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Phylogenetic analyses of mitochondrial and nuclear data of 31 specimens of Cyphocharax from trans-Andean rivers support the presence of one lineage of Cyphocharax aspilos in Lago Maracaibo and three cryptic lineages of Cyphocharax magdalenae: (1) Cauca-Magdalena and Ranchería, (2) León and Atrato, and (3) Chucunaque-Tuira, Santa María, and Chiriquí basins of Central America. Results suggest that the Serranía del Perijá facilitated Late Miocene cladogenetic events, whereas post-Isthmian C. magdalenae expansion was enabled by gene flow across the lower Magdalena valley and Central American lowlands. Time-calibrated phylogenetics indicate that the C. magdalenae colonized lower Central America in the Pliocene (3.7 MYA; Ma), the divergence Atrato-Magdalena occurred in Late Pliocene (3.0 Ma) and the split Ranchería-Magdalena during the Middle Pleistocene (1.3 Ma). Updated geographic distribution data support the hypothesis that the Cordillera de Talamanca functions as a barrier to northward expansion of C. magdalenae in Central America.

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CONTEXT: Anecdotal experience of Magdalena energy session(s) offers some indication of its health benefits, yet the literature on this new energy healing modality is scarce. OBJECTIVE: To explore the personal experience of recipients of the Magdalena energy session(s). METHOD: In-depth interviews were conducted with 25 generally healthy volunteer adults from around the world who had received at least one Magdalena energy healing session with a certified Magdalena practitioner. Thematic analysis was used to discern patterns in the experience. RESULTS: Participants had different motives for attending the Magdalena energy session(s). Clients reported experiencing movement and release of energy, changes in sensation and feeling, and transcendental experience during the Magdalena energy session(s). After the session(s), there were reports of a sustained feeling of lightness, increased positive emotions, increased self-awareness, and deeper spiritual connection. Participants noted the uniqueness of the Magdalena energy session(s) compared to other energy healing practices. CONCLUSION: The findings from this qualitative study suggest that Magdalena energy session(s) can elicit a relaxation response, alter emotions, and increase spiritual connections to facilitate a subjective healing experience. Therefore, the present study recommends further investigations to elucidate variables for a larger-scale intervention study of the effects of Magdalena energy session(s) on health outcomes and the underlying mechanisms of action.

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BACKGROUND: Energy healing techniques are associated with many physical and mental benefits. A qualitative study was conducted to understand clients' experiences of a new energy healing modality called Magdalena Energy Healing. METHODS: Semi-structured qualitative interviews were conducted after clients experienced 60 min Magdalena energy healing session(s). Twenty-five adults participated in the study. All participants received Magdalena energy healing from a certified, trained practitioner. Thematic analysis was conducted to determine clients' perceived benefits of the Magdalena energy healing session(s). RESULTS: Four themes emerged from the data: Physical, Mental, Social, and Spiritual Benefits. Physical health benefits included relief from a variety of medical symptoms, improved sleep quality, and physical body awareness. Mental Health benefits included relaxation and peace, decision-making clarity, relief of mental health symptoms, and an increased ability to cope with life. Social Benefits included improved attitudes in relationships. Spiritual Benefits included optimism, gratitude, self-acceptance, and increased spiritual connection. CONCLUSIONS: Participants' perceptions are that Magdalena energy healing sessions offer peace, symptom relief, and gratitude. Magdalena energy healing can address priorities of The National Center for Complementary and Integrative Health (NCCIH). Sessions can be seamlessly integrated into traditional medical care as a useful complementary/integrative healing option to improve physical, mental, and/or spiritual wellbeing across a variety of diseases.

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Resumen Introducción: Las ciénagas hacen parte de la llanura de inundación de un río y son influenciadas por el pulso de inundación, fuerza que modula los cambios anuales en las variables bióticas y abióticas. Los ensambles biológicos tienen diferentes respuestas a este pulso y podrían presentar cambios en la composición y abundancia. Objetivo: Evaluar cómo se modifican las condiciones físico-químicas en los microambientes de vegetación flotante y el ensamble de ostrácodos a lo largo de un pulso de inundación en la Ciénaga Río Viejo, Santander, Colombia. Métodos: Se caracterizaron las variables físico-químicas de los microambientes de plantas acuáticas flotantes durante las cuatro fases hidrológicas del pulso de inundación: aguas bajas, altas, ascenso y descenso, en tres estaciones donde el pulso tuvo mayor efecto. Ostrácodos dulceacuícolas fueron recolectados de estos microambientes, identificados y contados. Resultados: Las condiciones ambientales dentro de los microhábitats fluctuaron siguiendo el pulso de inundación en el sistema. Se encontraron tres familias taxonómicas y seis especies de ostrácodos. No hubo diferencias en la composición y abundancia del ensamble de ostrácodos en el espacio y el tiempo, lo que sugiere que están protegidas contra los cambios ambientales causados por las fluctuaciones hidrológicas. La abundancia de especies cambió en respuesta a la variabilidad ambiental. Strandesia cf. sphaeroidea y Keysercypria sp. 2 están asociadas con aguas más someras y con mayor cobertura de vegetación acuática densa. Otras especies mostraron ser tolerantes a fluctuaciones hidrológicas y pueden estar relacionadas con la plasticidad ecológica, como Cytheridella ilosvayi, Diaphanocypris meridana y Stenocypris major, que han sido registradas en una variedad de ambientes acuáticos y con distribuciones a escala continental. Conclusiones: Los pulsos de inundación indujeron cambios ambientales en la Ciénaga de Río Viejo, pero los microhábitats con cobertura de vegetación flotante parecen estar protegidos contra el pulso hidrológico, permitiendo así que las comunidades de ostrácodos permanezcan casi sin alteraciones durante un pulso de inundación. Este conjunto de datos actualizado de agua dulce tropical contribuye a llenar los vacíos de conocimiento relacionados con la idoneidad del hábitat y la distribución de las comunidades de ostrácodos en Colombia.

Abstract Introduction: Swamps are lowland shallow tropical lakes in rivers floodplains, characterized by annual flood pulses that modulate changes in biotic and abiotic variables. Biological assemblages have different responses to flood pulses, remaining either undisturbed or with significant changes in composition and abundance. Objective: To evaluate how physical and chemical conditions are modified in mixed macrophytes microenvironments and ostracod species assemblages throughout a flood pulse in Rio Viejo swamp, Santander, Colombia. Methods: We characterized physical and chemical variables of microenvironments of aquatic floating plants, during four different hydrologic periods of the flood pulse: low, high, rising, and descending waters, at three stations where the flood pulse have the most important effect. Freshwater ostracods were collected from such microenvironments, identified, and counted. Results: Environmental conditions within microhabitats fluctuated following the flood pulse in the system. Three taxonomic families and six species of ostracods were observed. No differences in the composition and abundance of the spatio-temporal ostracod assemblages were observed, suggesting that they are buffered against environmental changes driven by hydrological fluctuations. Species abundance changed in response to environmental variability. Species such as Keysercypria sp. and Keysercypria sp. 2 are associated to shallower waters and more likely to dense aquatic vegetation cover. Other species showed to be more tolerant to hydrological fluctuations and may be related to ecological plasticity, species such as Cytheridella ilosvayi, Diaphanocypris meridana and Stenocypris major that have been recorded in a variety of aquatic environments and with distributions at continental scale. Conclusions: Flood pulses induced environmental changes in Rio Viejo Swamp, but microhabitats in mixed macrophyte cover seems to be buffered against the hydrological pulse, thus allowing almost undisturbed ostracod assemblages throughout a flood pulse. This updated tropical freshwater dataset contributes towards filling the knowledge gaps related to habitat suitability and distribution of ostracods communities in Colombia.

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Resumen Introducción: La Rata de Magdalena, Xenomys nelsoni, es un roedor endémico de México, de distribución restringida a las selvas bajas caducifolias densas, en una pequeña región de la costa del Pacífico mexicano. Es una especie poco conocida, catalogada como "En Peligro" de acuerdo con la Unión Internacional para la Conservación de la Naturaleza (IUCN). Este desconocimiento unido a la alta tasa de deforestación de su hábitat hace que su conservación sea prioritaria. Objetivo: Realizar un recuento histórico de los registros depositados en las colecciones científicas, generar mapas de distribución potencial y analizar el estado de conservación de la especie. Método: Los datos de ocurrencia de las especies se obtuvieron de la literatura y bases de datos digitales y se analizaron por décadas. Se utilizaron los programas GARP y MaxEnt para generar los modelos de nicho ecológico. La importancia de las variables en el modelo se estimó mediante un análisis Jackknife. Resultados: A lo largo de 129 años 19 recolectores registraron 69 ejemplares, de los cuales 65 están depositados en siete colecciones internacionales y una nacional. Aunque la especie sólo se ha recolectado en Jalisco y Colima, la distribución potencial de X. nelsoni incluye también el estado de Michoacán. De esta área estimada, sólo el 1.5 % se encuentra dentro de un Área Natural Protegida. Conclusiones: Los resultados de la distribución potencial podrían ser utilizados para verificar la presencia de la especie en lugares donde no ha sido recolectada como el norte de la Reserva de la Biosfera Chamela-Cuixmala y en algunas zonas de la provincia fisiográfica Costas del Sur en el estado de Michoacán. Es necesario incrementar los muestreos en regiones poco estudiadas predichas por el modelo y aumentar el área de protección.

Abstract Introduction: The Magdalena Rat, Xenomys nelsoni, is a rodent endemic to Mexico, whose distribution is restricted to dense tropical dry forests in a small region on the Pacific coast of Mexico. It is a poorly known species categorized as "Endangered" by the International Union for Conservation of Nature (IUCN). This lack of knowledge and the high rates of deforestation of its habitat makes its conservation a priority. Objective: To summarize the historical records deposited in scientific collections, to create potential distribution maps, and to analyze the conservation status of the species. Methods: We obtained species occurrence data from literature and digital databases, analyzing them by the decade. We used GARP and MaxEnt software to generate the ecological niche models. The importance of the variables in the model was estimated using the Jackknife technique. Results: Over 129 years, 19 collectors registered 69 specimens, of which 65 are deposited in one national and seven international collections. Although the species has only been collected in Jalisco and Colima, the potential distribution for X. nelsoni also includes the state of Michoacán. Of this estimated area, only 1.5 % is in a Protected Natural Area. Conclusions: The results of the potential distribution could be used to verify the presence of the species in places where it has not been collected, such as the northern part of the Chamela-Cuixmala Biosphere Reserve and in some areas of the physiographic province Costas del Sur in the state of Michoacán. It is needed to increase samplings in the least studied regions predicted by the model and expand the area of protection.

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Introducción: Las charcas temporales son ecosistemas acuáticos variables en su estructura física y biótica, efímeros en el paisaje e importantes en el flujo de materia y energía. Los macroinvertebrados acuáticos constituyen el grupo más abundante y diverso en estos ecosistemas y requieren mayor estudio, particularmente en los trópicos. Objetivo: Evaluar la diversidad alfa y beta de las comunidades de macroinvertebrados acuáticos de seis charcas temporales durante dos épocas climáticas en el norte de Colombia. Métodos: En Magdalena, Colombia, hicimos seis arrastres aleatorios con redes manuales en la zona litoral, y seis arrastres en zigzag con redes tipo D en la zona lacustre; recolectamos macrofauna en tres lances con una draga Ekman; y muestreamos cada charca durante la alta precipitación (noviembre, 2020) y la baja precipitación (febrero, 2021). Resultados: Identificamos 3 358 individuos (13 órdenes, 39 familias y 68 géneros). La mayor abundancia y diversidad (N= 485, 0D= 32) durante la época de lluvia se presentó en Los Campanos, mientras que la charca Villa Leidy tuvo el mayor número de taxones comunes (18) y dominantes (14). En la época de sequía, la charca Los Trillizos presentó la mayor abundancia (533) y diversidad (43); mientras que Villa Leidy y El Miquito el mayor número de taxones dominantes (16). Las charcas tienen composiciones particulares (sin agrupamientos espaciales o temporales); el recambio de taxones es alto, y la correspondencia canónica se agrupa por temporada. Conclusiones: la composición de las comunidades de macroinvertebrados acuáticos de las charcas temporales son muy diversas, presentando alto recambio tanto espacial como temporal, reflejando altos valores de remplazo de taxones entre épocas climáticas. La zona litoral mantuvo una composición similar durante las dos temporadas.

Introduction: Temporary ponds are variable aquatic ecosystems in their physical and biotic structure, ephemeral in the landscape and important in the flow of matter and energy. Aquatic macroinvertebrates constitute the most abundant and diverse group in these ecosystems and need further study, particularly in the tropics. Objective: To evaluate the alpha and beta diversity of the aquatic macroinvertebrate communities of six temporary pools during two climatic seasons in Northern Colombia. Methods: In Magdalena, Colombia, we did six random trawls with hand nets in the coastal zone, and six zig zag trawls with D nets in the lacustrine zone; we collected macrofauna in three random hauls with an Ekman dredge; and sampled each pond in high rainfall (November 2020) and low rainfall (February 2021). Results: We identified 3 358 individuals (13 orders, 39 families and 68 genera). The highest rainy season abundance and diversity (N= 485, 0D= 32) were in Los Campanos, while Villa Leidy Pond had the highest number of common (18) and dominant (14) taxa. During the dry season, Los Trillizos Pond had the highest abundance (533) and diversity (43); while Villa Leidy and El Miquito had the largest number of dominant taxa (16). The pools have a particular composition (no spatial or temporal grouping); taxa turnover is high, and the canonical correspondence clustered by season. Conclusions: The aquatic macroinvertebrate communities of the temporary ponds are diverse and have high turnover in space and time, reflecting high replacement of taxa between climatic periods. The littoral zone had a similar composition in the two seasons.

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Introduction: The distribution of freshwater fishes in the Colombian Andes results from the interaction between historical and recent factors. Currently, the Andean landscape is facing rapid transformation processes. However, the knowledge regarding species distribution and environmental requirements is advancing slower than the transformations underway in the fluvial networks. Objective: To understand the conformation of the fish assemblage in the middle and lower Cauca River basin, considering the local environmental context before the construction of the Ituango Dam, and quantifying β diversity and its two components (turnover and nestedness) amongst local fish communities. Methods: 58 localities were monitored during nine years (between February 2010 and November 2018), the period before the dam's operation. The species richness (α-diversity), species turnover (β-diversity), and assemblage composition were estimated for the given localities. Results: 114 species were recorded, representing ~ 49 % of the total richness of known species for the Magdalena basin. The richness distribution showed that the number of species varies among the aquatic environments. Swamps presented the most significant number of species, followed by the Cauca River, while streams had the lowest values of richness. The spatial analyses of β-diversity revealed a high variation component in the study area due to species replacement between the aquatic environments. Conclusions: The implementation of long-term monitoring allowed us to recognize that the Cauca River basin conserves a great variety of species-rich environments. The species turnover indicates a high proportion of endemism or multiple sites with unique species. Finally, our study will serve as a baseline to verify, over time, whether the dam's construction is associated with essential changes in the structure of fish communities.

Introducción: La distribución de los peces de agua dulce en los Andes colombianos es el resultado de la interacción entre factores históricos y recientes. Actualmente, el paisaje Andino enfrenta procesos de rápida transformación. Sin embargo, el conocimiento sobre la distribución de las especies y sus requerimientos ambientales no avanza tan rápido como las transformaciones en curso en las redes fluviales. Objetivo: Comprender la conformación del ensamble de peces en la cuenca media y baja del río Cauca, considerando el contexto ambiental local antes de la construcción de la represa de Ituango, y cuantificar la diversidad beta y sus dos componentes (recambio y anidamiento) entre las comunidades de peces locales. Métodos: Se analizaron 58 localidades durante nueve años (entre febrero 2010 y noviembre 2018), período previo a la operación de la represa. La riqueza de especies (diversidad α), el recambio de especies (diversidad β) y la composición del conjunto se estimaron para las localidades dadas. Resultados: Se registraron 114 especies, que representan ~ 49 % de la riqueza total de especies conocidas para la cuenca del Magdalena. La distribución de la riqueza mostró que el número de especies varía entre los ambientes acuáticos. Las ciénagas presentaron el mayor número de especies, seguidas por el río Cauca, mientras que las quebradas presentaron los valores más bajos de riqueza. Los análisis espaciales de la diversidad β revelaron un alto componente de variación en el área de estudio debido al reemplazo de especies entre los ambientes acuáticos. Conclusiones: La implementación del monitoreo a largo plazo permitió reconocer que la cuenca del río Cauca conserva una gran variedad de ambientes ricos en especies. El recambio de especies indica una alta proporción de endemismo o múltiples sitios con especies únicas. Finalmente, nuestro estudio servirá como línea base para verificar, con el tiempo, si la construcción de la represa está asociada con cambios esenciales en la estructura de las comunidades de peces.

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Pesticides are prevalent pollutants found in river sediments in agricultural regions worldwide, leading to environmental pollution and toxic effects on biota. In this study, twenty sediment samples were collected from the Magdalena River in Colombia and analyzed for forty pesticides. Methanolic extracts of the sediments were used to expose Caenorhabditis elegans for 24 h, evaluating the effects on its reproduction. The most abundant pesticides found in Magdalena River sediments were atrazine, bromacil, DDE, and chlorpyrifos. The concentrations of DDE and the sum of DDD, DDE, and DDT were above the Threshold Effect Concentration (TEC) values for freshwater sediments, indicating potential effects on aquatic organisms. The ratios of DDT/(DDE + DDD) and DDD/DDE suggest historical contributions of DDT and degradation under aerobic conditions. Several sampling sites displayed a moderate toxicity risk to biota, as calculated by the sediment quality guideline quotient (SQGQ). Nematode brood size was reduced by up to 37% after sediment extract exposure. The presence of chlordane, DDT-related compounds, and chlorpyrifos in Magdalena River sediments was associated with reproductive toxicity among C. elegans.

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Trace metals concentrations along with stable isotopes ratios were measured in marine algae, sea grass, sponges, echinoderms, mollusks, crustaceans, fishes, and the California sea lion, to assess the bioaccumulation potential and detect potential risks for top predators off Bahia Magdalena, Mexico. We assessed the trophic magnification factor (TMF) to determine the potential for biomagnification of 11 trace metals. The concentrations of Fe and Zn were one order of magnitude higher than all other metals. Concentrations of As, Cu, Cd, Co, Cr, Fe, Mn and Ni correlated negatively with trophic level, supporting trophic dilution (TMF < 1, p > 0.05), while Zn and Hg had significant trophic magnification (TMF > 1, p < 0.05) when assessing only the benthic-pelagic foodweb. This research provides a baseline concentration of metals in multiple species, metal-specific foodweb bioaccumulation and biomagnification of mercury, underscoring the key role of the macrobenthic community as biovectors for trophic transfer of Hg through the foodweb to the California sea lion.

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The Colombian Pacific coast is an amazing natural region, immersed in one of the most unknown biodiversity hotspots in the world. An expedition carried out in the north of this area, at the Jardín Botánico del Pacífico (JBP) in Bahía Solano, Chocó, focused on studying the diversity of the mygalomorph spider fauna, allowed us to discover four new species included in the families Halonoproctidae and Theraphosidae. The trapdoor species Ummidiasolanasp. nov., and the theraphosids species Euthycaeluscunampiasp. nov. (Schismatothelinae), Melloinapacificasp. nov. (Glabropelmatinae), and Neischnocolusmecanasp. nov. (Theraphosinae) are illustrated, diagnosed, and described in detail. Photographs of somatic features and copulatory organs and a distribution map are provided. Morphological, taxonomical, and biogeographical aspects are discussed for each species. All these taxonomic novelties represent the first records of these genera for the region, expanding the range of geographic distribution of each of them. This work constitutes the first effort focused on characterizing the community of Mygalomorphae species in the Chocó Biogeographic Region.

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We describe the change in the fish community of the Porce River in Magdalena River Basin, Colombia, following the construction of the Porce III hydropower reservoir based on 13 years of monitoring data. The results show a clear reduction of the number of native species, which have been supplanted by colonizing non-native species, especially in the reservoir. Four native species detected prior to dam construction have apparently disappeared, but 12 new species were registered post-construction. We analyzed spatial changes in beta diversity in the aquatic environments surrounding the dam. The new environment generated by the reservoir presents a unique species composition and contributes significantly to the total beta diversity of the system. Altogether three distinct new fish assemblages emerged following reservoir formation and there are now six assemblages where there had previously been three. This dramatic change, already visible within a decade of construction, highlights just how strong of an impact dam construction has on habitats and how rapidly fish communities react in this hotspot for endemic fish diversity. Our findings demonstrate the importance of monitoring fish communities for revealing the impact of damming on river ecosystems and informs potential complementary fish diversity inventories elsewhere in the Magdalena River basin.(AU)

Describimos el cambio en la comunidad de peces del río Porce en la cuenca del río Magdalena en Colombia luego de la construcción del embalse hidroeléctrico Porce III con base en 13 años de datos de monitoreo. Los resultados mostraron una reducción de especies nativas y, el embalse ha sido colonizado por especies no nativas. A lo largo del monitoreo cuatro especies desaparecieron de las capturas, y se registró la aparición de 12 especies nuevas después de la construcción del embalse. Analizamos los cambios espaciales en la diversidad beta en los ambientes acuáticos que rodean la presa. El nuevo entorno generado por el embalse presenta una composición de especies única; en total, surgieron tres nuevos ensamblajes de peces distintos después de la formación del embalse y ahora hay seis ensamblajes. Este cambio, ya visible a una década de la construcción, resalta cuán fuerte es el impacto que tiene la construcción de presas en los hábitats y cuán rápido reaccionan las comunidades de peces. Nuestros hallazgos demuestran la importancia de monitorear las comunidades de peces para revelar el impacto de las represas en los ecosistemas fluviales, además permite complementar los inventarios de diversidad en la cuenca del río Magdalena.(AU)

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This article contains methods, results, and analysis agreed for the development of an application based on the internet of things and making use of machine learning techniques that serves as a support for the identification of the saline wedge in the Magdalena River estuary, Colombia. As a result of this investigation, the process of identifying the most suitable telecommunications architecture to be installed in the estuary is shown, as well as the characteristics of the software developed called SISME (Estuary Monitoring System), and the results obtained after the implementation of prediction techniques based on time series. This implementation supports the maritime security of the port of Barranquilla since it can support decision-making related to the estuary. This research is the result of the project "Implementation of a Wireless System of Temperature, Conductivity and Pressure Sensors to support the identification of the saline wedge and its impact on the maritime safety of the Magdalena River estuary".

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Because dams block migratory routes of potamodromous fish to their spawning areas, and energy generation changes natural flow seasonality, it is necessary to identify spawning areas and their conditions. This information will help in management decisions in the Magdalena River basin regarding the future hydropower development. We identified which characteristics of the tributaries to the Magdalena River are important for determining potamodromous fish spawning grounds, and we estimated the percentage of future loss of spawning areas because of dam development. Ichthyoplankton density is directly related to the floodplain area, and inversely related with channel slope. Low channel slopes offer adult fish a longer distance for their upstream migration and a longer time for embryo development during their drift downstream from the spawning areas to nursery habitats (floodplain lakes). These features could increase the migration distance of the adults, the time for initial embryo development, and, because of its relationship with nursery habitats access, the offspring survival. The potential loss of the actual spawning grounds in the river network was estimated to be nearly 70% because of new dams. Our findings will help to reduce conflicts between hydropower and ecological interests.(AU)

La construcción de hidroeléctricas puede afectar la reproducción de los peces migratorios potamódromos, ya sea porque las represas bloquean las rutas migratorias a sus áreas de desove, o porque la generación de energía cambia la estacionalidad del flujo natural. Esto hace necesario generar información sobre las áreas de desove y sus características, que permitan tomar decisiones de manejo, teniendo en cuenta el desarrollo hidroeléctrico propuesto a futuro en la cuenca del río Magdalena. Identificamos qué características de algunos afluentes del río Magdalena son importantes para los desoves y estimamos el porcentaje de pérdida futura de áreas de desoves debido al desarrollo hidroeléctrico. La densidad del ictioplancton se relacionó directamente con el área de la llanura aluvial e inversamente con la pendiente del canal. Estas características aumentan la distancia de migración de los adultos maduros, el tiempo para el desarrollo inicial del embrión y la supervivencia de la descendencia debido a la proximidad y/o conectividad con los hábitats de cría. La pérdida potencial de las zonas de desove en la red fluvial se estimó en casi el 70% debido a las nuevas presas. Nuestros hallazgos ayudarán a tomar decisiones sostenibles para reducir los conflictos entre intereses de desarrollo hidroeléctrico y ecológicos.(AU)

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The Neotropical freshwater catfish Pseudopimelodus atricaudus and Pseudopimelodus magnus are two recently discovered species endemic to the Colombian Magdalena-Cauca River basin. In this study, a set of 13 microsatellite loci were developed by using next generation sequence technology to assess the genetic diversity and population structure in P. atricaudus and test for cross-species amplification in P. magnus. Both species exhibited high genetic diversity (P. atricaudus: Na: 9.000 - 9.769 alleles/locus, Ho: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alleles/locus, Ho: 0.638 - 0.683, HE: 0.747 - 0.755) compared to the mean levels of genetic diversity reported for Neotropical Siluriformes, and lack of genetic differentiation among sampling sites within the Cauca River (P. atricaudus: F'ST=0.013 - 0.017, P > 0.05, D'est= -0.004 - 0.023, P > 0.05; P. magnus: F'ST= 0.031, P= 0.055; D'est= 0.045, P= 0.058). This work is the first insight on the diversity and the population genetics of species of the family Pseudopimelodidae and provides a framework to further population genetic and conservation analyses needed in this poorly studied family at the microevolutionary level.(AU)

Los bagres neotropicales Pseudopimelodus atricaudus y Pseudopimelodus magnus son dos especies recientemente descubiertas, endémicas de la cuenca Magdalena-Cauca en Colombia. En este estudio, se desarrollaron 13 loci microsatélites usando tecnología de secuenciación de próxima generación para evaluar la diversidad genética y la estructura poblacional de P. atricaudus y evaluar su amplificación cruzada en P. magnus. Ambas especies exhibieron altos valores de diversidad genética (P. atricaudus: Na: 9.000 - 9.769 alelos/locus, HO: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alelos/locus, HO: 0.638 - 0.683, HE: 0.747 - 0.755) comparados con los valores promedios de diversidad genética reportados para Siluriformes neotropicales, y ausencia de estructura genética entre los sitios analizados (P. atricaudus: F'ST= 0.013 - 0.017, P > 0.05, D'est= -0.004 - 0.023, P > 0.05; P. magnus: F'ST= 0.031, P= 0.055; D'est= 0.045, P= 0.058). Este trabajo representa la primera aproximación a la diversidad y genética poblacional de especies de la familia Pseudopimelodidae y proporciona un marco de referencia para futuros estudios genético-poblacionales y de conservación, requeridos en esta familia de bagres poco estudiada en el nivel microevolutivo.(AU)

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We present a review of Scatimus Erichson (Coleoptera: Scarabaeidae: Scarabaeinae: Ateuchini: Scatimina) in Colombia, with the description of S. strenua new species from the Central Andes (Antioquia Department). Records of S. strandi Balthasar from southwestern Colombia (Caquetá and Nariño Departments) are validated. The distributions of S. ovatus Harold from the Magdalena, Chocó-Darién, and Sierra Nevada de Santa Marta provinces and S. fernandezi Martínez in the eastern foothills of the Eastern Cordillera (Orinoco-Amazon) are confirmed. New departmental records and distribution maps for Colombia are presented; an updated key for the taxonomic identification of Scatimus is included. With a total of four species, Colombia has the second highest Scatimus species richness of any country.

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Gigagryllus omayrae n. gen et n. sp., a new genus of giant field cricket, from the middle Magdalena of Colombia, more precisely from the department of Tolima, in the region of the Armero tragedy, for which this species is dedicated to the memory of Omayra Sanchez, a symbol of the most terrible natural tragedy that has occurred in the recent history of Colombia. Gigagryllus n. gen. is one of the largest genera in America, with a size similar to Titanogryllus, Megalogryllus and some species of Gryllita. The classification of the American Gryllinae is discussed, and a key to the American genera is provided. Besides, genera groups are proposed for the subtribe Brachytrupine (Gryllini) taxa, which differs from Old World genera. Geogryllus n. syn. and Rubrogryllus n. syn. are synonymized under Gryllita and Cophogryllus americanus is considered as nomen dubium, ruling out the presence of subtribe Cophogryllina in America.

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Floods are one of the worst natural disasters in the world. Colombia is a country that has been greatly affected by this disaster. For example, in the years 2010 and 2011 there was a heavy rainy season, which caused floods that affected at least two million people and there were economic losses of 6.5 million dollars, which is equivalent to 5.7% of the country's Gross Domestic Product (GDP) at that time. The Magdalena River is the most important since 128 municipalities and 43 cities with a population of 6.3 million people, which is 13% of the total population of the country, are located in its basins. For this reason, the objective of the research is to design and implement a model that helps predict flooding over the Magdalena River by examining three techniques of artificial intelligence (Artificial Neuronal Networks, Adaptive Neuro Fuzzy Inference System, Support Vector Machine), and thus determining which of these techniques are the most effective according to the case study. The research was limited only to these three types, due to limitations of time, data, human and financial resources, and technological infrastructure. In the end, it is concluded that the Artificial Neural Networks technique is a suitable option to implement the predictive system as long as it is not very complex and does not require high processing machine. However, to establish a model based on rules to achieve a better interpretability of the floods, the ANFIS model can be used.

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Cichlids constitute a diverse monophyletic group that have developed adaptive strategies to thrive in diverse environments. Andinoacara represents an example of diversification on the South American Andean uplift, providing a key model for understanding the evolution of biogeographic patterns. In this study, we analyzed the species Andinoacara latifrons using two mitochondrial markers (COI, cytb) and one nuclear marker (RAG1) in a populational level. Sequences were obtained through tissue collection and from the GenBank database. Populational analysis showed significant structuration among populations, also corroborated with population pairwise F st results. Fu's Fs and Tajima's D results showed populations that seems to be under populational expansion. We identified 22 haplotypes using cytb. The population associations in the Cauca haplotype are related to the Momposina depression and the mixture of the Cauca-Magdalena river basins in the lower Cauca-Magdalena region. We constructed a new phylogenetic tree, which grouped mainly two A. latifrons lineages: (1) an upper Magdalena and Catatumbo clade and (2) an upper Cauca and upper Magdalena clade. Thus, A. latifrons represents a diverse entity that contributes to our understanding of the evolutionary history of northern South America. Our findings provide insight into devising public policies in determining refuges for the preservation of biodiversity in the lower Cauca and Magdalena regions in Colombia.

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Aluminum sulfate is one of the most used chemical coagulants in the world, but research has shown that high concentrations of aluminum in the body are associated with neuropathological conditions. Because of this, different alternatives have been evaluated such as natural coagulants, which are considered safe for human health and contain fewer contaminants than chemicals due to their biodegradation properties. The main objective of this study was to evaluate the efficiency of mixing nopal mucilage and cassava starch for turbidity removal in water purification. In this paper, test jars and the treatment equipment (TA-scale FQ-005/PE manufactured by Generatoris SA de CV of Mexico) was applied in order to measure turbidity and pH parameters before and after the process of coagulation-flocculation, which was applied to water from the Magdalena River in Colombia. Samples from two sampling periods were assessed. One was evaluated during the rainy season and the other was evaluated without precipitation (drought) with initial turbidities of 316 NTU and 80 NTU, respectively. It was found that aluminum sulfate as a coagulant reference obtained better turbidity removal results (up to 99%) as compared to nopal (up to 60.4%), and nopal-starch combination of cassava (up to 67%), indicating that this mixture increases the effectiveness of natural coagulants used individually. Our results indicate that this should be considered as an alternative in the water purification process.

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Prochilodus magdalenae es una especie de pez endémico de Colombia conocido por ser un importante recurso de interés comercial y para muchas comunidades relacionadas a las actividades pesqueras como actividad de sustento. No obstante, se ha observado un deterioro poblacional en ambientes naturales debido a factores tales como sobrepesca, fragmentación de ecosistemas, entre otros. Esto hace necesario caracterizar la diversidad genética de P. magdalenae en los sistemas reproductores de algunos centros piscícolas, que son usados para hacer repoblamientos en otras cuencas de Colombia y así proponer criterios técnicos y científicos que permitan el desarrollo de estrategias de manejo para la conservación de esta especie. Por lo anterior, en el año 2013 se recolectó tejido de aleta caudal de 1044 individuos en siete centros piscícolas, que fueron procesados en laboratorio y a través del uso de siete loci de microsatélites se evaluaron métricas genéticas tales como: heterocigosidad observada y esperada, número de alelos, índices de fijación, estadísticos F, agrupamiento bayesiano y AMOVA. Se encontró baja heterocigosidad observada, correlacionada con procesos de endogamia, que contrastan con los altos valores obtenidos en el índice de heterocigosidad esperada y la cantidad de alelos detectados en los sistemas de reproductores de P. magdalenae. Se detectó una moderada diferenciación genética entre centros piscícolas y se observó la existencia de tres grupos genéticos a través del agrupamiento bayesiano. Pese a la baja diversidad reportada con respecto a otras especies del mismo género, las poblaciones mantenidas en cautiverio de Bocachico tienen potencial para restaurar la diversidad de las poblaciones silvestres. Por lo que se sugiere que cada estación piscícola debe establecer lotes de reproductores por separado, en función de su información genética para que exista una congruencia entre los individuos liberados y aquellos que habitan en el medio natural.

Prochilodus magdalenae is an endemic fish species of Colombia known as an important resource of commercial interest for many communities related to fishing activities as a livelihood activity. However, population deterioration has been observed in natural environments due to factors such as overfishing, fragmentation of ecosystems, among others. This makes it necessary to characterize the genetic diversity of P. magdalenae in the productive systems of some fish farms, which are used to restocking in other basins of Colombia and, thus, to propose technical and scientific criteria that allow the development of management strategies for the conservation of this species. Therefore, in 2013, caudal fin tissue was collected from 1044 individuals in seven fish farms, which were processed in the laboratory. Through the use of seven microsatellites, genetic metrics such as: observed and expected heterozygosity, number of alleles, fixation indexes, F statistics, Bayesian grouping and AMOVA were evaluated. We observed low heterozygosity, correlated with inbreeding processes, which contrast with the high values obtained in the expected heterozygosity index and the number of alleles detected in P. magdalenae productive systems. A moderate genetic differentiation between fish centers was detected and the existence of three genetic groups was observed through the Bayesian analysis. Despite the low diversity reported regarding the others species of the same genus, populations held in Bocachico captivity have the potential to restore the diversity of wild populations. Therefore, it is suggested that each fish station should establish batches of breeders separately, based on their genetic information so that there is congruence between the released individuals and those that inhabit the natural environment.