Comparative Anatomy of the Stomach of Buccinoidea (Neogastropoda)

Stomach anatomy of 15 species from five families of Buccinoidea has been examined. Stomach anatomy does not depend upon diet, but reflects phylogenetic relationships. Therefore, a combination of stomach characters [presence or absence of the posterior mixing area; presence and degree of development of longitudinal fold(s), separating gastric chamber into ventral and dorsal channels; presence and degree of development of lateral sulcus; position of the digestive gland ducts, and others] allows discrimination of all families of Buccinoidea, except for the closely related Buccinidae and Buccinulidae. The current familial position of the genera Clea, Busycon and Nassaria is questioned from evidence of stomach anatomy. The function of the neogastropod stomach is discussed, with emphasis on food absorption. Observations on the ciliary currents in the stomachs of live specimens suggest that food absorption occurs through the stomach walls, rather than in the tubules of the digestive gland.