58 research outputs found
Contribution of anadromous fish to the diet of European catfish in a large river system
Many anadromous fish species, when migrating from the sea to spawn in fresh waters, can potentially be a valuable prey for larger predatory fish, thereby efficiently linking these two ecosystems. Here, we assess the contribution of anadromous fish to the diet of European catfish (Silurus glanis) in a large river system (Garonne, southwestern France) using stable isotope analysis and allis shad (Alosa alosa) as an example of anadromous fish. Allis shad caught in the Garonne had a very distinct marine delta(13)C value, over 8 per thousand higher after lipid extraction compared to the mean delta(13)C value of all other potential freshwater prey fish. The delta(13)C values of European catfish varied considerably between these two extremes and some individuals were clearly specializing on freshwater prey, whereas others specialized on anadromous fish. The mean contribution of anadromous fish to the entire European catfish population was estimated to be between 53% and 65%, depending on the fractionation factor used for delta(13)C
Riparian ecotones and spatial variation of fish assemblages in Portuguese lowland streams
The first results of a long-term study on the role of riparian ecotones on the population and community
dynamics of Iberian stream fish are presented and discussed . Riparian and macrophyte cover, bank
slope and depth were among the most important variables affecting fish distribution . In general small
fish favoured shallow areas with high macrophyte cover, whereas large fish dominated in deep areas with
a high riparian cover . Slight spatial changes in terrestrial prey use were found suggesting a minor role
for this resource during autumn . Finally, no significant spatial differences were found for linear growth,
although some differences were obtained for the condition facto
The apoptotic machinery as a biological complex system: analysis of its omics and evolution, identification of candidate genes for fourteen major types of cancer, and experimental validation in CML and neuroblastoma
Region-specific DNA synthesis in brains of F344 rats following a six-day bromodeoxyuridine infusion
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