Substrate selection by the freshwater mussel Diplodon chilensis (Gray, 1828): field and laboratory experiments.

To evaluate the capacity for movement of freshwater mussels in sandy and sand-gravel substrates and to test their ability to differentiate among types and qualities of substrates, experiments were carried out in the laboratory and in the field, using Diplodon chilensis from Lake Panguipulli, Chile. The movement of mussels was greater in sandy than in sand-gravel substrates. In the absence of food, there was a significant preference for sandy substrate, and when mussels were offered sandy or sand-gravel substrates with and without food they chose the substrate with food with no preference to substrate type. Under natural conditions mussel presence and abundance along time is regulated by variables with a synergistic effect, niche of which substratum is not always the major one. [ABSTRACT FROM AUTHOR]