This photo of today's parasite,Corynosoma enhydri, illustrates the origin of the term “thorny-headed worms” for the Acanthocephala. This species, like Profilicollis altmani, that you met last month, uses sea otters as its definitive host. It is fairly obvious that once this proboscis is embedded in the wall of the small intestine of a sea otter, it could not easily be dislodged. In rare cases, the proboscis can perforate the wall of the intestine, leading to peritonitis. The number of rows of hooks on the proboscis and the number of hooks per row are important characters in identifying species.
Contributed by Mike Kinsella.