Mycetopodella falcata (E.T. Higgins, 1868) (Unionida: Mycetopodidae): shell morphology, anatomy of the digestive system, and systematics

Abstract

Mycetopodella falcata (E. T. Higgins, 1868) is a freshwater mussel belonging to the family Mycetopodidae and has been known for over 150 years. Only its shell has been described, and even that, scarcely. We review the geographic distribution of M. falcata and find it not endemic to the Amazon Basin. We also present a highly detailed study of the microstructure of the periostracum and the inner shell layer, characterize the shell and its features, and provide the first morphoanatomical description of the soft parts, especially the alimentary canal. Some structures in its internal shell organization and stomach are found to be unique in the family.