Echinorhynchus

Echinorhynchus (lit. 'thorny-snout'), a genus of peculiar parasitic worms, forming the class Acanthocephala, which approaches but is quite distinct from the Nematodes. The proboscis armed with hooks, the absence of mouth or food-canal, the exclusively parasitic habit and its results, are characteristic features. There are many species, one of which has been found, but that is all, in man. The adults occur in the alimentary canal of some vertebrates—e.g. pig, duck, pike, perch; the immature forms inhabit small invertebrates (eaten by the final hosts), especially small aquatic crustaceans. See PARASITISM.