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Migratory movements of pacu, Piaractus mesopotamicus, in the highly impounded Paraná River

January 1, 2007

A mark-recapture study was conducted in 1997–2005 to investigate movements of stocked pacu, Piaractus mesopotamicus, in the Paraná River Basin of Brazil, Paraguay, and Argentina. Fish raised in cages within the Itaipu Reservoir and in ponds were tagged externally (n = 2976) and released in the Itaipu Reservoir (53.2%) and bays of its major tributaries (46.8%). In total, 367 fish (12.3%) were recaptured. In all, 91% of the pacu moved away from the release site; upstream movements were more extensive than downstream movements. Pacu traveled upstream a maximum of 422 km (average of 41.3 km) at a maximum rate of 26.4 km day−1 (av. 0.8). Downstream movements were limited in terms of number of individuals and distance moved. Fish released during the wet season moved farther than those released during the dry season, and feeding rather than spawning might have been the compelling reason for movement. Although fish passed downstream through dams, none of the marked fish were detected to have moved upstream through the passage facilities. Pacu showed movement patterns not radically different from those of other neotropical migratory species, but their migratory movements may not be as extensive as those of other large migratory species in the basin.

Citation Information

Publication Year 2007
Title Migratory movements of pacu, <i>Piaractus mesopotamicus</i>, in the highly impounded Paraná River
DOI 10.1111/j.1439-0426.2007.01006.x
Authors M.C. Makrakis, L.E. Miranda, S. Makrakis, A.M.M. Xavier, H.M. Fontes, W.G. Morlis
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Applied Ichthyology
Series Number
Index ID 70031216
Record Source USGS Publications Warehouse
USGS Organization