The oesophago-intestinal junction in the Dorylaimoidea (Nematoda)

Summary

The oesophago-intestinal junction of 58 species of Dorylaimoidea (sensu Goodey, 1963) are illustrated from whole mounts and eight from sections. In the Dorylaimidae the oseophago-intestinal valve fits into the base of the oesophagus, has a narrow lumen and its posterior end has a non-perforate, non-muscular sheath in the intestine. Seven basic patterns of junction are proposed: dorylaimid ; leptonchid (valve lumen wider, no sheath) ; longidorid (valve reduced) ; belondirid (valve lumen wide, no sheath) ; nygolaimid (three oesophago-intestinal glands) ; aporcelaimid (oesophago-intestinal disc, sheath sometimes present) ; actinolaimid (basal oesophageal shield, sheath sometimes present). Changes from the dorylaimid junction are correlated with factors such as presence of an oesophageal sheath or shortening of the oesophageal bulb.