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Résumé :
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The aim of this paper is to describe the diet of an intertidal population of Gobius paganellus from the Cantabrian coast, looking at seasonal and ontogenetic shifts and identifying the main prey. G. paganellus is an intertidal fish widely distributed on the Iberian Altantic coast. The specimens were captured on the west coast of Asturias (northern Spain). A total of 292 stomach contents were studied. A frequency of occurrence of 99.0% and a numerical composition of 93.0% for arthropods were calculated. The preferential prey items were amphipods and copepods. Isopods, decapods (Natantia), ostracods, leptostracans and acari were secondary prey. So were tanaids, decapods (Brachyura and Anomura) and Diptera larvae, but only for certain sizes and times of the year. A correlation between predator size and the frequency of occurrence of some prey items was found. It was negative for the copepods and ostracods and positive for the leptostracans and decapods, which is obviously related to their respective size. Moreover, a seasonal study of the diet showed significant differences in the contribution of copepods and isopods during certain times of the year, possibly due to larger numbers of smaller sized predators and/or the availability of prey.
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