Does the freshwater mussel Anodonta anatina remove the fish pathogen Flavobacterium columnare from water?

Abstract

Global decline of freshwater mussels (Unionoida) is threatening biodiversity and the essential ecosystem services that mussels provide. As filter-feeding organisms, freshwater mussels remove phytoplankton and suspended particles from the water. By filtering bacteria, freshwater mussels also decrease pathogen loads in the water. The objective of this study was to evaluate whether the common freshwater bivalve Anodonta anatina (duck mussel) could remove the bacterial fish pathogen Flavobacterium columnare from the water. Mussels reduced bacteria in both of the two experiments performed, so that the bacterial concentration at the end of the 96-h monitoring in mussel treatments was only 0.3–0.5 times that of the controls. Surprisingly, mussels did not reduce algal cell concentration statistically significantly. Mussel behavior (shell openness, foot position, and movement) was not affected by the presence of bacteria or algae, except for biodeposition formation, which was greatest in algal-fed treatments, followed by bacterial-fed treatments and controls, respectively. The intestines of bacteria-incubated A. anatina harbored F. columnare, suggesting that mussels ingested the bacteria. Present results suggest that freshwater mussels may also have a potential to mitigate aquaculture pathogen problems, as well as play a role in water quality management.

Influence of Bed Roughness on Flow and Turbulence Structure Around a Partially‐Buried, Isolated Freshwater Mussel

“…They play an important role in many fluvial environments by increasing the sustainability of stream ecosystems (Marion et al., 2014). For example, they constitute a fundamental link in many food chains (Howard & Cufey, 2006; Vaughn et al., 2004, 2008), contribute to the filtration of suspended material (Hajisafarali et al., 2022; Kreeger et al., 2018), provide habitat for fish and insects (Gutiérrez et al., 2003) and can be used as bioindicators for water quality (Doucet et al., 2021; Haag, 2012). A full understanding of the ecological roles played by mussels requires an interdisciplinary approach involving ecological, biomechanical and environmental fluid mechanics research tools (Nikora, 2010).…”