Efecto del pulso de inundación sobre el ensamble de ostrácodos (Ostracoda: Podocopida) en microambientes en la Ciénaga Río Viejo, Colombia / Effect of the flood pulse on the ostracod assemblage (Ostracoda: Podocopida) in microenvironments in the Ciénaga Río Viejo, Colombia

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.

Spatial and temporal changes of dissolved oxygen in waters of the Pajarales complex, Ciénaga Grande de Santa Marta: Two decades of monitoring.

Ciénaga Grande de Santa Marta lagoon complex, located in the Colombian Caribbean, is a highly degraded estuarine system, in which massive deaths of organisms have occurred since the 1990s, causing socioeconomic effects on the inhabitants, who are mostly artisanal fishermen. These deaths have been attributed to the deoxygenation of the water at night, as a result of the eutrophication of the system. To understand the variability of dissolved oxygen and its relationship with other water quality variables, the monthly time series collected between 2001 and 2019, in seven stations of the Pajarales Complex (western side of the estuarine complex), were analyzed. Analyzes showed that there are significant differences between stations, as well as between the surface and the bottom of the water, indicating that the behavior of oxygen in the system is not homogeneous, a product of the hydrodynamics of the system. Also, temporal differences were found related to the periods of rain and drought, even with larger-scale climatic events such as El Niño and La Niña, with the lowest concentrations being recorded during the rainy seasons. On the other hand, the analysis of the time series of the average surface temperature of the seven stations analyzed showed a slight tendency to increase over time. Results indicate that the system is very dynamic and its oxygenation conditions are determined by climatic factors that promote changes in water chemistry, such as variations in salinity, temperature, and pH, and biological activity, determined by the abundance of the organisms. Analysis of this information becomes a tool to propose an alert system that allows reducing the impact of deaths.

Evaluation of low-cost alternatives for water purification in the stilt house villages of Santa Marta's Ciénaga Grande.

Water purification is indispensable to guarantee safe human consumption and to prevent diseases caused by the ingestion of contaminated water. This requires a series of water treatment processes which require investment. However, the economic limitations of rural communities hinder their ability to implement such water-treatment systems, as is the case in Ciénaga Grande of Santa Marta ("Large Swamp", in English) in Colombia. Low-cost systems can be used instead as simple and safe alternatives. Therefore, the objective of this work was to evaluate non-conventional, low-cost water processes to purify the water from the collection point of two stilt house villages in Ciénaga Grande of Santa Marta. These include: 1) Using two natural coagulants, Moringa Oleifera and Cassia Fistula; 2) filtration through a biosand filter and a carbon activated filter; and 3) disinfection through UV-C Radiation and through solar disinfection. The results showed a turbidity values reduction between 52% and 96% using the two natural coagulants; both turbidity and total coliforms achieved reductions of 98.4% and 76.9%, respectively in the filtration process; and removal of total coliforms up to 98.8% in the disinfection process. Despite the high rates of reduction in the different parameters, the water does not comply with the recommended limits for safe drinking water.

Habitat-dependent occupancy and movement in a migrant songbird highlights the importance of mangroves and forested lagoons in Panama and Colombia.

Climate change is predicted to impact tropical mangrove forests due to decreased rainfall, sea-level rise, and increased seasonality of flooding. Such changes are likely to influence habitat quality for migratory songbirds occupying mangrove wetlands during the tropical dry season. Overwintering habitat quality is known to be associated with fitness in migratory songbirds, yet studies have focused primarily on territorial species. Little is known about the ecology of nonterritorial species that may display more complex movement patterns within and among habitats of differing quality. In this study, we assess within-season survival and movement at two spatio-temporal scales of a nonterritorial overwintering bird, the prothonotary warbler (Protonotaria citrea), that depends on mangroves and tropical lowland forests. Specifically, we (a) estimated within-patch survival and persistence over a six-week period using radio-tagged birds in central Panama and (b) modeled abundance and occupancy dynamics at survey points throughout eastern Panama and northern Colombia as the dry season progressed. We found that site persistence was highest in mangroves; however, the probability of survival did not differ among habitats. The probability of warbler occupancy increased with canopy cover, and wet habitats were least likely to experience local extinction as the dry season progressed. We also found that warbler abundance is highest in forests with the tallest canopies. This study is one of the first to demonstrate habitat-dependent occupancy and movement in a nonterritorial overwintering migrant songbird, and our findings highlight the need to conserve intact, mature mangrove, and lowland forests.

Captura y selectividad del zooplancton por Utricularia foliosa (Lentibulariaceae) en la Ciénaga de Paredes, Santander, Colombia / Capture and selectivity of zooplankton by Utricularia foliosa (Lentibulariaceae) in the Ciénaga de Paredes, Santander, Colombia

ResumenLas plantas carnívoras del género Utricularia, capturan un amplio ámbito de organismos acuáticos. La mayoría se desarrollan en ambientes con carencias de nutrientes y tienen la capacidad de cambiar las condiciones de su microambiente. El objetivo de la presente investigación fue estudiar la selectividad, en la captura de zooplancton por Utricularia foliosa en la Ciénaga de Paredes; entre febrero y noviembre 2014. Se determinó si existe selección en los recursos alimentarios de la planta con el índice de Czekanowski y el grado de selección, a través de los índices de Savage e Ivlev. Se estableció la relación existente entre los patrones de captura y selección del zooplancton, con variables físicoquímicas y la disponibilidad de nutrientes en la Ciénaga. En nuestros resultados, el índice de Czekanowski evidenció selección, en los recursos alimentarios de la planta, durante todo el pulso de inundación, con valores entre 0.28 y 0.41. Se encontró selección positiva significativa, con el índice de Savage, para los géneros Lecane sp., Alona sp., Ceriodaphnia sp., y Bosmina sp. (p < 0.05). Se obtuvieron resultados similares, con el índice de Ivlev. La intensidad en la selección de los géneros varió entre periodos hidrológicos y por periodos de aguas altas y bajas. Se identificó que los cambios en la concentración de amoniaco y nitrato, además de la variación en la conductividad eléctrica de la ciénaga influencian la captura que realiza U. foliosa. Este es el primer trabajo que permite dar un acercamiento al entendimiento de la selección de recursos alimentarios dentro de la especie a través de índices de selectividad y uno de los pocos para el género.

Abstract:Utricularia is a genus of carnivorous plants that capture a wide range of aquatic organisms. Most of these plants grow in environments with nutrients deficiency and have the ability to change the conditions of their microenvironment. The aim of this research was to study the selectivity in the zooplankton capture by Utricularia foliosa in the Ciénaga de Paredes. Our study was undertaken between February and November, 2014. We tried to determine if there is selection in the plant's food resources by the Czekanowski's index, and the selection degree by the Savage and Ivlev's indexes. Additionally, we studied the possible relation between the patterns of zooplankton capture and selection, with physicochemical variables in the swamp. The Czekanowski's index showed a food selection in plant resources throughout the flood pulse, with values between 0.28 and 0.41. We also found a significant positive selection with Savage's index for Lecane sp., Alona sp., Ceriodaphnia sp., and Bosmina sp. (p < 0.05); similar results were obtained with Ivlev's index. The intensity in the selection of each captured genus varied significantly between hydrological periods and between high and low water levels in the swamp. It was possible to identify some changes in the ammonia and nitrate concentration and some variability in the electric conductivity of the swamp, which influenced the captures made by U. foliosa. This is the first paper that allows an approach to understand the selection of food resources for the species, using a selectivity index, and one of the few for the genus. Rev. Biol. Trop. 64 (3): 1297-1310. Epub 2016 September 01.

Genetic diversity detection of the domestic horse (Equus caballus) by genes associated with coat color / Detección de la diversidad genética del caballo doméstico (Equus caballus) mediante genes asociados al color del pelaje

Objective. To assess the population structure and genetic diversity in populations of domestic horse (Equus caballus) in the municipality Cienaga de Oro-Córdoba (Colombia). Materials and methods. Random sampling were conducted between August and October 2013, in adult animals on farms seven districts, which was carried out phenotypic characterization of each animal, based on autosomal markers encoding morphological Extension (E) , Agouti (A), Cream (C), White (W), Gray (G), Tobiano (TO), Overo (O) and Roan (RN). Population genetic parameters: allele frequency, genetic diversity, gene flow, Hardy-Weinberg equilibrium and genetic distance were calculated through the program POPGENE 1.31; the genetic structure was assessed using the program FSTAT v. 2.9.3.2. Results. 341 individuals were analyzed in the seven populations studied, where the Extension gene Was the MOST faq frequently as the Overo and Tobiano genes showed the lowest values. Insignificant values of genetic variability and population recorded a global level, likewise, low genetic differentiation among populations, accompanied by a high gene flow was obtained; an excess of heterozygotes at population and global level was observed; to this is added the presence of Hardy-Weinberg equilibrium in all populations relative to the markers studied and low genetic distance values ​​were reported. Conclusions. The populations are highly genetically related, a situation that may result from the existing geographical proximity between them, favoring genetic exchange and the establishment of a metapopulation.

Objetivo. Evaluar la estructura poblacional y la diversidad genética en poblaciones de caballo doméstico (Equus caballus), en el municipio Ciénaga de Oro, Córdoba (Colombia). Materiales y métodos. Se realizaron muestreos aleatorios entre los meses de Agosto y Octubre del año 2013, en animales adultos presentes en las fincas de siete corregimientos, donde se llevó a cabo la caracterización fenotípica a cada animal, atendiendo a los marcadores autosómicos de codificación morfológica Extension (E), Agouti (A), Cream (C), White (W), Gris (G), Tobiano (TO), Overo (O) y Roan (RN). Los parámetros genéticos poblacionales: frecuencia alélica, diversidad genética, flujo génico, equilibrio Hardy-Weinberg y distancia génica, fueron calculados a través del programa PopGene 1.31; la estructura genética se evaluó mediante el programa FSTAT v. 2.9.3.2. Resultados. Se analizaron 341 individuos en las siete poblaciones estudiadas, donde El marcador Extensión fue el de mayor frecuencia mientras los genes Overo y Tobiano presentaron los menores valores. Se registraron cifras poco significativas de variabilidad genética a nivel global y poblacional, así mismo, se obtuvo una escasa diferenciación genética entre las poblaciones, acompañado de un elevado flujo génico; se observó un exceso de heterocigotos a nivel poblacional y a nivel total, a esto se le suma la presencia de equilibrio Hardy-Weinberg en todas las poblaciones con relación a los marcadores estudiados y se reportaron valores bajos de distancia genética. Conclusiones. Las poblaciones se encuentran muy relacionadas genéticamente, situación que puede obedecer a la cercanía geográfica existente entre ellas, favoreciendo el intercambio genético y la constitución de una metapoblación.

Efecto antimicrobiano de hojas de Melaleuca leucadendron L, que crece en la Ciénaga de Zapata / Antimicrobial effect of the leaves of Melaleuca leucadendron L growing in Cienaga de Zapata

SUMARY Melaleuca leucadendron L is a tree commonly known as cayeput, being an invasive, undesirable species in Cienaga de Zapata, in the province of Matanzas. According to the referred usages, it might be exploited in a reasonable way as an antimicrobial agent. As our objective we pretended to determine antimicrobial activity in the fluid extract of the leaves of this tree wildly growing in the before mentioned territory. The extract was obtained by repercolation and the assay was carried out in vitro, using the methods of diffusion in agar and dilution in a liquid media. Different concentrations of the extract were used against bacteria, yeast, and filamentous fungi. The microbicidal effect of the extract was demonstrated for all the tested microorganisms, establishing values of minimal inhibitory, minimal bactericidal and minimal fungicidal effects of the concentration. The effect kept steady during four years. These results confirm the purpose of using as antimicrobial the raw vegetable material existing in excess in the region. It is recommended to take into account the matters discussed in the study according to the undesirable effects, so other studies are required to deepen in that sense. The evaluation risk-benefit should be observed to use the tree in the medical practice with the precautions also demanded by other well-known antimicrobials.

Cambios nictemerales de variables físicas y químicas en la Ciénaga de Paticos, complejo cenagoso de Ayapel, Colombia

Nictemeral variation of physical and chemical variables in the Paticos wetland, Ayapel swamp complex, Colombia. The nictemeral variation of abiotic factors in a key factor for tropical organisms. We evaluated some climatic, physical and chemical variables during four surveys of the hydrologic cycle in the Paticos wetland (8º21’08.2" N, 75º08’45.7" W). Of climatic variables, pluviosity presented the highest variation (C.v. = 1 022 %) followed by air temperature (C.V. = 19.7%). There was a high relation in the coefficients of variation for these variables (84:1). This relation may be associated with altitude. Throughout the day-night cycle, most variables presented significant differences; except for pluviosity, air and water temperature (because of their high variability). variables most related with nictemeral variation were pluviosity, wind speed and direction, air temperature and dissolved oxygen. Rev. Biol. Trop. 57 (3): 635-646. Epub 2009 September 30.

Se evaluó la variación nictemeral de algunas variables climáticas, físicas y químicas durante cuatro muestreos dentro del ciclo hidrológico en la Ciénaga de Paticos (8º21’08.2" N, 75º08’45.7" W). Entre las variables climáticas, la pluviosidad presentó la mayor variación (C.V. = 1 022 %) seguida por la temperatura del aire (C.V. = 19.7 %). La elevada relación entre los coeficientes de variación de estas variables (84:1) está asociada a un incremento de esta relación con la disminución de la altura en la zona tropical. A través del ciclo día-noche la mayoría de las variables presentaron diferencias estadísticas significativas (excepto la pluviosidad, la temperatura del aire y del agua, lo cual se debe a su elevada variación). El análisis de correlación mostró que las variables más relacionadas con la variación nictemeral fueron la pluviosidad, la velocidad y dirección del viento, la temperatura del aire y del agua, el pH y la concentración de oxígeno disuelto.