SEM study of semi-oriented tube microstructures of Serpulidae (Polychaeta, Annelida): implications for the evolution of complex oriented microstructures

Abstract

Semi-oriented microstructures represent an intermediate state between isotropic and complex oriented microstructures of serpulids. Semi-oriented microstructures are apparently unique to serpulids, indicating that there may have been unique aspects in the evolution of their biomineralization system. The occurrence of semi-oriented microstructures in serpulids supports the hypothesis that complex oriented microstructures are derived from isotropic microstructures via evolution of a biochemical crystal orientation control mechanism.