Whale tapeworms, or Polygonoporus giganticus, are not so called because of their enormous size, but because they are found in the intestinal tracks of the Sperm whale. The whale tapeworm can reach over 100 feet in length, and typically is found only in the systems of the whales that have died and been studied. Scientists assume that whale tapeworms behave very similarly to their smaller counterparts.
How Tapeworms Feed
The whale tapeworm, like any other tapeworm, attaches by its head to the intestines of its host. The head is referred to as the "scolex." At the tip of the scolex there is a mass of tentacles sometimes called "sucking grooves" that affix themselves to the intestinal wall and feed. Other tapeworms species use hooks to gather food from the digestive track. Tapeworms lack proper mouths, and instead absorb nutrition from food in the intestines.
Marine tapeworms have plagued water-dwelling animals for more than 270 million years. Fossils of shark feces from the Triassic era, known as coprolite, were found to contain a cluster of tapeworm eggs. One of the eggs already was hatching a developing larva, so recognized by the hooks and tentacles it had grown. Tapeworm eggs are shed routinely through the anus of their host animal, and then eaten by an intermediate organism -- in the case of the sperm whale, it was likely squid -- which then is eaten by a new tapeworm host, completing the cycle.
The larvae of the whale tapeworm also is parasitic, and does more damage on the intermediate organism than the host itself. Once eaten by the intermediate animal, the eggs hatch, and larvae will move into the muscles of the creature. In humans, pork tapeworm larvae can move into the eyes or brain, causing severe neurological damage. This infection is known as cysticercosis. In squid, the juvenile whale tapeworms can live even after the intermediate host has died.
There are over a thousand species of tapeworm on the planet, and every vertebrate animal can host at least one type of tapeworm. Several species can infect humans, the most common are found in improperly cooked beef and pork. An adult whale tapeworm can live in the surrounding intestines for as long as 25 years, passing off segments and spreading to hundreds of other hosts. Unless the sperm whale has died, there is no way to tell whether it has been infected.
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