Structure of Alimentary canal in Branchiostoma/Amphioxus

The alimentary canal in branchiostoma is a straight and complete tube from mouth to anus. It is lined throughtout by ciliated epithelium and its diameters varies in different parts. It consists of various parts: i) Mouth ii) Oral hood and buccal cavity: consists of Oral hood and buccal cirri,vestibule and wheel organ. iii) Velum and enterostome iv) Pharynx: Its possesses: Pharyngeal wall and gill slits, endostyle, epipharyngeal groove, peripharyngeal groove, peripharyngeal bands, v) Oesophagus vi) Intestine and vii) Anus