Guybrush

Most lampreys with this behaviour are considered parasitic although many of them do cause a lot of damage to their hosts to the point where the parasite / host relationship is perhaps better described as a predator / prey relationship.

Anyways, I'm done with fish for now. Judging by the yet more feeble attempts at derails, I think it's time to put the scare in ya. Let's talk about one of the most commonly known parasites that also attack humans, the pig tapeworm Taenia solium.





Tapeworms are segmented worms that in some cases can get very long. On their heads, they have a row of "teeth" or "hooks" that they use to hang onto your intestinal wall. Tapeworms are usually hermaphroditic - the first segments are males and the last ones are male. The top segments can then release sperm which travels down your (f.ex) digestive system until they meet the female segments which can then get pregged. The female segments then detach and come out with your poo.

Now, if someone eats your poo, they can get these "eggs" in them. There are other ways, you can eat them yourself if you don't clean your hands or you can live in an area where sewage mixes with drinking water. When you eat these eggs, they will hatch and become the tapeworms second stage, small oncospheres, come out. These invade your tissues where they form cysts.





In the picture above, you can see such cysts found in a slaughtered pig. Humans also get them - and the spooky thing is you don't know where. They could form in your muscles or your liver, but most terrifyingly, they have a tendency to form in the brain and eyes of their human hosts.

Such formation will lead to you losing your brain gradually, leading to a loss of functionality, loss or altered personality, epilepsy and eventually death. Getting them in the eyes causes blindness.

Here's a picture of cystericosis in an eye :





And here's a scan picture of a brain with lots of cysts. It's like a swizz cheese.




The cycle is complete when something eats tissue which has cysts in it. They then acquire the first stage, the intestinal worm part of the lifecycle.

So the next time you travel to someplace where there might be tapeworms, beware. Taenia Solium is not the only one. We have one even up in the arctic on Svalbard called Echinococcus multilocularis which has a vole / fox cycle, but it can also in rare cases survive in humans.

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