The Digestive System
The nematode digestive system is generally divided into three parts, the stomodeum, intestine, and proctodeum. The stomodeum consists of the “mouth and lips”, buccal cavity, and the pharynx (esophagus). Each of these regions are used extensively in taxonomy and classification of nematodes, as well as providing as indication of feeding habit or trophic group. For example, the buccal cavity of plant parasitic nematodes (and some insect parasites ) is modified in the form of a hollow spear, adapted to penetrate and withdraw the contents of host cells. Predaceous nematodes often have a buccal cavity characterized by teeth or hook-like projections. The buccal cavity of bacterial feeding nematodes is relatively unadorned.