Search

Soil seed banks serve as reservoirs of taxonomic and genetic diversity and can buffer the effect of perturbations on plant communities, and thus are critical for community resilience. We studied the relationship of seed bank abundance and richness with different hydrological attributes, evaluated beta diversity patterns among wetlands in the Middle Parana River floodplain, and experimentally explored soil seed bank germination after a drought period. Seed abundance was positively related to drought intensity and, along with richness, negatively related to drought and flood frequency. Turnover and balanced variation in abundance greatly contributed to the total beta diversity probably associated with the environmental heterogeneity of the floodplain; nestedness had a lower contribution probably associated with different dispersal abilities of species. Germination behavior varied between rooted and free-floating plants. In conclusion, the soil seed banks studied are highly variable among habitats; drought and flood frequency, and drought intensity are related with the seed banks abundance and richness; and the germination responses after a drought phase differ among broad ecological groups of wetland plants.

Toxicants on fish may induce genetic alterations that can be used as genotoxic markers. We evaluated DNA damage using alkaline comet assay applied on erythrocytes after in vivo exposure of Prochilodus lineatus to different concentrations of Cypermethrin (0.300, 0.150, 0.075 and 0.000 µg/L) as a probable chemical mutagen. The results revealed a significantly higher level of DNA damage at all concentrations of Cypermethrin tested compared to control and background level (p

All animals face the possibility of limitations in food resources that could ultimately lead to mortality caused by starvation. The primary goal of this study was to characterize the various physiological strategies that allow fish to survive starvation. A multiparametric approach, including morphological biomarkers, blood plasma metabolites, oxidative stress and energy reserves, was used to assess starvation effects on the fish Hoplosternum littorale. Adult specimens were maintained at four experimental groups: control (fed ad libitum), and starved (not fed) fish for 7 and 28 days. Significant changes were observed not only after 28 days, but also after 7 days of starvation. In the shorter period, the hepatosomatic index as well as plasma triglycerides and glucose were significantly lower in starved fish than in the control ones. These results were accompanied by reduced lipid, glycogen and protein reserves in liver and diminished glycogen content in muscle, suggesting the need of these macromolecules as fuel sources. In addition, increased antioxidant enzyme activities were observed in gills, without evidence of oxidative stress in any of the evaluated tissues. Most significant differences were found in 28-days starved fish: total body weight together with the hepatosomatic index was lower when compared to control fish. The plasmatic metabolites tested (glucose, triglyceride, cholesterol and protein), all energy reserves in liver and glycogen content in muscle decreased in 28-days starved fish. Lipid oxidative damage was reported in liver, kidney and brain, and antioxidant enzymes (GST, GR, GPx and CAT) were activated in gills. According to the multivariate analysis, oxidative stress markers and metabolic parameters were key biomarkers that contributed in separating starved from fed fish. Our study allowed an integrated assessment of the fish response to this particular condition. Fil: Rossi, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Bacchetta, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Campana, Mirta Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Parma, Maria Julieta E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina

The combined effects of two synthetic insecticides on a wide array of biomarkers in the freshwaterfish Piaractus mesopotamicus were studied. Fish were exposed to sublethal concentrations of endosul-fan (ED), lambda-cyhalothrin (LC), and the combination of both pesticides for 96 h. The set of analyzedbiomarkers included morphometric and hematological parameters, transaminases and alkaline phos-phatase activities, antioxidant enzymes activities and oxidative damage biomarkers measured in gills,liver, kidney, brain and muscle. According to the principal component analysis, the most significant effectswere produced by the ED?LC combination. So, the mixture of both insecticides produced an increase inthe liver-somatic index, hematological changes related to immunological biomarkers (increased whiteblood cells count, and alterations in the differential leukocytes count), decreased liver transaminasesactivity, antioxidant enzymes induction in almost every tissue, and lipid peroxidation levels increases inliver, kidney and brain of exposed fish. Our results suggest deleterious effects of ED and LC insecticidesin combination, and support the usefulness of the multi-biomarker approach for the characterization oftoxicological mechanisms induced by pesticides. Fil: Bacchetta, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Rossi, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Ale, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Campana, Mirta Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Parma, Maria Julieta E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina

El cambio de hábitos en el tipo de colación de los escolares está relacionado, principalmente, con las promociones de los kioscos escolares. Los objetivos del trabajo fueron conocer los productos preferidos comprados en los kioscos escolares para la colación y las razones de su elección (en dos escuelas primarias públicas de la ciudad de Santa Fe) y determinar si las restricciones y exigencias de ventas influyen en la selección de una colación saludable. Los datos fueron recolectados mediante dos encuestas: áulica y en boca de kiosco. La mitad de los niños compra la colación en el kiosco escolar, un 35 % aproximadamente trae colación del hogar, siendo ésta, mayoritariamente, recomendable. Existen diferencias significativas entre las proporciones que eligen un alimento ?recomendable? en el kiosco escolar en ambas escuelas. El principal motivo de selección es el gusto. Es importante regular la venta de productos en los kioscos escolares y educar a los niños en la elección de los alimentos para que realicen una colación saludable. Thirty stomach–content samples (n = 30) were analyzed belonging to the Yellow– billed Tern from the floodplain of the Middle Paraná River, Argentina. The trophic spectrum was composed of 12 taxa (all animal fractions). IRI values were fish= 18 000, crustaceans = 550 and insects = 300. The Hk was 1,52. Regarding the circadian rhythm of feeding activity, an increased activity was observed during midday hours. Food efficiency was 98 % in spring, 99 % in summer, 96,5 % in autumn, and 95,9 % in winter. Prey size ranged from 20–60 mm, being more frequent in the range of 20–40 mm (corresponding to H. pequira). The habitat use index yielded a value of 0.5 for the beach or shore unit. S. supercilliaris presents a carnivorous diet, basically ichthyophagous, whose optimal foraging is linked to the abundant supply of aquatic resources. Fil: Olguin, Pamela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto Nacional de Limnologia (i); Argentina; Fil: Beltzer, Adolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto Nacional de Limnologia (i); Argentina; Fil: Campana, Mirta Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto Nacional de Limnologia (i); Argentina

Prochilodus lineatus, a fish, was exposed to sublethal concentrations of cypermethrin: 0.075, 0.150, and 0.300 μg L−1 and a control group (without cypermethrin) for 96 h. Five specimens were exposed in each concentration for triplicate (n = 60). Hepatic biochemical values and behavioral changes were studied. The results revealed a significantly higher level of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hepatic tissue at different concentrations of cypermethrin tested compared to control (p < 0.05). A decrease in total protein was observed in exposed groups but not significantly (p > 0.05). This study provides information to know toxic mechanisms of cypermethrin on hepatic enzymes of P. lineatus that are poorly understood. Fil: Loteste, Alicia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Scagnetti, Jorge Alberto Jesus. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Simoniello, Maria Fernanda. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Campana, Mirta Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Parma, Maria Julieta E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina