Fundamental and applied nematology vol:18 issue:2 pages:123-133
The intestine of the three free-living rhabditid nematodes Caenorhabditis elegans, Panagrolaimus superbus and Acrobeloides maximus was studied using transmission electron microscopy of sections made at three locations along the intestine. Between the three nematode species, ultrastructural differences in cellular components are minor. However, two cell types present in all three nematode species are positioned differently along the intestinal tract. Furthermore, two different types of secretions into the intestinal lumen were identified, one only at the anterior intestine, the second present along the entire length of the intestinal lumen. F-actin staining of fifteen whole-mount nematodes revealed the presence of a well developed, cross-shaped intestinal muscle, only present in Cephalobid species.