This parasite turns shrimps into ravenous cannibals

Researchers from the University of Leeds in Ireland, Queen’s University Belfast, and Stellenbosch University in South Africa have found that a tiny parasite had the power to turn cannibal shrimps into even more terrifying cannibal shrimps.

 

According to the paper, published in Royal Society Open Science, they found that the parasite Pleistophora mulleri not only significantly increased rates of cannibalism in Gammarus duebeni celticus shrimp, but also made them more voracious. Infected shrimp were much faster when it came to chowing down on their victims.

 

“Cannibalism is actually fairly common in nature,” said Dr. Alison Dunn, who led the study. “Our work is the first study to ask if cannibalism is affected by being parasitised.” Dunn is a Reader in Evolutionary Biology in the University of Leeds.

 

Twice the hunger

 

While it’s normal for adult Gammarus duebeni celticus shrimp to eat juveniles, infected zombie shrimp eat twice as much as uninfected adults.

 

PhD student Mandy Bunke, the key researcher in the study, said, “Although the parasite is tiny—similar in size to a human red blood cell—there are millions of them in the host muscle and they all rely on the host for food. This increased demand for food by the parasites may drive the host to be more cannibalistic.”

 

Uninfected adult shrimp tended to avoid eating infected juveniles, lessening the chance of getting infected themselves. On the other hand, infected adults ate uninfected and infected juveniles in equal measure.

 

Dunn added that they also found that infected shrimp caught and ate less prey from other species. “Perhaps cannibalism of smaller shrimp is the only way these sick animals can survive.”

 

Human cannibals?

 

Does this mean that all those zombie horror movies could come true? Are we doomed to go through a zombie apocalypse in the near future?

 

“Our research does not suggest any link between parasites and human cannibalism,” said Dunn. Though the shrimp parasites were able to influence their eating habits, they were cannibals even before infection. “It seems unlikely that a parasite would be under evolutionary pressure to influence cannibalism in humans.” — Bea Montenegro/TJD, GMA News