Feeding and Habitat
Freshwater mollusks feed by filtering the water for various zooplankton, detritus, and other small plants and animals. It has been suggested that they also use a silt and algal mix as food (Watters, 1995). Small amounts of silt have been found to enhance the survivorship in cultured mussels for undetermined reasons (Watters, 1995).
As the food and nutrients enter the shell, the labial palps secrete a mucus that binds the floating particles of food and nutrients together to form a bolus. After the bolus has formed, the cilia located on the labial palps move to form a current within the mussel's protective shell. This current helps to move the bolus of food and nutrients to the mouth were it can be ingested.
After the bolus of food and nutrients have been digested, the waste material is then excreted from the anus and then discarded from the shell, usually by the use of the siphon, if the siphon is present.
Freshwater mollusks live primarily in the benthic regions within their aquatic ecosystem. Exposing only a small portion of their bodies, they bury themselves within sand, silt, mud, or even gravel. The substrate helps to support and secure their heavy shells.
The problem with burying themselves within the substrate is that this leaves them vulnerable to natural and environmental changes. Other aquatic organisms are able to move away from the changing environment, but for the freshwater mussel, their slow movement leaves them vulnerable to desiccation, predation, and other environmental changes, thus decreasing the population size.
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