Fine Structure of the Esophagus of Males of Sarisodera hydrophila (Heteroderoidea)


  • J. G. Baldwin


The fine structure of the esophagus, including procorpus, metacorpus, isthmus, gland lobe, and esophago-intestinal junction, is examined in males of Sarisodera hydrophila. A cuticle-lined lumen extends most of the length of the esophagus, broadens to form a pump chamber in the metacorpus, and posteriorly is continuous with junctional complexes among four esophago-intestinal cells. These four cells are partially enveloped by the gland lobe which basically consists of three gland cells, one dorsal and two subventral. Each gland cell has an anterior process which opens into the lumen of the esophagus through a cuticle-lined duct. The dorsal gland joins the lumen in the anterior portion of the procorpus, whereas ducts of the subventral glands terminate at the base of the metacorpus pump chamber. The subventral glands are predominant in the posterior portion of the gland lobe and are partially ensheathed by a narrow portion of the dorsal gland which extends to within 5 [mu]m of the posterior terminus of the gland lobe. Contents of the dorsal gland include primarily electron dense granules, although rough endoplasmic reticulum (RER) is predominant posteriorly. Secretory granules within the subventral glands vary in morphology and are evenly distributed throughout the two ceils among other organelles, including RER and a large Golgi apparatus. Innervation of the esophagus includes nerve processes which originate from several perikaryons (cell bodies) located in the anterior portion of the gland lobe. The esophagus of males of S. hydrophila is compared with that of other Heteroderoidea, Heterodera glycines and Meloidogyne incognita. Key words: comparative morphology, digestive glands, nonfeeding, secretion.