: 223, Magdalena-Cauca: 220, Pacific: 130; and 3. Number of endemic species: 374 (76% from the trans-Andean region). Updating the current checklist is a fundamental requirement to ensure its incorporation in the decision-making process with regard to the conservation of Colombian aquatic species and ecosystems, which are facing transformation processes as a result of activities such as mining, construction of hydroelectric plants, expansion of the agricultural frontier and subsequent deforestation, industrial and domestic pollution, development of waterways, introduction of exotic species, and climate change.ResumenEl presente trabajo es parte de un proceso para crear un Catálogo de Peces de Agua Dulce de Colombia y consistió en la depuración y actualización de los componentes taxonómico y geográfico del listado de peces de agua dulce de Colombia. Una revisión exhaustiva de las 1435 especies registradas en 2008 fue necesaria para: 1. Adicionar las especies nuevas descritas desde 2009 y especies descritas originalmente para Colombia pero omitidas inadvertidamente en 2008; 2. Adicionar nuevos registros de especies ya descritas; 3. Eliminar especies cuya presencia en Colombia no estaba soportada por especímenes en colecciones ictiológicas; y 4. Revisar la distribución geográfica de las especies listadas en 2008. Este proceso resultó en las siguientes cifras: 1. Número total de especies de peces de agua dulce en Colombia: 1494; 2. Número de especies registradas por región hidrográfica - Amazonas: 706, Orinoco: 663, Caribe: 223, Magdalena-Cauca: 220, Pacífico: 130; y 3. Número de especies endémicas 374 (76% distribuidas en la región transandina). La actualización del presente listado es un requerimiento fundamental para asegurar su incorporación en el proceso de toma de decisiones en lo concerniente a la conservación de las especies y ecosistemas acuáticos colombianos, los cuales están enfrentando procesos de transformación, como resultado de actividades como la minería, construcción de plantas hidroeléctricas, expansión de la frontera agropecuaria y subsecuente desforestación, polución industrial y doméstica, desarrollo de hidrovías, introducción de especies exóticas y cambio climático.

Tropical rivers are experiencing an unprecedented boom in dam construction. Despite rapid dam expansion, knowledge about the ecology of tropical rivers and the implications of existing and planned dams on freshwater-dependent species remains limited. Here we evaluate fragmentation of fish species ranges, considering current and planned dams of the Magdalena River basin, Colombia. We quantify the relationship between species range and body size and use a vulnerability limit set by this relationship to explore the influence that fragmentation of species ranges has on extinction risk. We find that both existing and planned dams fragment most fish species ranges splitting, them into more vulnerable populations. Importantly, we find that migratory species, and those that support fisheries, are most affected by fragmentation. Our results highlight the dramatic impact that dams can have on freshwater fishes and offer insights into species extinction risk for data-limited regions. This article is protected by copyright. All rights reserved

Upstream range shifts of freshwater fishes have been documented in recent years due to ongoing climate change. River fragmentation by dams, presenting physical barriers, can limit the climatically induced spatial redistribution of fishes. Andean freshwater ecosystems in the Neotropical region are expected to be highly affected by these future disturbances. However, proper evaluations are still missing. Combining species distribution models and functional traits of Andean Amazon fishes, coupled with dam locations and climatic projections (2070s), we (a) evaluated the potential impacts of future climate on species ranges, (b) investigated the combined impact of river fragmentation and climate change and (c) tested the relationships between these impacts and species functional traits. Results show that climate change will induce range contraction for most of the Andean Amazon fish species, particularly those inhabiting highlands. Dams are not predicted to greatly limit future range shifts for most species (i.e., the Barrier effect). However, some of these barriers should prevent upstream shifts for a considerable number of species, reducing future potential diversity in some basins. River fragmentation is predicted to act jointly with climate change in promoting a considerable decrease in the probability of species to persist in the long-term because of splitting species ranges in smaller fragments (i.e., the Isolation effect). Benthic and fast-flowing water adapted species with hydrodynamic bodies are significantly associated with severe range contractions from climate change.

Functional variation in rhodopsin, the dim-light-specialized visual pigment, frequently occurs in species inhabiting light-limited environments. Variation in visual function can arise through two processes: relaxation of selection or adaptive evolution improving photon detection in a given environment. Here, we investigate the molecular evolution of rhodopsin in Gymnotiformes, an order of mostly nocturnal South American fishes that evolved sophisticated electrosensory capabilities. Our initial sequencing revealed a mutation associated with visual disease in humans. As these fishes are thought to have poor vision, this would be consistent with a possible sensory trade-off between the visual system and a novel electrosensory system. To investigate this, we surveyed rhodopsin from 147 gymnotiform species, spanning the order, and analysed patterns of molecular evolution. In contrast with our expectation, we detected strong selective constraint in gymnotiform rhodopsin, with rates of non-synonymous to synonymous substitutions lower in gymnotiforms than in other vertebrate lineages. In addition, we found evidence for positive selection on the branch leading to gymnotiforms and on a branch leading to a clade of deep-channel specialized gymnotiform species. We also found evidence that deleterious effects of a human disease-associated substitution are likely to be masked by epistatic substitutions at nearby sites. Our results suggest that rhodopsin remains an important component of the gymnotiform sensory system alongside electrolocation, and that photosensitivity of rhodopsin is well adapted for vision in dim-light environments.

This paper describes the Photafish System, an innovative technique for capturing high-quality digital images of live freshwater fishes and other aquatic organisms in the field. This system may improve and facilitate the visual documentation of such organisms to illustrate guidebooks, populate online databases and support scientific papers, particularly taxonomic ones. The system was designed and tested to produce Taxonomically Informative Photos (TIPs) of living specimens and employs an Aquarium Assembly for Photography (AAP) distinguished by its portability and low cost. Using Neotropical freshwater fishes as a model, we propose an optimized protocol for documenting the morphology of live specimens to support taxonomy, as well as awareness and conservation of freshwater biodiversity. This paper addresses the technical aspects and challenges of field studio photography in remote locations. Tricks gleaned from personal experiences with nature photography are also shared. Finally, we briefly discuss the advantages and weaknesses of our approach.

The present study describes ecological aspects of Lebiasina erythrinoides; 200 individuals were sampled throughout an annual hydrological cycle from October 2008 to September 2009 in La Calaboza stream, a Piedmont tributary of the Rio Cravo Sur. The studied population had more females than males (1.5:1) and preferred habitats dominated by shoreline vegetation and rocky substrates. Prior to reproductive events, individuals presented an increase in the condition factor (K) and the gonosomatic index (GSI). On average, 648.8 oocytes are discharged twice a year: at the beginning of the rainy season, and during falling water phase. The mean sizes at sexual maturity found for females were 73.5 mm standard length (SL) and for males 70 mm SL. Rounding up, an average minimum size of capture of 75 mm SL is proposed. Most specimens of the population (65 %) were found to be maturing or mature (stages II and III), 28.5 % immature (stage I), 5.0 % in post reproduction stage V, and 1.5 % in reproductive phase (IV). Results suggest this species is omnivorous with a preference for invertebrates (IRI = 41.2 %) and vegetal material (IRI = 27.8 %), but also includes a variety of other items. The values of the diet are correlated with hydrological cycle and size.

Hydropower development in the Andean Amazon has been underestimated and will disrupt connected human and natural systems., Andes-to-Amazon river connectivity controls numerous natural and human systems in the greater Amazon. However, it is being rapidly altered by a wave of new hydropower development, the impacts of which have been previously underestimated. We document 142 dams existing or under construction and 160 proposed dams for rivers draining the Andean headwaters of the Amazon. Existing dams have fragmented the tributary networks of six of eight major Andean Amazon river basins. Proposed dams could result in significant losses in river connectivity in river mainstems of five of eight major systems—the Napo, Marañón, Ucayali, Beni, and Mamoré. With a newly reported 671 freshwater fish species inhabiting the Andean headwaters of the Amazon (>500 m), dams threaten previously unrecognized biodiversity, particularly among endemic and migratory species. Because Andean rivers contribute most of the sediment in the mainstem Amazon, losses in river connectivity translate to drastic alteration of river channel and floodplain geomorphology and associated ecosystem services.

A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America. Annual large-scale inundation of floodplains and associated wetlands regulates water-, nutrient-, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we present a comparative analysis of the potential effects of hydropower expansion to meet projected electricity requirements by 2050, in terms of 1) basin-level implications of cumulative changes in streamflow regime, sediment trapping, and loss of river connectivity, and 2) the impact of upstream regulation on the hydrologic dynamics of the Mompós Depression wetlands at a monthly to decadal scale. To this end, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the Mompós Depression floodplains water balance at a medium scale (~1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. Our results indicate that potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry periods and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.

Made available in DSpace on 2019-10-06T16:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-06-01 Advanced Manufacturing Office Vicerrectoría de Investigación, Universidad de Costa Rica Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) CYTED Ciencia y Tecnología para el Desarrollo General Motors Corporation Accurate species delimitation is crucial for studies of phylogeny, phylogeography, ecology, conservation and biogeography. The limits of species and genera in the Characidae family are controversial due to its uncertain phylogenetic relationships, high level of morphological homoplasy and the use of ambiguous morphological characters for descriptions. Here we establish species boundaries for Bryconamericus, Hemibrycon, Knodus and Eretmobrycon (Stevardiinae: Characidae), previously diagnosed with morphology, using three different barcoding approaches (GMYC, PTP, ABGD). Results revealed that species delimitation was successful by the use of a single-gene approach and by following a workflow in the context of integrative taxonomy, making evident problems and mistakes in the cataloging of Characidae species. Hence, it was possible to infer boundaries at genus level for clusters in the trees (GMYC and PTP) and automatic partitions (ABGD) which were consistent with some of recent taxonomic changes proposed in Characidae. We found that discordance cases between methods were linked to limitations of the methods and associated to putative species cluster closely related, some historically problematic in their diagnosis and identification. Furthermore, we suggested taxonomic changes and possibly new species, revealing a high degree of hidden diversity. Finally, we propose a workflow as a fast, accurate and objective way to delimit species from mitochondrial DNA sequences and to help clarify the classification of this group. Laboratorio de Ictiología Unidad de Ecología y Sistemática (UNESIS) Departamento de Biología Facultad de Ciencias Pontificia Universidad Javeriana Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista (UNESP) Campus de Botucatu Universidade Santo Amaro Rua Prof. Enéas de Siqueira Neto Jardim das Imbuias Centro de Ciências da Vida e da Natureza Universidade Federal da Integração Latino-Americana–UNILA Programa de Biología Ambiental Facultad de Ciencias Naturales y Matemáticas Universidad de Ibagué Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista (UNESP) Campus de Botucatu Vicerrectoría de Investigación, Universidad de Costa Rica: 00006552 FAPESP: 2010/17009-2 CNPq: 306054/2006-0 CYTED Ciencia y Tecnología para el Desarrollo: 567/2012

The Grundulus bogotensis is an Endangered fish in Colombia. In this study, we report the complete mitochondrial DNA sequences of G. bogotensis. The entire genome comprised 17.123 bases and a GC content of 39.84%. The mitogenome sequence of G. bogotensis would contribute to better understand population genetics, and evolution of this lineage. Molecule was deposited at the GenBank database under the accession number KM677190.

Akawaio penak, a new genus and species, is described from the upper Mazaruni River, Guyana. The new species is diagnosed from all other species of Hypopomidae by several anatomical traits. The phylogenetic affinities of the new genus were inferred using data from one nuclear (rag2) and two mitochondrial (COI and cyt b) genes. The phylogenetic analyses indicate that Akawaio is the sister taxon of a clade that includes Brachyhypopomus, Hypopomus, Microsternarchus and Racenisia. These results provide evidence for the phylogenetic composition of Hypopomidae supported by previous molecular studies and support the position of the Steatogenini (Hypopygus + Steatogenys) as the sister group of Rhamphichthys + Gymnorhamphichthys. The description of this new electric knifefish increases the total number of endemic genera and species in the upper Mazaruni, a region that is suffering freshwater habitat degradation as consequence of gold-mining activities.