Anatomy and ultrastructure of ventral pharyngeal organs and their phylogenetic importance in Polychaeta (Annelida)

摘要: Transmission electron microscopic studies were carried out on the ventral pharyngeal organs in Ctenodrilus serratus and Scoloplos armiger. The are composed of a muscle bulbus tongue-like organ. In both species consists transverse fibres interstitial cells with voluminous cell bodies dorsoventral tonofilaments; investing runs into organ; nuclei located caudal bulges; salivary glands not present, but numerous gland occur epithelium. organ, however, is formed by lateral folds (C. serratus) or bridge-like structure (S. armiger). specific probably homologous characteristic also occurring several other polychaete families. phylogenetic importance this pharynx discussed hypothesis suggested to explain differentiation certain from primitive type.