Trophic relationships in Crustacea Decapoda of a river with floodplain.

COLLINS P.; WILLINER V.; GIRI F.

Predation in Organisms: A Distinct phenomenon

Ashraf M. T. Elewa (Editor). Springer Verlag

Lugar: Heidelberg; Año: 2006; p. 59 - 86

Abstract: This review deals of trophic relationships of crustacean decapods in rivers with a floodplain. To do so the feeding aspects of some represents of four families (Sergestidae, Palaemonidae, Trichodactylidae and Aeglidae) of neotropicals decapods were analysed. Freshwater prawns and crabs are considered to be not only predators but also preys being important elements in the food chain of large rivers. This group is found everywhere in the Parana systems, ranging from rivers to wetlands, from pelagic to semi terrestrial areas, from free vegetation, such as beaches, to vegetated areas. These crustaceans take part in the matter-energy exchange between aquatic and terrestrial systems. This occurs because they constitute a source of food for terrestrial and aquatic animals. Approximately, 85% of the feeding ecology of prawns (Sergestidae and Palaemonidae) and 45 % of crabs (Trichodactylidae and Aeglidae) of the Paraná River and its main tributaries has been studied. From the data obtained from stomach content analyses, it is evident that the diet of these decapods is mainly omnivorous, using different trophic levels (plant remains, algae, zooplankton, insect larvae, and oligochaetans, among others). Resource use may vary according to diverse cycles (ontogenetic, ecdysis cycle, daily, annual etc.) and also to the inter and intraspecific competitive pressure. Keywords: Natural feeding, alluvial valley, freshwater, crabs, prawns, stomach contents analysis.