4 resultados para Microscopía electrónica de alta resolucion

em Aquatic Commons


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This thesis explored the relationship between hydrological variability and associated changes in fish communities in the upper Salado river lakes (Pampa plain, Argentina). The sampling design included five sites along the river connected lakes being explored for fish, hydrological and environmental data during different hydrological conditions. The temporal dynamic of main environmental characteristics of these lakes show that hydrology largely regulates some of the most important factors influencing fish ecology. Changes in fish communities associated with this hydrological and environmental dynamic allow to speculate a first approach towards the functioning of the system as a whole. Following oscillation between droughts and floods, study lakes have shown significant changes on abundance of major fish species, as well as on their recruitment success, which finally leaded to marked changes in fish community structure. Interestingly, trophic structure of communities did not change as much. iOdontesthes bonariensis/i was more abundant during droughts and in saltier sites but also displayed an improvement in recruitment success during these harsh abiotic conditions. Conversely, the abundance of iParapimelodus valenciennis, Cyphocharax voga/i and iCyprinus carpio/i as well as its recruitment success, were largely favoured by lower water residence times and total salinity. This dichotomy is mainly based on different life history strategies of these species against flor and environmental variability and it support the existence of different functional groups among the fish species of upper Salado river lakes. iOligosarcus jenynsii/i did not showed as evident functional response. In conclusion, hydrological and environmental variability can be considered as one of the main factors regulating the functioning and structure of fish communities in these very shallow lowland river lakes of the Pampa plain. Following these results some implications for an eventual regulation of the river regime are discussed.

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Versión electrónica para multimedia del libro Corales Pétreos de Cuba publicado en 1980 por Nereida Martínez Estalella y Vasil Zlatarski. La colección de Corales pétreos se formó en el Instituto de Oceanología entre los años 1970 y 1975. En 2005 pasa a ser custodiada por el Acuario Nacional con el resto de las colecciones biológicas. La colección está formada por 4,990 ejemplares, 2 Clases Anthozoa e Hydrozoa , 16 familias, 30 géneros, 45 especies y 23 formas. Multimedia electronic book version of Stony Corals Cuba published in 1980 by Nereida Martínez Estalella and Vasil Zlatarski. The collection of stony corals are formed at the Institute of Oceanology between 1970 and 1975. Renumbered in 2005 by the National Aquarium guarded with other biological collections. The collection consists of 4,990 samples, 2 classes Anthozoa and Hydrozoa, 16 families, 30 genera, 45 species and 23 forms.