%0 Journal Article %T Hydrological stress as a limiting factor of the invasion of Limnoperna fortunei (Dunker, 1857) in the Upper Paran¨¢ River (Brazil) %A Campos %A M£¿nica de C¨¢ssia Souza %A Lanzer %A Rosane %A Castro %A Paulo de Tarso %J Acta Limnologica Brasiliensia %D 2012 %I Scientific Electronic Library Online %R 10.1590/S2179-975X2012005000027 %X limnoperna fortunei (dunker, 1857), is an asiatic mussel that arrived in south america in 1991. since 2004, we have noticed that the advance of this species in the lower parana¨ªba river, a tributary of the upper paran¨¢ river, is slow when compared to the average speed of 240 km/year in the paran¨¢ river (middle and lower course). aim: the goal of this work is to understand what factors are limiting the spread of l. fortunei in this stretch of the parana¨ªba river. methods: its occurrence and dispersion were sampled twelve times between march 2006 and november 2007 in the parana¨ªba river, including the s£¿o sim£¿o hydroelectric reservoir. physicochemical characteristics of the water were analysed, and a stream length-gradient index calculated for the study area. results: adult mussels were easily found attached to the hulls of barges that travel on this stretch of the paran¨¢-tiet¨º waterway and on vessels that were docked in the harbours of grain exporters located in s£¿o sim£¿o (go). however, no larvae or adults were found near the harbours or upstream from them at the s£¿o sim£¿o hydroelectric reservoir. the ph and concentration of calcium and dissolved oxygen values among lotic habitats and the reservoir were similar: do values were close to 7 mg.l-1, the average ph was near 7, average values of total ca ranged between 4 and 6 mg.l-1 and the chlorophyll-a levels were not restrictive to the mussel. conclusion: physical and chemical water parameters show that habitats were suitable for establishment of the mussel. in addition to a low pressure of propagules, this paper proposes some hydrological variables, such as the energy of the fluvial stretches, expressed by the stream length-gradient index and changes in flow downstream of the dam as barriers to the establishment of the species, discouraging larval settlement, and decreasing survival and recruitment. %K limnoperna fortunei %K invasive species %K paran¨¢ river watershed %K golden mussel. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S2179-975X2012000100007&lng=en&nrm=iso&tlng=en