Field study of freshwater clams Pyganodon grandis, Lampsilis siliquoidea and Ligumia nasuta: habitat preference based on food abundance.

Abstract

The adaptationist paradigm leads us to believe that organisms have evolved adaptations to allow them to live in the environments in which they live. In this project, we ask whether or not organisms live in those environments in which they are best adapted for and also what environmental factors make one environment preferable to another. We use three species of freshwater clams from Douglas Lake, Cheboygan Co., Michigan. Pyganodon grandis, Lampsilis siliquoidea and Ligumia nasuta, and compare abundances to that of food abundance and also substrate particle size, environmental factors that may be important in habitat selection. We found non-significant positive trends in food abundance to clam abundance. Substrate particle size also did not show any significant relation between clam or food abundance. Our results suggest that clam habitat preference is not based on food abundance and particle size. While the results showed no significance, future experiments could increase the sample size and narrow the scope of preferable food items to enhance possible correlations.