These Terrifying Parasites Turn Shrimp Into Zombies That Eat Their Young

Canabilism is parenting at its worst.

ByABC News
March 18, 2015, 5:01 PM

— -- A tiny parasite invades a species of Irish shrimp, turning them into zombies who voraciously eat their own babies, a new British research study found.

Millions of pleistophora mulleri parasites flood into the muscles of the gammarus duebeni celticus shrimp, turning their skin milky white and giving them an insatiable appetite for their young, according to the paper published in the latest issue of the journal, Royal Society Open Science.

On their best day, the shrimp are not entirely innocent of cannibalism, the researchers noted. Even uninfected shrimp routinely feast on their own offspring. But infected shrimp are some scary scampi, scarfing down twice the number of juveniles and much more quickly than individuals who escape the parasitic invasion, the authors wrote.

The shrimps' awful parenting skills seem to be driven by muscle damage and a demand by the parasite for more food. Snacking on their own provides an easy meal for the shrimp and satisfies the parasite’s cravings, the researchers speculated.

“Nature is filled with parasitic horror stories,” noted Clive Shiff, a molecular microbiologist with Johns Hopkins Malaria Research Institute, who was not associated with the study.

For example, Shiff described one species of flatworm that annexes a particular species of snail, commandeering its tentacles and blinding it so it no longer tries to hide. Now easy prey, birds swoop down, biting off the mollusks’ heads. This allows the worm to develop into the adult stage inside the bird, Shiff explained.

Another parasite, known as a hairworm, targets grasshoppers, Shiff said, with the larva taking over control of the insect’s brain and nervous system. When the worm reaches adulthood it instructs the grasshopper to commit suicide by jumping into water and drowning itself. There the worm emerges to search for a mate.

The British authors stressed that their research does not suggest any link between the crustacean devastation they describe in their paper and human cannibalism -- though they do point out that over 300 species practice cannibalism, including humans.