Note
Specimens of Corbicula fluminea from Mississippi show altered internal shell color and microstructure when maintained under stressful conditions. Clams under laboratory conditions that "threaten" life-sustaining functions, as well as field collections of moribund animals, show conversion of typically purple highlighted internal shell to pure white, and conversion of a surficial complex crossed-lamellar microstructure to a form reminiscent of complex crossed-acicular. These changes possibly result from a shift in metabolic activities away from energy expenditures normally allocated to shell production and towards life-sustaining functions.