Effects of suspended inorganic matter on filtration and grazing rates of the invasive mussel Limnoperna fortunei (Bivalvia, Mytiloidea)

TOKUMON, R.; CATALDO DANIEL; BOLTOVSKOY DEMETRIO

JOURNAL OF MOLLUSCAN STUDIES

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2015 vol. 2015 p. 1 - 4

0260-1230

Since its introduction in South America around 1990, the Asian invasive mussel Limnoperna fortunei has colonized most of the Río de la Plata watershed, and is expected to invade other basins in the near future. Among the factors that may limit its geographic expansion, the amount of suspended solids plays a major role. In order to contribute first-hand information for models predicting its potential geographic spread, we assessed filtration and grazing rates of adult (15-20 mm) L. fortunei on natural phytoplankton (around 45 µg L-1 chlorophyll a) at different concentrations of suspended bentonite clay: 0, 0.1, 0.5, 1, 2, 4, 6 and 8 g L-1, at 27ºC. At clay concentrations of up to 0.5 g L-1,filtration and grazing rates did not differ significantly from the controls (without clay) (343-466 ml per g of dry tissue weight per h, and 11.6-13.4 µg Chlo a per g of dry tissue weight per h, respectively). However, at clay concentration ≥1 g L-1, both filtration and grazing rates dropped sharply, and were near zero at 4 through 8 g of clay L-1. These results suggest that the golden mussel will be unable to colonize waters where suspended sediments are above 2-3 g L-1, such as those which often occur in many rivers of the world.