INALI   02622
INSTITUTO NACIONAL DE LIMNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
POPULATION DYNAMICS OF THE ASIAN MUSSEL LIMNOPERNA FORTUNEI ASSOCIATED WITH MACROPHYTES IN THE PARANÁ RIVER
Autor/es:
MUSÍN GABRIELA ELIANA; ROJAS MOLINA FLORENCIA; WILLINER VERÓNICA
Lugar:
Mar del Plata
Reunión:
Congreso; BIOLIEF 2011 ? 2nd World Conference on Biological Invasions and Ecosystem Functioning; 2011
Institución organizadora:
Grieta
Resumen:
The Paraná River floodplain presents a high density of aquatic macrophytes among witch the floating Eichhornia crassipes is the most abundant in coverage and biomass. The roots-system of this macrophyte provides habitats for invertebrates, including substrate for the Asian invasive bivalve Limnoperna fortunei. This study evaluated the density variation and size structure of L. fortunei on the roots of E. crassipes in the Middle Paraná floodplain. Between November 2009 and April 2010, during a period of high water, bivalves were monthly sampled in two lakes. In each site physico-chemical variables were registered and three replicate samples of E. crassipes were taken. In the laboratory the roots were washed and screened to obtain the molluscs. Mean densities were 117.5 ind.m-2 in Irupé lake and 1288.3 ind.m-2 in Mini Lake and the variation data were non-significant (M-W: U= 133.5, p= 0.728) between them. The highest densities were registered during November and December (up to 7634.6 ind.m-2) and after these values dropped in the following month (<1 ind.m-2 in April), without register in March. Differences in mollusc sizes were statistically significant between lakes (M-W: U=15787, p<0.001), over 60% of the mussels were <4mm in total length in Mini Lake and between 3 and 7 mm in Irupé Lake. On the basis of previous studies, the population corresponded to individuals about two year-old (maximun= 19.4 mm in lenght) largely dominated by individuals under-age one year-old. This is the first study of population dynamic of L. fortunei in the Middle Paraná River associated with macrophytes.