The response to increased total suspended solids is plastic in juvenile unionids

Session: 48. - Physical Ecology in Large Lakes and their Watersheds

Shaylah Tuttle-Raycraft, University of Guelph, [email protected]
Josef Ackerman, University of Guelph, [email protected]

Abstract

Increased total suspended solids (TSS) threaten freshwater fauna, including unionid mussels which are highly imperilled. Unionids have decreased feeding (clearance rate; CR) when TSS concentration is increased, however this relationship varies with the source population of the mussels. The source of this variation (i.e. genetic vs. phenotypic plasticity) is unknown, but may be related to the turbidity of the source rivers. Juvenile Lampsilis siliquoidea from the Thames River were transformed in the laboratory and reared in filtered river water, either with or without suspended sediment (50 mg L^-1; 0-63 µm). At 4-weeks old, they were placed into one of six TSS treatments (0 – 25 mg L^-1) for one hour, and CR were calculated and compared. Although the CR of both rearing groups decreased as TSS concentration increased, the river water + TSS group was less affected. The CR was higher than the control (i.e., water only) group in all TSS concentrations except the no sediment control (0 mg L^-1). Understanding the response to TSS at early stages of juvenile development has implications for mussel relocation and reintroduction. These results suggest that rearing conditions may influence how mussels respond to abiotic stress at later life stages.

1. Keyword
unionids

2. Keyword
turbidity

4. Additional Keyword
Suspension feeding