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Los ríos de flujo libre (RFL) se caracterizan por su conectividad fluvial íntegra y por proveer múltiples beneficios a las comunidades asentadas en ellos. Sin embargo, a nivel mundial estos tipos de ríos se encuentran amenazados por la construcción de obras de infraestructura. En ocasiones, la pluralidad de valores que las comunidades le atribuyen a estos ríos no se toma en cuenta, particularmente al momento de planificar proyectos de desarrollo, lo que podría detonar conflictos ambientales. Se analizaron los valores sociales asociados con el río Los Horcones (RLH) entre dos localidades, río arriba (Las Juntas y Los Veranos) y río abajo (Boca de Tomatlán). A partir del análisis de 35 entrevistas y el uso redes semánticas, se encontró que ambas comunidades tienen un interés común por la protección y conservación del río Los Horcones. Sin embargo, se observa una ponderación diferencial de valores específicos por localidad. Río abajo (Boca de Tomatlán) predominan los valores intrínsecos y relacionales, dado que el RLH es fundamental para la diversificación de sus medios de vida. En contraste, río arriba (Las Juntas y Los Veranos) predominan los valores relacionales e instrumentales debido a la dependencia económica del turismo de naturaleza que se realiza en el RLH. El reconocimiento de la pluralidad de valores asociados con los ríos de flujo libre es esencial para la formulación de estrategias de manejo y conservación de los recursos hídricos.

Biodiversity is confronted globally by multiple stressors. Environmental policies must regulate these stressors to achieve targets, but how should that be done when the outcomes of limits on one stressor are contingent on other stressors, about which there is imperfect knowledge? Deriving regulatory frameworks that incorporate these contingencies is an emerging challenge at the science–policy interface. To be fit for implementation, these frameworks need to facilitate the inherently sociopolitical process of policy implementation and account transparently for uncertainty, such that practitioners and other stakeholders can more realistically anticipate the range of potential outcomes to policy. We developed an approach to quantify stressor limits that explicitly accounts for multistressor contingencies. Using an invertebrate data set collected over 30 years throughout New Zealand, we combined ecological and ecotoxicological models to predict biodiversity loss as a function of one stressor, treating multistressor contingencies as a form of uncertainty about the outcomes of limits on that stressor. We transparently accounted for that uncertainty by presenting regulatory limits as bands bounded between optimistic and pessimistic views that practitioners may have about the local context within which limits are applied. In addition to transparently accounting for uncertainties, our framework also leaves room for practitioners to build stakeholder consensus when refining limits to suit different local contexts. A criticism of this open, transparent approach is that it creates too much scope for choosing limits that are lenient on polluters, paralyzing on‐the‐ground management of multiple stressors, but we demonstrate that this is not necessarily the case. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Freshwater ecosystems and their bordering wetlands and riparian zones are vital for human society and biological diversity. Yet, they are among the most degraded ecosystems, where sharp declines in biodiversity are driven by human activities, such as hydropower development, agriculture, forestry, and fisheries. Because freshwater ecosystems are characterized by strongly reciprocal linkages with surrounding landscapes, human activities that encroach on or degrade riparian zones ultimately lead to declines in freshwater–riparian ecosystem functioning. We synthesized results of a symposium on freshwater, riparian, and wetland processes and interactions and analyzed some of the major problems associated with improving freshwater and riparian research and management. Three distinct barriers are the lack of involvement of local people in conservation research and management, absence of adequate measurement of biodiversity in freshwater and riparian ecosystems, and separate legislation and policy on riparian and freshwater management. Based on our findings, we argue that freshwater and riparian research and conservation efforts should be integrated more explicitly. Best practices for overcoming the 3 major barriers to improved conservation include more and sustainable use of traditional and other forms of local ecological knowledge, choosing appropriate metrics for ecological research and monitoring of restoration efforts, and mirroring the close links between riparian and freshwater ecosystems in legislation and policy. Integrating these 3 angles in conservation science and practice will provide substantial benefits in addressing the freshwater biodiversity crisis. [ABSTRACT FROM AUTHOR]

In this brief, non-exhaustive essay, we review major adaptive changes in reproductive and developmental traits of decapod crustaceans, which have passed through evolutionary transitions from ancestral life in coastal marine environments to brackish, limnic, polar, or deep-sea habitats. Two major approaches can be recognised in studies of life-history evolution, focussing on: (1) developmental changes in adaptive physiological or biochemical traits of successive ontogenetic stages, comparing, for instance, osmoregulatory capabilities in larvae, juveniles, and adults ("ontogeny of adaptations" perspective); (2) adaptive changes in the modes of reproduction and development, e.g., enhanced maternal energy investment in egg production, abbreviated, non-feeding larval development ("adaptations in ontogeny"). Using both scientific approaches, Christoph D. Schubart has significantly contributed to our understanding of evolutionary transitions in crustaceans. In our essay, we pay particular attention to the significance of nutritional selection factors in relation to presumably adaptive developmental, physiological, and biochemical traits in different life-history stages. In this context, we highlight the key roles of lipids and carotenoid pigments, in particular of essential polyunsaturated fatty acids (PUFAs) and astaxanthin. While PUFAs and other lipid compounds have received wide scientific attention, we propose that future studies should further analyse also the potential role of astaxanthin and other essential carotenoids. [ABSTRACT FROM AUTHOR]

Despite their ecological importance, research on symbionts of amphipods has been limited in South America. The present study provides a comprehensive overview of symbiont organisms in the freshwater amphipods of the genus Hyalella in South America. Our findings reveal various taxa such as Apicomplexa, Microspora, Peritrichia, Folliculinidae, trematodes, nematodes, cestodes and acanthocephalans, often involving complex life cycles. Studies on symbionts have been done almost exclusively in Argentinean Patagonia. The present overview allows us to know the species that use amphipods, to elucidate their lifecycles and to know their occurrence values. [ABSTRACT FROM AUTHOR]

Este trabajo presenta el estado del conocimiento de los coleópteros acuáticos de Colombia, con énfasis en los listados de especies de 17 familias registradas en el territorio colombiano, los cuales han sido provistos por el Grupo Coleoptera de Colombia y publicados por el SiB-Colombia. Se aporta información actualizada de riqueza, diagnosis, hábitat y distribución geográfica de todas las familias de coleópteros acuáticos presentes en Colombia. Se registraron 241 especies en 112 géneros, los cuales son considerados como coleópteros acuáticos verdaderos, falsos o riparios según su asociación con los cuerpos de agua.

El objetivo de este trabajo es proporcionar un nuevo registro de ocurrencia de las almejas asiáticas Corbicula fluminea y Corbicula largillierti en el río Jacarecica, nordeste de Brasil. También se proporcionan datos sobre la abundancia y las clases de tamaño de ambas especies. Estos resultados contribuyen a una evaluación más completa de la distribución de las especies en la región nordeste de Brasil.

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Del total del agua del planeta, sólo 0,4% está disponible como agua potencialmente útil como suministro de agua potable. Estas cifras determinan el carácter escaso y preciado del agua; lo cual se agrava al tomar en cuenta el sustancial incremento de los procesos de contaminación de las principales fuentes disponibles dada la acción antrópica, principalmente los últimos cien años. En este sentido, el propósito subyacente gira en torno a una contextualización integral de los factores promotores del proceso de degradación de los ecosistemas donde se asientan las cuencas hídricas y dentro de los cuales, es la reforestación, una de las herramientas dirigidas a superar los daños causados al entorno. A fin de alcanzar el propósito trazado, el esquema metódico aplicado se centró en un estudio de tipo documental; básicamente enfocado en recopilar información a partir de diversas bases de datos reconocidas. Los principales hallazgos del estudio resaltan la marcada separación de los ecosistemas naturales y los ecosistemas sociales, bajo un enfoque de carácter normativo a través del cual se fortalece una visión sectorial y se refuerzan, por tanto, los pilares culturales de donde procede. Se rompe así, la mirada de continuidad entre ecosistema (cuenca hídrica) y sociedad. Finalmente, el actual modelo económico, caracterizado por la lógica del capital y centrado en la rápida obtención de beneficios, aunado a un acelerado crecimiento de la población a nivel mundial, ha impulsado importantes desequilibrios desde diferentes ámbitos del acontecer diario de la humanidad.

The aquatic beetles of the Elmidae family are widely used in the hydrobiological monitoring of lotic ecosystems. In this work, samples belonging to 22 municipalities and 38 bodies of water in the department of Antioquia were reviewed, which were collected using a triangular or surber network. The species Cylloepus francescae, C. whitemanae, Macrelmis clypeata, M. elicioi and Disersus longipennis are recorded for the first time in Colombia. This information contributes to the updating of the number of species and geographical distribution of the family Elmidae in Colombia. [ABSTRACT FROM AUTHOR]

Último estadio larvario de Neocordulia volxemi (Selys, 1874) (Odonata, Libelluloidea) del sureste del Brasil. Neocordulia es un género neotropical que comprende 16 especies distribuidas en América del Sur y América Central. Hasta la fecha, solo se han descrito siete larvas de este género. En este artículo describimos el último estadio larvario de Neocordulia volxemi (Selys, 1874), recogida en la zona de protección ambiental de la cuenca del río Uberaba en el estado de Minas Gerais, en el Brasil. Se encontraron adultos de color verde metálico volando en una zona forestal de una unidad de conservación, mientras que la larva se encontró en una cascada rodeada de paredes rocosas. La zona, que es un vestigio de Cerrado, se encuentra actualmente amenazada por pastos degradados y el aumento de los monocultivos.

The postmortem diagnosis of death by drowning is one of the most difficult issues in forensic pathology. We investigated possible evidence differentiating saltwater drowning from freshwater drowning by histopathological changes in brain, heart, lungs, liver, and kidneys tissues. A cross section descriptive study was carried out on eighteen 12-week-old male Wistar rats; they were divided equally into 3 groups. Group 1: control group; Group 2: death by drowning in freshwater; Group 3: death by drowning in saltwater. Immediately after death, all tested organs were removed and fixed for histopathological examination. The brain of freshwater group depicted degenerated neurocytes with dystrophic changes in the form of shrunken cell, pyknotic nuclei and deeply eosinophilic cytoplasm. The heart showed clear evidence of myocyte injuries in saltwater drowning compared to the control and freshwater groups. The kidneys of rats drown in saltwater revealed more glomerular destruction with no differences in tubulo-interstitial changes in comparison with those drown in freshwater. In the lungs, the changes in freshwater were restricted to the alveoli, and the bronchial changes were more distinctive in saltwater. No disturbed liver architecture was seen in both test groups, however hydropic degeneration, congested vessels, and sinusoids were more distinct in saltwater group. In conclusion, diagnostic differentiation between fresh and saltwater drowning was reliable in rats' lungs and heart with minimal differentiation in liver, kidneys, and brain. Further studies of drowning with different staining techniques will help to clarify the potential role of histopathological changes in body organs as indicator of drowning. [ABSTRACT FROM AUTHOR]

A central tenet of landscape ecology is that mobile species depend on complementary habitats, which are insufficient in isolation, but combine to support animals through the full annual cycle. However, incorporating the dynamic needs of mobile species into conservation strategies remains a challenge, particularly in the context of climate adaptation planning. For cold‐water fishes, it is widely assumed that maximum temperatures are limiting and that summer data alone can predict refugia and population persistence. We tested these assumptions in populations of redband rainbow trout (Oncorhynchus mykiss newberrii) in an arid basin, where the dominance of hot, hyperproductive water in summer emulates threats of climate change predicted for cold‐water fish in other basins. We used telemetry to reveal seasonal patterns of movement and habitat use. Then, we compared contributions of hot and cool water to growth with empirical indicators of diet and condition (gut contents, weight–length ratios, electric phase angle, and stable isotope signatures) and a bioenergetics model. During summer, trout occurred only in cool tributaries or springs (<20 °C) and avoided Upper Klamath Lake (>25 °C). During spring and fall, ≥65% of trout migrated to the lake (5–50 km) to forage. Spring and fall growth (mean [SD] 0.58% per day [0.80%] and 0.34 per day [0.55%], respectively) compensated for a net loss of energy in cool summer refuges (–0.56% per day [0.55%]). In winter, ≥90% of trout returned to tributaries (25–150 km) to spawn. Thus, although perennially cool tributaries supported thermal refuge and spawning, foraging opportunities in the seasonally hot lake ultimately fueled these behaviors. Current approaches to climate adaptation would prioritize the tributaries for conservation but would devalue critical foraging habitat because the lake is unsuitable and unoccupied during summer. Our results empirically demonstrate that warm water can fuel cold‐water fisheries and challenge the common practice of identifying refugia based only on summer conditions. Article impact statement: Warm downstream habitats may be critical for cold‐water fisheries but are overlooked by climate adaptation planning. [ABSTRACT FROM AUTHOR]

Benthopelagic species had a mean (SD) of 35 particles/fish (22) (median = 27 particles) compared with a mean of 62 particles/fish (110) for demersal species (median = 25 particles). Particle characteristics Fish in the Great Lakes we examined contained a broad range of particle morphologies; diversity was greatest in fish from Lake Ontario. Keywords: anthropogenic particle; freshwater; Great Lake; ingestion; microplastics; plastics; agua dulce; Grandes Lagos; ingesta; microplásticos; partícula antropogénica; plásticos EN anthropogenic particle freshwater Great Lake ingestion microplastics plastics agua dulce Grandes Lagos ingesta microplásticos partícula antropogénica plásticos 1 11 11 03/02/22 20220201 NES 220201 INTRODUCTION Microplastics (MPs) have been observed in all ecosystems (Koelmans et al., 2019; Law, 2017; Wang et al., 2019), and contamination in fish, an indicator of ecosystem functioning (Foley et al., 2018; Wang et al., 2020; Wright et al., 2013), is widespread. The highest mean was 59 particles/fish (SD 104) (median = 26) in Lake Ontario, and the maximum abundance of anthropogenic particles in bony fish globally is 915 particles/fish. [Extracted from the article]

The continental aquatic systems constitute environments of relevance for the human being due to the different benefits and services that they provide to society. The introduction of exotic species constitutes a threat to native fauna due to competition for food resources, excessive predation or genetic alterations. The Asian clam Corbicula fluminea has spread throughout the Americas, Africa and Europe, encompassing a great diversity of freshwater ecosystems. This species has various associated problems and its report is essential since it provides useful information to the authorities to develop management strategies that allow evaluating and mitigating the impact on the populations of native aquatic organisms. [ABSTRACT FROM AUTHOR]

Bird populations are limited by internal factors such as immigration and migration as well as external factors such as competing for food with other species. The Snail-Kite (Rostrhamus sociabilis) and the Limpkin (Aramus guarauna) share their habitat both of them feed almost exclusively in Apple-Snails (Pomacea). In this document we report on the distribution and abundance of both species, as well as their preferred size of prey at Laguna Bacalar in Quintana Roo, Mexico. From June 2012 to August 2013 we conducted 10 field expeditions and surveyed 36 transects of 500 m each. Snail-Kites and Limpkins were always present in Laguna Bacalar. We observed 319 Snail-Kites; 181 adults, 87 juvenile and 66 indeterminate sex birds. Of the adults 67% were males and 33% female. Their monthly average abundance was 63.3 ± 46.2 individuals. As for the Limpkins, 339 were recorded; their monthly average abundance was 73.3 ± 82.8 individuals. We found evidence of prey selection by size compared with the snails available in the lagoon. Average siphonal length (LS) of snails consumed was 37 ± 0.56 mm. (n= 4312). The smallest LS depredated was 17 mm and the largest of 55 mm. Of snails available in the environment, the average LS was 33 ± 2.82 mm. We recommend further research be conducted on diet and reproductive ecology of both species and on the human consumption of snails in order to provide advice for their management and conservation.

Introduction: One of the significant threats to aquatic ecosystems is introducing non-native species in natural environments. This represents one of the principal causes of biodiversity loss in the world. Pangasianodon hypophthalmus is an introduced species in Colombia that shares life characteristics and habitat with endangered native species, such as Ageneiosus pardalis, Sorubim cuspicaudus, and Pseudoplatystoma magdaleniatum. However, its distribution is little-known, and scientists have barely explored the effects on the native fauna. Objectives: To evaluate the P. hypophthalmus invasive potential in some of the Colombian basins, which drain into the Caribbean Sea. Methods: Using records available in various databases, we performed a niche conservatism analysis between the native and introduced records of P. hypophthalmus using the R package Ecospat. Subsequently, we modeled the potential invasion area of P. hypophthalmus and the distribution areas of three native species, performing ecological niche modeling (ENM) using the Maxent algorithm. Finally, we calculated a geographic niche overlap between the non-native and native species. Results: The Ecospat spatial analysis indicated that P. hypophthalmus retains some environmental niche attributes through space. For this reason, we can use ENM as an approximation to its range of distribution in the invaded area. Our results using ENM demonstrated that the four species analyzed prefer low and slightly rocky regions; therefore, the geographical overlap of the three native species’ ecological niches and the introduced species exceed 80 %. Conclusions: There are adequate conditions in the study basins to fully establish the species P. hypophthalmus, representing a high risk for aquatic ecosystems and native ichthyofauna. Knowledge of the potential distribution areas is essential to implement control of the species. [ABSTRACT FROM AUTHOR]

Este artículo hace una revisión de literatura científica sobre la importancia comercial de los peces ornamentales (PO) en Colombia. Entre los principales resultados se encuentra que este mercado continúa siendo una actividad de intercambio mundial de especies exóticas que genera grandes ganancias y que se ha sostenido con el comercio de más de mil millones de especies cada año. La mayoría de los PO son extraídos de las poblaciones naturales y terminan su destino en acuarios distribuidos en el mundo, lo que genera agotamiento del recurso asociado a la sobrepesca y las actividades de extracción. Las prácticas de captura, manejo y las tasas elevadas de mortalidad representan un importante problema de bienestar, además de un costo económico y ambiental significativo para la industria. Suramérica sigue siendo el mayor proveedor de especies, principalmente los países biodiversos y de tradición exportadora como Colombia, donde es considerado como un recurso comercial o de subsistencia de gran importancia para las poblaciones de pescadores e indígenas. Se confirmó un listado de 522 especies de PO, agrupadas en 13 órdenes, 49 familias y 213 géneros cuyas especies más apetecidas son: Osteoglossum bicirrhosum, Osteoglossum ferreirai, Paracheirodon axelrodi, Pterophyllum altum, Panaque nigrolineatus y Callichthyidae Callichthyidae. Las problemáticas asociadas a los pocos estudios realizados en PO, la limitada legislación que regule y proteja los ecosistemas y su biodiversidad, sumado a las malas prácticas y al incentivo al cultivo, el abandono de las comunidades pesqueras que dependen de este recurso, han limitado el crecimiento del sector. Urge contemplar alternativas sostenibles que disminuyan la presión de pesca sobre las especies, que abarquen aspectos sanitarios, nutricionales y de uso eficiente del recurso agua con el fin de permitir el uso y la conservación de las especies de PO, de esta manera crecería mucho más este comercio y su contribución a la economía del país sería también mayor.

El presente estudio reporta la diversidad ictiológica de la quebrada Mayapo en base a material depositado en la Colección Ictiológica del Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos (MUSM), en los años 2005, 2009 y 2010, proveniente de 30 puntos de muestreo de la quebrada Mayapo y afluentes ubicados entre los 256 y 557 m de altitud. Se identificaron 60 especies agrupadas en 39 géneros, 16 familias y cuatro órdenes, siendo los órdenes Characiformes y Siluriformes y las familias Characidae y Loricariidae los grupos más representativos. La diversidad de especies fue moderada, en comparación a otras evaluaciones en la Amazonia peruana. La composición taxonómica siguió el patrón predominante en aguas continentales de la Región Neotropical y en la Amazonia peruana. Se registraron especies de importancia pesquera, hábitos migratorios y distribución restringida.

Se reproduce documento escrito hace prácticamente un siglo, por el profesor de la Universidad de Cartagena, Manuel Pájaro Herrera, uno de los intelectuales médicos de mayor reconocimiento en Cartagena de Indias, Colombia, en las dos primeras décadas del siglo XX. El texto es ejemplo de la magnitud de la apropiación del concepto de argumentación científica que tenía el autor. También es prueba de su preocupación académica por lo relacionado con la salubridad y la higiene. El texto prueba la existencia de la preocupación sobre la disponibilidad y la calidad del agua. Se mira la realidad local en detalle y se contrasta con la internacional, utilizando como referencia datos y cifras de ciudades europeas, mientras a la vez, hechos históricos y aconteceres propios como lejanos, son fuentes para la reflexión. El texto es un llamado a los directivos sociales, líderes de opinión ciudadana, ambientalistas y gobernantes departamentales y municipales, para un trabajo conjunto con miras a una provisión de agua teniendo en cuenta calidad y abundancia. Pese a los años que han transcurrido desde la publicación inicial, el llamado sigue siendo válido, gran parte de las preguntas que derivaban en preocupaciones para el profesor Manuel Pájaro H., aún deben ser contextualizas, tomas en consideración y es deber buscarles respuesta acertada. Rev.cienc.biomed. 2014;5(2):382-389.

Se presenta el estudio del contenido de mercurio en sedimentos marinos en nueve estaciones de muestreo del Estero Huaylá en Puerto Bolívar (Ecuador), mediante espectrofotometría de absorción atómica con nebulización de llama y con la generación de hidruros con atomización en celda de cuarzo. La evaluación del riesgo ecológico fue determinada calculando el factor de contaminación (fi) y el índice de riesgo ecológico potencial (IREP) en cada punto de muestreo. El resultado obtenido, para cada metal, fue comparado con los valores de la guía de calidad de sedimentos existentes: CEL (Concentración con efecto limite) y CEP (Concentración con efecto probable). Los resultados demuestran que la concentración de mercurio fue elevada en todas las estaciones con un mínimo de 0,89 y un máximo de 5,79 μg/g, mientras que para el plomo fueron obtenidos valores entre 0,04 y 0,09 μg/g. Con respecto al riesgo toxicológico, los valores de concentración de mercurio y plomo sobrepasaron el valor límite CEL y algunos valores de mercurio también sobrepasaron el valor de CEP indicando que el mercurio más que el plomo representa un riesgo toxicológico para la biota en los sedimentos del estero Huaylá. Con respecto al valor del factor de contaminación, todos los puntos fueron diagnosticados como altamente contaminados por mercurio, mientras que para el plomo no fueron detectadas concentraciones significativas con el método de cuantificación empleado. El índice de riesgo ecológico potencial, considerando al mercurio, reveló tres sitios muy contaminados, cinco fuertemente contaminados y uno moderadamente contaminado. En contraste, para el plomo, todos los puntos de muestreo se encuentran por debajo de los límites permitidos. Los puntos con mayor concentración de mercurio y más alto riesgo de contaminación fueron aquellos situados cerca de las empresas distribuidoras de fertilizantes y cal para camaroneras y cerca de las estaciones de gasolina. En conclusión, el estero Huaylá posee altas concentraciones de mercurio en sus sedimentos probablemente a causa de la desembocadura de aguas provenientes de la actividad minera de explotación de oro en la zona que es transferida por las corrientes intermareal desde el estero Santa Rosa al estero Huaylá. Se destaca la urgente necesidad de establecer valores de referencia en la norma ambiental ecuatoriana debido a que la misma no contempla límites de mercurio para sedimentos marinos y/o dulceacuícolas.

Introduction: Crustaceans have economic and ecological importance and the role of caridean crustaceans in lentic environments is crucial to maintain the trophic structure. The species Atya scabra is occasionally associated with fisheries, especially in Northeast and Northern Brazil. Objective: To determine the population structure, reproductive period, patterns of growth and distribution of size classes among sexes in a population of the prawn A. scabra in the De Contas River, Bahia, Brazil. Methods: Individuals were sampled in a period of one year by passing sieves through marginal vegetation and using dragnets. In the laboratory, we recorded the sex of the individuals and measured them using a pachymeter with 0.001 mm precision. The dimensions measured were CL (carapace length), TL (total length) and CW (carapace width). In order to analyze data, linear models for the relationships CL x CW were constructed and the type of allometry for each sex was determined. Individuals were grouped into size classes of 5 mm intervals. A chi-square test (χ²) was used to test deviation from the 1:1 sex ratio. The proportion of ovigerous females was registered for each month to determine the breeding period. Results: A total of 517 individuals were collected, 328 were males and 186 females of which 169 were ovigerous. Males showed a polymodal distribution in size classes and were significantly larger than females, which presented a unimodal distribution in size classes. The observed growth patterns demonstrated that both sexes present negative allometry. However, sexual dimorphism was detected when comparing the growth parameters. Ovigerous females were sampled the entire year and size-frequency data demonstrated that recruitment also occurs throughout the year, which allowed us to classify their reproduction as continuous. Conclusions: Our data is essential to draw sustainable fishery management strategies. We suggest a minimum capture size of 70 mm and capture restrictions from May to August. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Científico Centro de Museos de Historia Natural is the property of Universidad de Caldas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Protected areas are an important part of broader landscapes that are often used to preserve biodiversity or natural features. Some argue that protected areas may also help ensure provision of ecosystem services. However, the effect of protection on ecosystem services and whether protection affects the provision of ecosystem services is known only for a few services in a few types of landscapes. We sought to fill this gap by investigating the effect of watershed protection status and land use and land cover on biodiversity and the provision of ecosystem services. We compared the ecosystem services provided in and around streams in 4 watershed types: International Union for Conservation of Nature category II protected forests, unprotected forests, unprotected forests with recent timber harvesting, and unprotected areas with agriculture. We surveyed 28 streams distributed across these watershed types in Quebec, Canada, to quantify provisioning of clean water, carbon storage, recreation, wild foods, habitat quality, and terrestrial and aquatic biodiversity richness and abundance. The quantity and quality of ecosystem services and biodiversity were generally higher in sites with intact forest—whether protected or not—relative to those embedded in production landscapes with forestry or agriculture. Clean‐water provision, carbon storage, habitat quality, and tree diversity were significantly higher in and around streams surrounded by forest. Recreation, wild foods, and aquatic biodiversity did not vary among watershed types. Although some services can be provided by both protected and unprotected areas, protection status may help secure the continued supply of services sensitive to changes in land use or land cover. Our findings provide needed information about the ecosystem service and biodiversity trade‐offs and synergies that result from developing a watershed or from protecting it. Article impact statement: Streams surrounded by forest—protected or not—support more ecosystem services and biodiversity than streams in production landscapes. [ABSTRACT FROM AUTHOR]

Water pollution is a consequence of the industrialization and the society's development due to the constant pouring of domestic and industrial wastewater without a previous treatment; these facts contribute to the environment deterioration and the diversity lost. Three sampling stations of Almendares River (Havana, Cuba) with different pollution levels were studied for one year, to characterize the structure of rapid growth culturable heterotrophic bacterial community. For isolation, serial dilutions of water samples were grown in nutrient agar and incubated at 30°C for 72h. Representative different morphology colonies were isolated and purified on the same culture medium. A total of 60 isolates were obtained and were identified by API system as belonging to the genera Acinetobacter, Arthrobacter, Bacillus, Micrococcus, Staphylococcus, Alcaligenes, Citrobacter and Pseudomonas, prevailing the phyla Firmicutes, Actinobacteria and Proteobacteria. The genus Arthrobacter was isolated more frequently in the sampling station Paila, compared with the rest of the Almendares River stations, while the genera Acinetobacter and Bacillus were isolated more frequently in Río Cristal and Puente de Hierro stations. To characterize the bacterial community structure were used indexes of species richness (S*), Simpson (L') and Shannon-Wiener (H'). The indexes of Simpson and Shannon-Wiener showed significant differences among the bacterial diversity of the three sampling stations. No significant differences were detected by analyzing the species richness. The results showed the influence of pollution on bacterial diversity, which is significantly affected from upstream to downstream in Almendares River. [ABSTRACT FROM AUTHOR]

Objective: to describe clinical and epidemiological aspects of freshwater stingray injuries in the city of Belém, Pará, brazilian amazon. Method: descriptive, epidemiological and observational study, carried out between 1999 and 2008, using medical records from hospitals in the districts of Mosqueiro, Outeiro and Cotijuba, in Belém. Results: the majority of injuries occurred in males (67.9%) being 84.8% during leisure, mainly in the dry season (July to December) (88.6%), during the day (92.9%) affecting the feet (88.4%) primarily. Participants received medical assistance in the first hour after the accident (84.4%), with local pain (99.2%) being the main complaint. 11.3% of patients had systemic manifestations. Among the complications during evolution, local infection and infection with necrosis were the most frequent (1.7%). Wound debridement was performed in 89.2% of patients. Conclusion: stingray injuries represent an important health problem for the population of the Brazilian Amazon. Understanding its epidemiological and clinical characteristics may improve patient care in the region. [ABSTRACT FROM AUTHOR]

Thorichthys panchovillai, new species, is described, from distinctive of the tributaries of the River Coatzacoalcos basin, Mexico. The new species is diagnosed by a set of characters: dorsal fin rays XVI, 8 – 9; anal fin rays VII, 6 – 7; pectoral fin rays, I, 11 – 12; total gill-rakers on the first branchial cleft 11 – 12; subopercular stain present although weakly intensified, it exposes a notable sexual dimorphism that distinguishes it from others: the female possess a black blotch between the fifth and sixth dorsal spine.

Este trabajo presenta información taxonómica preliminar de la comunidad de fitoplancton del río Colorado, el límite natural entre las provincias de La Pampa y Río Negro. Con el objetivo de conocer y clasificar las comunidades de algas de fitoplancton, se recolectaron muestras en Villa Vieja, en la orilla izquierda. El área de estudio está ubicada en 38º 14 ’55’ S; 67 ° 11 ’49’ W a 232 msnm, aguas abajo de la presa Embalse Casa de Piedra. Los resultados corresponden a muestras tomadas en febrero de 2010, el período de máximo flujo. Las muestras se recolectaron con una red de plancton de 20 micras de abertura observada in vivo y luego se fijaron en formalina (4%). Para estudios de diatomeas, partes alícuotas de las muestras y tratamiento posterior para la eliminación de materia orgánica y la preparación de preparaciones de diatomeas. Los datos fisicoquímicos y ambientales se registraron in situ mediante el uso de sensores portátiles y técnicas de laboratorio posteriores. De todos los taxones identificados para el presente grupo funcional registrado fueron: 32.7% Bacillariophyceae, Chlorophyceae 44.3%, Cyanophyceae 11.5% y 11.5% de otras algas restantes, incluidas las Euglenophyceae.

Es bien sabido que desde su publicación en 1967, Los peces Argentinos de Agua Dulce de Ringuelet, Arámburu y Arámburu constituyó, por un lado, una sinopsis definitiva en su momento de los conocimientos sobre la ictiofauna continental argentina, y que por otro lado posibilitó en gran medida los desarrollos producidos en los últimos diecinueve años. Como no puede ser de otra manera, ha habido modificaciones en la taxonomía de varios grupos, muchos no totalmente depurados y la cantidad de información biológica agregada posiblemente equivalga a la contenida en el libro (véase López et. al., 1981; 1982; 1986, en prensa y López, 1984). Por otra parte, hay una considerable cantidad de adiciones y modificaciones a la ictiofauna. La puesta al día de la nomenclatura, y el registro de nuevas entidades para el área son los principales objetivos de esta lista que constituye un complemento o actualización de la fauna enumerada en Ringuelet, et. al. (1967). Nos hemos enfrentado con el problema de considerar o no las profundas modificaciones que se han propuesto en los últimos años para la sistemática de los ostariofisos. El criterio seguido ha sido el de utilizar en la macrosistemática el esquema de Greenwood, et al. (1966), y para el suborden Characoidei la clasificación Gery (1972) y algunos criterios de Gery (1977). Hemos restringido la lista a la información básica, a saber: los autores de géneros y especies, la fecha de descripción, y las referencias bibliográficas a aquellos trabajos que fundamentan las modificaciones o agregados realizados. Las especies introducidas se indican con un asterisco y las limítrofes con esta indicación, y entre paréntesis cuando se señala su número.

La presente lista constituye el segundo suplemento a la Bibliografía de los Peces de Agua Dulce de !a Argentina y Uruguay 1967-1981 (Biol. Acuática Nº 1, 1981 y N° 3, 1982, Supl.). A través de opiniones publicadas sobre la primera entrega (Copeia, 1983 (1): 284; Trop. Fish Hobb., April, 1982: 53), los autores confirmaron su impresión sobre la utilidad de estas compilaciones, ya que aparen temente, de otra manera, una porción considerable de la producción ictiológica del área del Plata permanecería inaccesible para muchos sectores. Los criterios que sustentan la inclusión de los trabajos son los señalados en 1981. Se incluyen los artículos posteriores a 1982 referidos a material argentino y los de índole general que se consideran pertinentes. Los anteriores a esa fecha sólo se indican cuando no figuran en Ringuelet et al., 1967. Se mencionan las especies citadas, salvo cuando figuran directamente en el título o su número es excesivo. Entendemos que de esta forma aumenta considerablemente la utilidad de la lista, sobre todo en el caso de las obras de difícil obtención.

En el medio argentino que nos toca frecuentar, el de la Ciencia, padecemos de algunos excesos y de algunas carencias. Su cultivo, su desarrollo y su expresión adolece de una exigüidad alarmante de los caminos y medios de difusión. Tenemos escasas vías de comunicación, y los biólogos de todo nivel se enfrentan a menudo ante encrucijadas que no pueden trasponer. Una salida es publicar en revistas científicas del exterior, en idiomas bárbaros, pagando cada página en dólares, o bien comprimiendo el original en algunas revistas nacionales semipagas, o simplemente no imprimiendo el fruto de su trabajo. Creemos que toda solución, si la hay, deber ser autógena, y no de transfretanos temporarios y complacientes. El Instituto de Limnología (ILPLA), que es uno de los hijos activos y dóciles del CONICET, tiene un órgano de publicidad, Limnobios, que tiene 5 años de antigüedad. No obstante, varios trabajos, que por su extensión inevitable no encuadran en las normas tipográficas y económicas corrientes, exigen algún medio publicitario. Biología Acuática, el nuevo órgano de publicidad del ILPLA, costeada en su inicio mediante fondos particulares de algunas pocas personas inconformistas pero crédulas, trata de llenar este vacío.

By using the Braun Blanquet school methodology, two classes, three orders, three alliances and six associations Eastern Cuba's freshwater grasslands were encounters, these groups of class, two orders, two alliances and five associations were described for the first time.

Aquatic macroinvertebrates, and especially insects, are the group of organisms most commonly used to determine the health of ecosystems in water quality studies and freshwater biomonitoring. The most important scientific collection of this group in Costa Rica is located in the Zoological Museum of the University of Costa Rica (MZUCR) and includes material from scientific research, thesis and student projects, as well as samples from environmental studies and aquatic monitoring by consultants and institutions. In this work, an updated list of the collection's material is presented, which includes 98 families and 341 identified taxa (genera, tribes or subfamilies) from eleven insect orders, with Coleoptera and Diptera as the most taxonomical diverse orders. Studies which resulted from revisions of the collection material are cited, including new species, genera, and family records, as well as descriptions of new species and associations of immature stages with their adults. The main challenges for this collection include the taxonomic identification of certain groups, keeping up with the constant collection growth and updating the associated database. [ABSTRACT FROM AUTHOR]

Pacific and Atlantic-slope rivers of the Isthmus of Tehuantepec in Mexico contain two cichlid species of the genus Vieja relevant to the current study, V. zonata and V. coatlicue, respectively. The Atlantic-slope species was initially considered a population of uncertain taxonomic status and recently described as a distinct species based on three putatively diagnostic morphological characters. The objective of this study was to combine new and existing genetic data, along with reanalysis of morphological characters, to test the distinctiveness of V. coatlicue. Little genetic variability and no geographic structuring were recovered. Additionally, putatively diagnostic morphological character states were present across both species, failing to separate the forms. The synthesis of molecular and morphological data supports the recognition of V. coatlicue as a junior synonym of V. zonata. [ABSTRACT FROM AUTHOR]

Bird populations are limited by internal factors such as immigration and migration as well as external factors such as competing for food with other species. The Snail-Kite (Rostrhamus sociabilis) and the Limpkin (Aramus guarauna) share their habitat both of them feed almost exclusively in Apple-Snails (Pomacea). In this document we report on the distribution and abundance of both species, as well as their preferred size of prey at Laguna Bacalar in Quintana Roo, Mexico. From June 2012 to August 2013 we conducted 10 field expeditions and surveyed 36 transects of 500 m each. Snail-Kites and Limpkins were always present in Laguna Bacalar. We observed 319 Snail-Kites; 181 adults, 87 juvenile and 66 indeterminate sex birds. Of the adults 67% were males and 33% female. Their monthly average abundance was 63.3 ± 46.2 individuals. As for the Limpkins, 339 were recorded; their monthly average abundance was 73.3 ± 82.8 individuals. We found evidence of prey selection by size compared with the snails available in the lagoon. Average siphonal length (LS) of snails consumed was 37 ± 0.56 mm. (n= 4312). The smallest LS depredated was 17 mm and the largest of 55 mm. Of snails available in the environment, the average LS was 33 ± 2.82 mm. We recommend further research be conducted on diet and reproductive ecology of both species and on the human consumption of snails in order to provide advice for their management and conservation. [ABSTRACT FROM AUTHOR]

Pomacea flagellata es un caracol conspicuo de zonas tropicales y subtropicales de América, que se ha consumido desde tiempos prehispánicos y actualmente es considerado sobreexplotado. Se realizó un experimento de cultivo de cuatro meses para determinar: la selección del substrato por la hembra, el tamaño de las huevas, el nivel del agua elegido para colocar la masa de huevos, el número de crías, y el tiempo de eclosión. Se utilizaron tres tinas de plástico que se llenaron con 100 L de agua, por duplicado y se colocaron tres sustratos: raíces de mangle, carrizo y tubo de PVC. Se registraron 57 huevas, 26 de ellas eclosionaron produciendo 5037 crías. Hubo más huevas en la “pared” de las tinas, donde se registraron 35 huevas, en raíces de mangle (18), en PVC 3 y en carrizo una hueva. Hubo diferencias significativas en la selección del sustrato, mientras que no se observaron diferencias significativas entre el número de huevas y las proporciones de sexos. La longitud promedio de la masa fue 32.99 ± 10.92, el ancho 16.44 ± 5.1 y grosor 8.08 ± 3.87 mm. La altura promedio de la puesta fue 15.66 ± 3.42 cm, con un tiempo medio de eclosión, de 13.30 ± 2.6 días, obteniéndose entre 94 a 301 crías por desove. Los caracoles utilizaron preferentemente las paredes de las tinas y es difícil determinar si no seleccionan sustrato para la puesta. El nivel del agua empleado es óptimo y permite que los organismos puedan colocar las masas de huevo, la producción de crías es adecuada y suficiente para iniciar programas de cultivo de producción de carne o de repoblación del medio natural.