parasite manipulation biology science

Parasitic manipulations

Who’s in control ?

Having a dog forces us to walk more frequently, finding a cockroach in a meal makes us lose our appetite, and having ticks or lice makes us scratch (and perhaps wash) more often: Animals can cause us to change our behaviour. But those changes are nothing compared with what some animals (especially small ones) do to others.

Nematode worms of the genus Mermithia castrate their insect hosts. A worm, known as Acanthocephala, matures in freshwater fish, but has larval forms that attack small crustaceans. Following an infection, the latter turn bright red and become easy targets for the predatory fish. Unusually red abdomens in some tropical ants, filled with nematode eggs, are also a consequence of a parasite attack, causing ants to resemble tropical fruits and to get eaten by birds. Thus, the nematodes reach their target. Continue reading