%0 Journal Article
%T Hydrological stress as a limiting factor of the invasion of Limnoperna fortunei (Dunker, 1857) in the Upper Paran¨¢ River (Brazil) Estresse hidrol¨®gico como fator limitante para a invas o de Limnoperna fortunei (Dunker,1857) no Alto Rio Paran¨¢ (Brasil)
%A M£¿nica de C¨¢ssia Souza Campos
%A Rosane Lanzer
%A Paulo de Tarso Castro
%J Acta Limnologica Brasiliensia
%D 2012
%I 
%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. Limnoperna fortunei (Dunker, 1857), ¨¦ um molusco asi¨¢tico que chegou na Am¨¦rica do Sul em 1991. Desde 2004 verificamos que o avan o da esp¨¦cie no Baixo Rio Parana¨ªba, afluente do Alto Rio Paran¨¢, ¨¦ lento quando comparado com a velocidade m¨¦dia de 240 km/ano nos cursos m¨¦dio e baixo do rio Paran¨¢. OBJETIVO: O objetivo deste trabalho ¨¦ entender quais s o os fatores limitantes da dispers o de L. fortunei neste trecho do rio Parana¨ªba. M¨¦TODOS: Sua ocorr¨ºncia e dispers o foram amostradas doze vezes entre mar o de 2006 e novembro de 2007 no rio Parana¨ªba, incluindo o reservat¨®rio da usina hidrel¨¦trica de S o Sim o. RESULTADOS: Mexilh es adultos foram encontrados aderidos aos cascos dos barcos que circulam neste trec
%K Limnoperna fortunei
%K esp¨¦cies invasoras
%K Bacia do rio Paran¨¢
%K mexilh o dourado
%K Limnoperna fortunei
%K invasive species
%K Paran¨¢ River watershed
%K golden mussel
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-975X2012000100007