A new species of Farlowella (Siluriformes: Loricariidae) from the upper Bermejo River, La Plata River basin, northwestern Argentina

A new species of Farlowella is described from the Bermejo River basin, in Salta and Jujuy provinces, northwestern Argentina. The new species belongs to the Farlowella nattereri species group. The new species is diagnosed by the following combination of characters: marbled rostrum, five rows of lateral plates series, relatively short snout (snoutmouth length less than 50.0% of head length), complete half-moon shaped spot on caudal fin, and short predorsal distance (37.8-41.8% of standard length).Se describe una nueva especie de Farlowella de la cuenca del Río Bermejo, en las provincias de Salta y Jujuy, en el noroeste de Argentina. La nueva especie pertenece al grupo de Farlowella nattereri. La nueva especie se diagnostica con la siguiente combinación de caracteres: rostro veteado, cinco hileras de placas laterales en el cuerpo, hocico relativamente corto (longitud hocico-boca menor a 50.0% longitud cabeza), mancha en forma de media luna completa en la aleta caudal, y distancia predorsal corta (37.8-41.8% longitud estándar)Fil: Teran, Guillermo Enrique. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Ballen, Gustavo A. Universidade de Sao Paulo; BrasilFil: Alonso, Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Aguilera, Gaston. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Mirande, Juan Marcos. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

Biodiversidad del Parque Nacional Pre-Delta (Entre Ríos, Argentina). I) Riqueza del fitoplancton

Mirande, V., S. E. Haleblian, G. A. Barreto & B. C. Tracanna. 2009. Biodiversidad del Parque Nacional Pre-Delta (Entre Ríos, Argentina). I) Riqueza del fitoplancton. Lilloa 46 (1-2). El objetivo del presente trabajo fue contribuir al conocimiento de la riqueza del fitoplancton del Parque Nacional Pre-Delta. Hasta el presente se carece de un relevamiento ambiental y ficoflorístico de los cuerpos de agua de este parque, aunque sí se dispone de datos geomorfológicos, faunísticos y florísticos. Se seleccionaron siete sitios de muestreo correspondientes a ambientes lóticos y leníticos. Para la extracción de las muestras cualitativas se filtraron 32 litros de agua a través de una red de 20 µm de poro, las cuales fueron fijadas “in situ” con formaldehido al 4%. La comunidad estuvo compuesta por 102 especies pertenecientes a Cyanophyceae, Chlorophyceae, Charophyceae, Dinophyceae, Bacillariophyceae, Chrysophyceae, Xanthophyceae and Euglenophyceae, destacándose una mayor riqueza específica en las lagunas. Los resultados obtenidos evidenciaron a las diatomeas como el grupo que en líneas generales más contribuyó en especímenes. Se citan 26 especies y 3 variedades nuevas para el Noreste Argentino y, además de las mencionadas anteriormente, se aportan otras 18 especies y 6 variedades para la provincia de Entre Ríos. Todas las entidades comentadas son nuevos taxa para el área de estudio

Evaluación abiótica y biótica de ambientes acuáticos de un parque nacional entrerriano

Mirande, V.; B. C. Tracanna; S. E. Haleblian; G. A. Barreto. 2012. “Evaluación abiótica y biótica de ambientes acuáticos de un parque nacional entrerriano”. Lilloa 49 (2). El objetivo del presente trabajo fue caracterizar ambientes leníticos y lóticos del Parque Nacional Pre-Delta (Argentina). Se estudiaron siete zonas (tres lagunas, un arroyo y dos riachos). Se consideraron variables abióticas (conductividad, iones mayoritarios, oxígeno disuelto, compuestos nitrogenados, otras) y bióticas (bacterias y fitoplancton), las cuales fueron determinadas mediante protocolos convencionales. Se empleó el análisis de componentes principales (ACP) para la ordenación de los sitios. Los resultados obtenidos evidenciaron una elevada carga bacteriana en los sistemas lóticos, mientras que en las lagunas fue baja o no detectada. Los mayores registros algales de abundancia, biomasa y diversidad se obtuvieron en los ambientes leníticos, opuesto a lo manifestado por las bacterias. Los tres primeros componentes del ACP permitieron explicar el 95% de la varianza total. Los ejes uno y dos separaron las aguas fluyentes de las estancadas, en lo cual contribuyeron tanto variables abióticas como bióticas. Entre las conclusiones se puede destacar que, en orden decreciente, en la separación de los ambientes seleccionados influyeron factores como la carga bacteriana, nitrato, iones mayoritarios, abundancia total y diversidad del fitoplancton, entre otros

COMPUTER SIMULATIONS OF POSSIBLE FUTURES FOR TWO FLOCKS OF WHOOPING CRANES

We conducted computer simulations using the program VORTEX (version 7) to project population sizes, growth rates, genetic diversity, and probabilities of extinction over the next 100 years for 2 flocks of whooping cranes (Grus americana), the Aransas/Wood Buffalo population and the experimental Florida population. Standard runs based on best estimates of demographic. genetic, and environmental parameter values were used as a baseline to which several alternative scenarios were compared. Results generally supported the conclusion of the earlier Population Viability Assessment (Mirande et al. 1991) that the AransaslWood Buffalo population will continue to grow steadily with less than a 1 % probability of extinction. It was noted, however, that a combination of negative factors such as shrinking habitat and increased probabilities of catastrophes accompanied by increased mortality rates could put this population at risk. Results for the Florida population were less optimistic. The standard run produced a population growth rate (r) of only 0.0026 for the next 100 years, and this shifted down to -0.0001 over a 200-year time frame. Adult mortality in this flock would have to be about 20% lower than the predicted value (10%) in order to raise growth rates to above r = 0.02. Amount and duration of supplementation of the Florida flock had minimal impacts on the long-tenn growth rate of the flock. It is the enduring rates of mortality, breeding, and disease risk that will have major effects on this population. For example, if disease risks tum out to be greater than the best-estimate scenario, this population could face a relatively high risk of extinction (17%). The formula for success in Florida is lower adult mortality, lower age of first breeding, lower disease risk, and higher productivity than the best-guess estimates. Fortunately, there are some potential management interventions (e.g., predator control, vaccines and health monitoring, selective introductions to balance the sex ratio of the flock) that may be able to push the odds in favor of success

Molecular phylogeny of the subfamily Stevardiinae Gill, 1858 (Characiformes: Characidae): classification and the evolution of reproductive traits

Abstract Background The subfamily Stevardiinae is a diverse and widely distributed clade of freshwater fishes from South and Central America, commonly known as “tetras” (Characidae). The group was named “clade A” when first proposed as a monophyletic unit of Characidae and later designated as a subfamily. Stevardiinae includes 48 genera and around 310 valid species with many species presenting inseminating reproductive strategy. No global hypothesis of relationships is available for this group and currently many genera are listed as incertae sedis or are suspected to be non-monophyletic. Results We present a molecular phylogeny with the largest number of stevardiine species analyzed so far, including 355 samples representing 153 putative species distributed in 32 genera, to test the group’s monophyly and internal relationships. The phylogeny was inferred using DNA sequence data from seven gene fragments (mtDNA: 12S, 16S and COI; nuclear: RAG1, RAG2, MYH6 and PTR). The results support the Stevardiinae as a monophyletic group and a detailed hypothesis of the internal relationships for this subfamily. Conclusions A revised classification based on the molecular phylogeny is proposed that includes seven tribes and also defines monophyletic genera, including a resurrected genus Eretmobrycon, and new definitions for Diapoma, Hemibrycon, Bryconamericus sensu stricto, and Knodus sensu stricto, placing some small genera as junior synonyms. Inseminating species are distributed in several clades suggesting that reproductive strategy is evolutionarily labile in this group of fishes.http://deepblue.lib.umich.edu/bitstream/2027.42/134621/1/12862_2015_Article_403.pd

Two new species of Odontostilbe historically hidden under O. microcephala (Characiformes: Cheirodontinae)

Specimens historically identified as Odontostilbe microcephala from the upper rio Paraná and Andean piedmont tributaries of the río Paraguay are reviewed and split in three species. We found that the distribution of O. microcephala is restricted to the Andean slope of the río Paraguay basin. The species is distinguished from congeners with subterminal mouth by the elongate body, usually 10-12 gill rakers on upper branch and smaller horizontal orbital diameter (24.6-32.8 % HL, mean 28.7%). Specimens from upper rio Paraná constitute two new species, diagnosed from other Cheirodontinae by the presence of mesopterygoid teeth, grouped on median portion and forming a continuous row. The new species are distinguished from each other by having premaxillary teeth with five cusps vs. nine cusps and by the number of lamellae in left and right sides of central median raphe of olfactory rosette with 20-21 vs. 11-12.Espécimes historicamente identificados com Odontostilbe microcephala do rio Paraná e tributários do río Paraguay, foram revisados e separados em três espécies. A distribuição de O. microcephala é restrita ao sopé andino da bacia do río Paraguay. A espécie é distinta das congêneres com boca subterminal pela forma alongada, geralmente 10-12 rastros branquiais no ramo superior e menor diâmetro horizontal da órbita (24,6-32,8 % CC, média 28,7%). Espécimes do alto rio Paraná constituem duas espécies novas diagnosticadas de outros Cheirodontinae pela presença de dentes no mesopterigoide, agrupados em sua porção média e formando uma fileira continua. As novas espécies distinguem-se por ter dentes premaxilares com cinco cúspides vs. nove cúspides e pelo número de lamelas nos lados esquerdo e direito da rafe central da roseta olfativa com 20-21 vs. 11-12