Layering, the effective density of mussels and mass-density boundary curves

Overall intraspecific mass-density patterns have seldom been explored in animals. Instead, self-thinning studies have predominated. The analysis of 253 samples in a multilayered mussel showed that the classical approach is biased by layering or crowding effects, suggesting a transition zone between density independence and self-thinning, without a C-D effect. However, when the effective density (density corrected by layer effect) is used, space/allometric constraint expectations are met. Layering and crowding effects on self-thinning and the mass-density boundary should be common in mussels and other taxa showing aggregated distributions.