Adaptation of the predator to new offer trophic: consumption Limnoperna fortunei 20 years after entering the Plata basin

DANIELA DUCHINI; SYLVESTER FRANCISCO; BOLTOVSKOY DEMETRIO

Buenos Aires

Congreso; Marine & Freshwater Invasive Species: Ecology, Impact, and Management; 2016

Aquatic Ecosystems Health and Management Society

Limnoperna fortunei (Dunker, 1857) is an invasive freshwater bivalve which was introduced in the Río de la Plata estuary around 1990. Its dispersion upstream in the Uruguay River, and The Paraná- Paraguay rivers. From ingress to these ecosystems, L. fortunei became part of the diet of many predators, including mammals, birds, fish and invertebrates of various sizes. A study found that 10 years ago predators eliminated around 80% of the biomass of this mussel. In this paper we compare consumption rates observed 10 years ago in the initial phase of colonization, with current consumption rates. For this, method carried out in the 2002-2004 study are replicated, conducting experiments inclusion / exclusion of predators in unprotected and protected cages by mesh cages with different pore size (5, 15 y 40 mm). Preliminary results indicate that there is currently greater consumption of mussels half sizes (4-15 mm), whereas 10 years ago the most consumed sizes were lowest (