Fuck Zombie-Ants. Here's eyeball-parasite-controlled Zombie-Fish!

Scheiß auf pilzgesteuerte Zombie-Ameisen, es gibt augenparasitgesteuerte Zombie-Fische!

Der Parasit in diesem Fischaugenfall ist nochmal ein wenig abgefahrener, als der Ameisenpilz (der seine Opfer einfach nur befällt, woraufhin diese ihr Verhalten ändern, sich von der Ameisenkolonie abwenden und irgendwo hinlatschen, wo sie dann als Parasitengewächshaus kurze Zeit vor sich hinvegitieren und schließlich sterben – nicht bevor sie sogar komplette Zombie-Ameisen-Friedhöfe bilden.)

Dieser hier befällt den Fisch, ändert dessen Verhalten aber im jungen Stadium des Parasits dahingehend, dass das Tier den Raubfischen eher ausweicht (durch reduzierte Schwimmbewegungen also Sichtbarkeit für Raubfische). Wenn der Parasit dann ein fortpflanzungsfähiges Alter erreicht, ändert er das Verhalten des Zombie-Fisches, lässt ihn in heftigeren Schwimmbewegungen durch Wasser planschen und ZACK, Ende Gelände und der Parasit erreicht durch einen neuen Host neue Territorien. Fucking parasites. I love 'em.

New Scientist: Parasite living inside fish eyeball controls its behaviour (Danke Hayo!)

A common parasite that lives in fish eyeballs seems to be a driver behind the fish’s behaviour, pulling the strings from inside its eyes. When the parasite is young, it helps its host stay safe from predators. But once the parasite matures, it does everything it can to get that fish eaten by a bird and so continue its life cycle.

The eye fluke Diplostomum pseudospathaceum has a life cycle that takes place in three different types of animal. First, parasites mate in a bird’s digestive tract, shedding their eggs in its faeces. The eggs hatch in the water into larvae that seek out freshwater snails to infect. They grow and multiply inside the snails before being released into the water, ready to track down their next host, fish. The parasites then penetrate the skin of fish, and travel to the lens of the eye to hide out and grow. The fish then get eaten by a bird – and the cycle starts again.

Many parasites can change an animal’s behaviour to fit their own needs. Mice infected with the parasite Toxoplasma gondii, for example, lose their fear of cats – the animal the parasite needs to reproduce inside.

In a 2015 study, Mikhail Gopko at the Severtsov Institute of Ecology and Evolution in Moscow and his colleagues showed that fish infected with immature fluke larvae swam less actively than usual – making themselves less visible to predators – and were harder to catch with a net than uninfected controls.

Now, the same team has tested rainbow trout harbouring mature eye flukes – parasites ready to reproduce inside their bird hosts. The team found that these trout swam more actively than uninfected controls and stayed closer to the water’s surface.

Both traits should make fish more conspicuous to birds. When the researchers simulated a bird attack by making a shadow swoop over the tank, the fish froze – but infected fish resumed swimming sooner than uninfected ones.