Parasites and Zombies!

   Today I just thought I would freak everyone out a little with some horrible stories about, unfortunately real, parasites! How's this for highlighting the amazing-ness of Earth's biodiversity? Here's some of the creepiest parasites in nature:


 Cordyceps unilateralis = Ant Zombies:
      This fungus has spores which enter the body of an ant, where they begin to consume non-vital soft tissues of the ant. They spread through the ant, where they perform some strange mind-control technique by unknown compounds or mechanisms; causing the ant to become a 'zombie', climbing up the stem of a plant and using its mandibles to secure itself.

    The fungus slowly grows through the ant, consuming its tissues and eventually killing it. When it is ready to reproduce, the fruiting bodies sprout out of the head of the ant, releasing their spores to begin the process all over again!

If you want to freak yourself out, here is a video from

the BBC's Planet Earth on the fungus!

Cymothoa exigua or tongue?
    Otherwise known as the tongue-eating louse, this crustacean enters through the gills of a fish and attaches itself to the base of the fish's tongue. It then extracts blood through its front claws for nutrition, eventually causing the tongue to atrophy (die and float off) from lack of blood.

   Horribly, the parasite then replaces the fish's tongue by attaching itself to the fish's tongue muscles. Strangely it then functions as the fish's new tongue, in a form of symbiotic relationship. This is the only known case where a parasite functionally replaces a host organ. Much of this parasite's life cycle and occurence in Red Snappers are detailed in this study by Ruiz and Madrid, from 1992.

 It looks even scarier in real life!

Gordian Worm, aka Horsehair Worm:
    Actually an entire phylum (Nematomorpha) of worms, but the species Spinochordodes tellinii is one of the scariest. The larvae develop inside grasshoppers and crickets, again influencing its host's behaviour. When the worm is reproductively developed it causes the host to seek out and jump into a pool of water.

    The parasite then exits the host (through the anus...) into the water, where it lives and reproduces as an adult, while the unfortunate host inevitably drowns. The species' behaviour and host preferences have been discussed in a paper from 2005 by Schmidt-Rhaesa, Biron, Joly and Thomas.


A Horsehair Worm, exiting its grasshopper host.

    There you have it, 3 pretty scary parasitic species which I think serve to show the interesting diversity our planet can support!