Invasive bivalve assessment in the diet of pejerrey, Odontesthes bonariensis (Valenciennes, 1835), at the Upper R
ıo de la Plata, Argentina

BRANCOLINI, F.; MAROÑAS, M. E.; SENDRA, E. D.; COLAUTTI, D. C.

JOURNAL OF APPLIED ICHTHYOLOGY-ZEITSCHRIFT FUR ANGEWANDTE ICHTHYOLOGIE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 31 p. 736 - 739

0175-8659

Río de la Plata estuary fish fauna includes several omnivorous predators of native molluscs. Since the arrival of the invasive species Corbicula fluminea and Limnoperna fortunei, many fish species have included them in their diets. It has been found that invasive bivalves accumulate contaminants. The aim of this study is to assess mollusc occurrence in the pejerrey diet at the Upper Río de la Plata estuary, focusing on the relative importance of exotic bivalves. Samples of pejerrey were obtained during 2006, 2007 and 2008. The feeding analysis was made in a stratified way, characterising the pejerrey diet by 50 mm length class intervals. Food items were terrestrial insects, fish, vegetal remains, molluscs and arachnida. Four native and two exotic molluscs were identified as pejerrey prey. Of the mollusc fraction, L. fortunei was present in medium size pejerrey and C. fluminea was important, in number and in volume, for pejerrey larger than 350 mm. Invasive moluscs could have facilitated a new pathway through which contaminants can be incorporated into the food web of the main target species for sport and commercial fisheries in the Upper Río de la Plata estuary.