Influence of sediment grain size on the burrowing of bivalves; correlation with distribution and stratigraphic persistence of selected Neogene clams

Burrowing ability of 21 species of clams from Oregon, New Jersey, and Scotland was determined in each sieved sediment ranging from fine gravel to mud in half phi increments. A burrowing rate index (BRI), which normalizes burrowing time for specimen mass, was calculated for each species in each sediment. Skewness and kurtosis of the profile of average BRI's across the range of grain sizes was used to categorize species as substrate generalists, substrate sensitive, or substrate specialists. Substrate generalists (Anadara ovalis, Mercenaria mercenaria, Astarte sulcata, Venerupis decussata, Venus striatula, Venus casina, Mya arenaria] burrowed slowly into a wide range of grain sizes