These acanthocephalans have an unusual proboscis. There is a long neck, which expands into a bulb, before the short, terminal hooked portion of the proboscis. The specimen on the left has dark-red-stained pieces of host tissue still attached to the proboscis, because this specimen had to be torn out of its attachment site. This species forces its proboscis right through the intestinal wall of its host, so that the bulb may actually be within the body cavity. These parasites can cause serious pathology when present in large numbers. The specimen on the right has a clean proboscis, and shows the inflated bulb.