A histochemical study of the cephalic-cervical system of a gnathostomatid nematode,Echinocephalus sinensis,parasite of oysters and rays

Glycogen, protein, succinic dehydrogenase, adenosine triphosphatase, elastin, and collagen were demonstrated within the cephalic-cervical system of adult and third-stageEchinocephalus sinensis. Weak positive histochemical reactions were observed for the presence of sulphated mucosubstances, esterase, acetylcholinesterase, lipids, and acid phosphatase. Tests for the following substances were negative: leucine aminopeptidase, alkaline phosphatase, phosphorylase, neurosecretory substances, and proteases. The present finding seems to support a previous suggestion that this unique system does not have an active secretory role but acts mainly as a hydrostatic organ for the inflation of the headbulb of the worm.